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    Geophysics

    Encyclopedia Arctica Volume 1: Geology and Allied Subjects


    Geophysics



    Unpaginated      |      Vol_I-0730                                                                                                                  
    EA-I. (J. Tuzo Wilson)

    GEOPHYSICS

           

    CONTENTS

    Page
    Geophysics and the Arctic 1
    Rotation of the Earth and Definition of the North and South Poles 2
    Precession of the Equinoxes 3
    Wandering of the Earth’s Poles or Variation of Latitude 5
    Secular Motion of the Poles and Continental Drift 5
    Origin of Continents and their Distribution Relative to the Poles 8
    Size, Shape, and Ellipticity of the Earth 9
    Gravity in the Arctic 10
    Isostasy in the Arctic 12
    Seismology 14
    Volcanology 17
    Terrestrial Magnetism 18
    Bibliography 20



    001      |      Vol_I-0731                                                                                                                  
    EA-I. (J. Tuzo Wilson)

           

    GEOPHYSICS

            Geophysics and the Arctic . The nature of the earth is the subject

    of three separate and mutually complementary sciences. Geology, the best

    known and probably the oldest, is concerned with the investigation of the

    solid surface of the earth especially where it is exposed and not hidden

    by the oceans. It developed from the practical requirements and observa–

    tions of miners and road builders. Geodesy is the study of the shape and

    size of the earth or of large parts of it and is a fundamental development

    of surveying and map-making.

            Geophysics is the youngest of this group of sciences and is usually

    defined as physics of the earth. It consists of a series of physical

    studies each concerned with a specific part or aspect of the earth. These

    studies include meteorology, oceanography, hydrology, seismology, terrestrial

    magnetism, and the study of the earth’s gravitational field. Volcanology

    is sometimes included. Other subjects of geophysical investigation are the

    earth’s internal temperatures, pressures and constitution, physical methods

    for determining the age of the earth, and the mechanics of failure and

    movement within the earth.

            Of these subjects, the first three are concerned with the gaseous and

    fluid outer shells of the earth and so are distinct from the other studies,

    002      |      Vol_I-0732                                                                                                                  
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    all of which deal with the solid earth and its magnetic and gravitational

    fields. Meteorology, oceanography, and hydrology may, therefore, be sepa–

    rated from the other subjects and will not be linked with them here.

            Articles on many individual geophysical subjects are included in

    this encyclopedia, but it is fitting that their arctic and polar aspects

    be discussed together and in general terms because the existence and

    definition of the polar regions depends upon the physical fact of the

    earth’s rotation once a day about its axis. All geophysical studies are

    linked and affected by that rotation, although polar characteristics are

    also influenced by the relative position of the sun and earth and by the

    earth’s revolution once a year in an orbit about the sun.

            The earth’s axis of rotation through its poles and the axis of the

    earth’s orbit about the sun are inclined at an angle of 23½° to one another.

    It is this slant which defines the Arctic Circle and the Tropics. It is the

    primary cause of the changes of season, which are more marked at the poles

    than near the equator.

            Rotation of the Earth and Definition of the North and South Poles . The

    axis of the earth is an imaginary line about which the earth rotates once a

    day. This axis passes through the center of the earth. Its intersections

    with the earth’s surface define the North and South Poles.

            The earth makes one rotation on its axis from west to east in exactly

    24 hours of sidereal time, which is equal to 23 hours, 56 minutes, 04.099

    seconds of mean solar or ordinary watch time. The fact that what we ordinarily

    think of as a day, that is the time between two meridian passages of the sun,

    is nearly four minutes longer than the period of the earth’s rotation is

    explained by the small movement of the earth along its orbit each day. Over

    003      |      Vol_I-0733                                                                                                                  
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    the period of a year the sum of these small daily differences adds up to

    give one more sidereal day in a year than there are solar days. The

    fact that the earth revolves around the sun once a year accounts for the

    discrepancy.

            Most of the apparent motion of the sun, moon, and stars is due to

    the rotation of the earth. The reality of this rotation may also be demon–

    strated by means of the Foucault pendulum experiment.

            Since the earth is a solid body, its rotation applies to all parts of

    the earth, and the fact that the sun rises and sets only once a year at

    the poles and other irregularities in the day and night season are all

    subsidiary effects and not due to any change in the rate of the earth’s

    rotation, which is just as regular near the poles as anywhere else. It is,

    in fact, extremely constant. Tidal friction does slow down the speed of the

    earth’s rotation by an infinitesimal amount, but comparison of eclipses

    occurring now and in ancient times provides a delicate control by means of

    which it has been calculated that this increase in the length of the day

    is only about 1/1000 of a second per century. Since the rate may have

    formerly been slightly faster and since the age of the earth is very great,

    the day may have been as short as 5 hours when the earth was formed some

    3 billion years ago.

            The rate of motion of the earth at the equator due to its rotation is

    nearly 3/10 of a mile a second, as can be calculated by dividing the equatorial

    circumference, 25,000 miles, by the length of the day. This motion decreases

    proportionately to the cosine of the latitude until it is zero at the poles.

            Proecession of the Equinoxes . In addition to its daily rotation about

    the axis through its poles and the annual revolution about the sun, the earth

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    has another motion which changes the direction of its axis relative to

    the fixed stars. The polar axis now points almost to the North Star, but

    it did not do so in the time of the ancients and in another 12,000 years

    the celestial pole will be some 47° from its present position and near the

    star Vega. This motion is called the precession of the equinoxes and is

    similar to the precession observed in toy gyroscopes and due to the same

    physical causes. If a top is spinning vertically, it will continue to do

    so, but if it is spinning on a slant the force of the earth’s attraction

    tends to pull the top farther over. The top resolves the forces acting

    upon it according to the laws of gyroscopic motion so that i r t remains spinning

    at the same slant angle, but its axis rotates slowly in the same direction

    as that in which the top rotates to trace out a cone.

            The earth’s axis is inclined at an angle of 23½° to a perpendicular

    to the plane of the ecliptic which is the plane of the earth’s orbit. The

    force of the moon’s and sun’s attraction upon the equatorial bulge of the

    earth tends to reduce this slant of the earth’s axis. The slant angle cannot

    be changed, but its direction is slowly changed in such a manner that the

    earth’s axis sweeps out a circle about the pole of the ecliptic with a period

    of about 25,800 years. Because the force is trying to reduce the slant of

    the earth’s axis, the gyration of the earth’s axis and the proecession of the

    equinoxes is clockwise and opposite to the direction of the earth’s rotation.

            The slant angle to the ecliptic which controls the earth’s relation to

    the sun and moon is not altered by this precession. The stars have no effect

    upon the earth’s latitudes, climates, nor seasons; therefore, the precession

    has no appreciable effect upon these things.



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            Wandering of the Earth’s Poles or Variation of Latitude. Although

    precession causes great changes in the position of the celestial north pole

    among the stars, the position of the earth’s axis relative to the earth

    itself is quite unaffected by precession. There are, however, small annual

    motions of the poles upon the surface of the earth through distances of as

    much as 50 to 60 feet which also cause world-wide changes in latitude of

    the same or lesser amounts. These changes in latitude have been studied

    and the wanderings of the poles analyzed and found to consist of the com–

    bination of two repeated but somewhat irregular motions. One motion causes

    the poles to describe a narrow eclipse with a major axis of about 30 feet

    once a year, the other causes the pole to move around a 26-foot circle every

    433 days, which is the free period of oscillation of the earth.

            These oscillations or wobblings of the earth are believed to be caused

    by different loading in various parts of the earth of ice, snow, water, and

    atmosphere at different seasons. If these movements were to accumulate so

    that the equator and poles moved hundreds of miles relative to places on the

    earth’s surface, then very important changes in latitude and climate would

    result. There is, however, no compelling evidence to show that this has

    taken place. It is true that Köppen, Milankovitch, Vening Meinesz, and

    others have suggested that the earth’s poles have migrated during geological

    time, but the paths, rates of movement, and causes of the movement that have

    been suggested differ so much that the matter cannot be regarded as other

    than speculative.

            Secular Motion of the Poles and Continental Drift . It has been maintained

    that various phenomena of geological history could be conveniently explained

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    by migration of the poles relative to the surface of the earth. Several

    types of argument have been advanced in favor of movement of the poles with which

    the migration of continents relative to one another has also often been

    coupled. They have been chiefly concerned with climate and biology and have

    included the need to explain past variations in climates, and to provide

    m o i gration routes for plants and animals between parts of the earth now

    separated. These movements have also been used as a means of explaining

    geological similarities between shores on opposite sides of oceans and the

    building of recent mountain chains.

            It is undoubtedly true that climates have changed, as coal deposits in

    Greenland and evidence of former glaciation in tropical regions show, and the

    approach of a pole to any region would presumably lead to a colder climate,

    but this cannot be the complete explanation. The recent ice sheets increased

    in size not once, but four times and that simultaneously in North America

    and in Eurasia. Likewise, movement of the poles and drift of continents

    have been used to explain the migrations of plants and animals between

    localities now separate s d by oceans or by climates too cold for them to cross;

    but many other coincidences in the distribution of life cannot be explained

    by any migration or drift, so that additional explanations are necessary.

    Another weakness of these views is that they have usually been presented so

    as to explain certain relatively recent events of geological history, but

    explanations of the events of earlier and larger periods of time have been

    completely omitted.

            Physicists who have examined these views point to the impossibility of

    moving the axis in a rotating body without the action of very great and dis–

    ruptive external forces. They have stated that, if the earth has behaved as

    007      |      Vol_I-0737                                                                                                                  
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    a rigid solid body, a shift of 3° is the most that can be allowed in

    geological time. This is not enough to explain any important climatic or

    geological changes. On the other hand, it might be possible for the axis

    to remain in the same position relative to the main body of the earth,

    while a thin surface layer moved about. Wegener, Köppen, Milankovitch,

    and Gutenberg have advanced such views. In general, they are of the opinion

    that the Pacific Ocean was located at the North Pole in Paleozoic time and

    that movement of the surface of the earth was accompanied by disruption of

    a primitive continental block which fractured in the Atlantic and Indian

    O o ceans. The fragments migrated to form the present continents. According

    to Wegener, there was one primitive continent which he called Pangaea which

    started to break up in the Carboniferous period. Others have suggested that

    the earth was formed with two primitive continents, Laurasia and Gondwanaland,

    located, respectively, about the North and South Poles.

            As possible causes for the disruptions and movements of these continental

    blocks, there do exist several forces in the earth of which the Polfluchtkraft ,

    or force away from the poles, discovered by Eötvös, should be especially

    mentioned. This is a small but definite force acting on continents, tending

    to make them move toward the equator of a spheroidal earth. It cannot have

    ever been strong enough to have acted very freely or the continents would

    form a belt around the equator.

            Vening Meinesz believes that there is a world-wide pattern of shearing

    that has been responsible for preferred lines of weakness in the earth’s

    crust throughout geological time. To explain this, he has suggested that the

    position of the North Pole moved in early geological time from the vicinity of

    Calcutta to its present location. The movement of the earth’s outer shell

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    over its spheroidal interior produced a world-wide shear pattern

            Jeffrays (3) has examined these theories and the strength of the forces

    available to cause movements of the crust, and has concluded that no drift

    of continents relative to one another is possible and that turning move–

    ments of the crust upon the interior are unlikely to have exceeded 5°

    during geological time.

            Although some aspects of these theories of polar m o i gration and con–

    tinental drift are interesting, one can only conclude at present that there

    is no proof that any of them are true. There is much they fail to explain.

    They present many and contradictory views of the supposed movements. There

    are strong arguments against any of the forces being strong enough to cause

    the supposed movements. There is no agreed proof that the poles of the

    earth have ever migrated far relative to the earth’s surface.

            Origin of Continents and their Distribution Relative to the Poles. At

    the present time the continents are arranged relatively symmetrically about

    the poles in a rough tetrahedron with apexes at the four principal land

    masses of North America, Europe, Asia, and Antarctica, respectively. The

    other important land areas lie along the edges that connect these apexes.

    There is, thus, an antipodal arrangement of land and sea masses. It is also

    T t rue that there is a tendency for the nonpolar continents to become wider

    toward the north.

            This symmetry was pointed out in 1875 by Lowthian Green, who suggested

    that a shrinking spherical earth with an inert surface might have tended to

    assume a tetrahedral shape because, of all regular bodies with a given surface,

    the sphere has the greatest volume and the tetrahedron the least. If the earth

    did behave thus, the tetrahedron was symmetrically oriented relative to the

    earth’s pole s .



    009      |      Vol_I-0739                                                                                                                  
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            The suggestion, although ingenious, does not explain why the continents

    are made of a different kind of rock from the ocean floors, for it is known

    that the continents are underlain by a granite layer absent under the

    oceans. Neither does Green’s suggestion explain the structure of the grani–

    tic layer, which is not a uniform material but a complex of belts each

    apparently the root of an old mountain range.

            Theories of continental migration and drift are not able to explain

    these structures either, but suggestions that may prove fruitful are due

    to Lawson and to Lake. They have proposed that the continents have grown

    by accretion of marginal mountain ranges and that each range in turn has

    been underlain and related to crustal fractures. Their ideas are still in

    process of development, but have not yet been able to explain the symmetry

    of the continents about the earth’s axis.

            In fact, the origin and the arrangement of the continents remain an

    unsolved problem.

            Size, Shape, and Ellipticity of the Earth. The Greeks supposed the

    earth to be spherical, and roughly measured its size by determining the

    length of arcs on its surface which subtended known angles at its center.

            On theoretical grounds Newton suggest ion ed that the earth should be

    spheroidal in shape. To determine whether this was so, parties of surveyors

    were sent from France, in 1736, to Peru and to Lapland to measure the length

    of arcs near the equator and as far away from it as possible. They found

    that the length of a degree of latitude did vary, and it is now known that

    a degree of latitude is about 7/10 of a mile shorter at the equator than it

    is near the poles, and that the earth is an oblate spheroid. Now that a

    very large number of arcs have been measured, it has been shown that the

    010      |      Vol_I-0740                                                                                                                  
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    equatorial radius is 3,963.34 miles and the polar radius is 3,949.99 miles.

    The difference between these radii divided by the greater of them is known

    as the ellipticity. It is almost exactly 1/297.

            It has been shown that this particular spheroidal shape is almost

    exactly the shape which would be assumed by a fluid body of the same size

    and mass distribution as the earth.

            The fact that oceans are so uniformly distributed over the earth’s

    surface, and not piled up over the poles or the equator, indeed shows that

    the shape of the earth cannot be greatly out of equilibrium with that

    corresponding to its present rate of rotation. Now it has been mentioned

    the earth’s rate of rotation is slowly changing; it therefore follow s that

    this equilibrium of the earth’s shape and its speed of rotation cannot have

    been inherited from past history. It is probable that the earth’s interior

    is not strong enough to resist long-term stress and that it has adjusted

    its shape.

            Gravity in the Arctic. Intimately connected with the earth’s shape

    is the value of the attraction due to gravity at different points upon its

    surface. The universal and unvarying law of gravitation is that there exists

    a mutual action between masses of matter by virtue of which every mass tends

    toward every other with a force varying directly as the product of their

    masses and inversely as the square of their distances apart.

            If the earth were a spherical, homogeneous planet the gravitational

    attraction of any body would, according to that law, have a constant value

    at all points on the surface. But since the earth is rotating, the intensity

    of the planetary acceleration due to gravity varies with latitude, being

    reduced at any point not on the axis of rotation by the centrifugal force

    at that point. It is, therefore, greatest at the poles and least at the

    equator.



    011      |      Vol_I-0741                                                                                                                  
    EA-I. Wilson: Geophysics

            Since the earth, in addition, is neither homogeneous nor exactly

    spherical, the real relations are complex, but the value of gravity, at

    any latitude can be approximated by an equation.

            Various forms of this equation have been suggested, but that most

    widely used today is known as the International Spheroid of Reference (1930).

            g = 978.049 (1 − 0.0052884 sin2 o −0.0000059 sin 2 2 o )

            From this formula it can be seen that the calculated value of gravity

    varies from 978.049 at the equator to 983.221 at the poles. The meaning of

    this can be illustrated by pointing out that if the same mass were successively

    weighed with a spring balance at one pole and again on the equator, it would

    appear to lose weight in the ratio of these two numbers, that is, the weight

    of the same mass would be ½ % less at the equator than at the poles. [?] as per author ltr 2-7-50

            This formula enables a value for gravity to be calculated for a point

    at any latitude. In addition, the value of gravity may be measured at any

    place by timing the rate of swing of a pendulum. The value of gravity at

    two different places my also be compared by using pendulums or by means of

    another type of instrument known as a gravimeter. In these ways, the value

    of gravity has been measured at many places all over the earth.

            In the vicinity of the North Pole the pioneer deep sea gravity measure–

    ments were made by Scott Hansen, of Nansen’s Fram expedition, on the drift

    of 1893-96, and these remain of the greatest importance. Extensive measure–

    ments with more modern technique were made by V. Kh. Buynitski on a similar

    drift which passed even closer to the Pole during the Sedov expedition of

    1937-40. (The Fram was nearest the Pole at 85°57′ N., the Sedov at 86°40′ N.)

            In general, the accelerations due to motion of a ship at sea are so

    great as to make the measurement of gravitational acceleration very difficult,

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    but when the Fram was frozen in the polar ice these motions were largely

    removed and, in spite of other difficulties, the value of gravity was

    successfully measured at fourteen points across the basin of the Arctic

    Sea. This was the first notable attempt to measure gravity over any

    deep water. The measured values corresponded closely to those calculated.

    The significance of this will be discussed in the next section.

            That was by no means the first attempt to measure the value of gravity

    in the Arctic. In 1736, the party of geodesists sent to Lapland by the

    Paris Academy of Sciences compared the period of pendulum there with its

    period in Paris, while in 1773 Phipps, on his voyage toward the North Pole,

    carried a seconds pendulum which was swung and timed on Spitabergen by

    Cumming. Pendulums were used to measure gravity on several of the arctic

    exploring expeditions which followed the Napoleonic war.

            Modern observations of the value of gravity have been made on spitabergen,

    on Iceland, and on Baffin, Cornwallis, and Victoria Islands of the Arctic

    Archipelago as well as at a few points on the northern mainland of Canada

    and several in Alaska. Surveys have also been carried out in Siberia. In

    Greenland stations have been occupied as far north as Thule, while Norgaard

    recently made an extensive gravimeter survey of southwestern Greenland as

    far inland as the edge of the ic a e sheet. Detailed gravity surveys have

    been made of Finland and Sweden.

            Isostasy in the Arctic . When the value of gravity at any point has been

    both measured directly and calculated from a formula, the difference is known

    as a gravity anomaly. There are various types of anomalies according to what

    correction [?] s are made for elevation of the station and what assumptions are made

    of the nature of the material in the earth beneath the station. By means of

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    a study of these gravity anomalies it has been revealed that the earth

    behaves as though its surface was t a thin, strong elastic layer resting

    upon a deeper plastic layer and that, in general, mountains and continents

    are not held up by the strength of the earth, but rather balance or float

    at a high level because they are light. This is known as the principle

    of isostasy.

            Nansen’s measurements on the Fram were the first made over an ocean

    and showed that the arctic basin is in close isostatic balance with the

    surrounding areas, or, in other words, that the ocean floors are depressed

    because the material below them is heavier that that under the continents.

            Another aspect of isostasy of interest in the Arctic was suggested by

    Jamieson in 1865 when he pointed out that ice sheets represent great loads

    on the surface of the earth. He assumed that these loads would cause outward

    plastic flow below the strong crust with accompanying sinking of the region

    under the ice load, and a reversal of these events with a slow rise of the

    land when the ice melted.

            This has been the subject of careful investigations in the Baltic Sea

    and of a smaller amount of work in West Greenland and in Canada.

            Scandinavia was covered with ice sheets which melted about 10,000 years

    ago. There is no doubt from the evidence of raised beachea that the land

    around the Gulf of Bothnia has risen hundreds of feet since the ice melted.

    It apparently is still rising, showing that there has been a considerable

    delay in the return to levels prevailing before the ice came.

            A similar rise has occurred in Canada and Greenland, but there is no

    agreement in Canada as to whether the rise which has undoubtedly occurred

    is still continuing. Gutenberg and Washburn have, respectively, found evidence

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    that Churchill and Cambridge Bay have risen in historical time. The

    Canadian Government surveys, on the other hand, have been skeptical that

    any rise has occurred at Churchill in the last two hundred years.

            Gravity anomalies have been used in this argument, for, after the

    ice has melted and until the recovery of the land is complete, there

    should be a deficiency in gravity and negative anomalies in the area.

    These have been found in Finland, but the results from Greenland and

    northern Canada are still very limited and can be variously interpreted.

    Much work is in progress in the Canadian Arctic.

            In conclusion, one can say of gravity in the Arctic only that the

    value of the acceleration due to gravity and hence the weight of any mass

    are greater at the poles than elsewhere. The Arctic Sea, although deep, is

    in isostatic balance with its surroundings. There is a most interesting

    problem concerning the way in which the earth recovers from ice-loading yet

    to be elucidated in those arctic and subarctic regions covered with ice sheets.

            Seismology. Unlike most geophysical phenomens, no relationship is

    known to exist between the location of earthquakes and either the poles or

    the the rotation of the earth. Rather, earthquakes occur in belts which

    tend to surround continental shields and to follow belts of young mountains

    and suboceanic ridges. The chief seismic belt surrounds the Pacific Ocean.

    The second in importance extends in an irregular zone from Oceania along the

    Alpine-Himalayan Mountains to Europe. Probably the third most important

    seismic belt includes the many shallow earthquakes which occur along the

    mid-Atlantic ridge from south of the equator to Iceland. North of Iceland

    the ridge is not well defined but the seismic belt continues across the

    Greenland Sea, past Jan Mayen Island, west of Spitsbergen, and directly across

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    the Arctic Sea north of Franz Jose ph f and Severnaya Zeml ay ya Islands to the ✓ ✓

    delta of the Lena. Gutenberg and Richter (2) have listed about fifty

    earthquakes which have occurred along that part of this belt which lies

    within the Arctic Circle, that is, between Iceland and Siberia. All

    the shocks were shallow and had foci at less than 70 kilometers below

    the surface. Most of them were of magnitudes between 5 and 6 on the Gutenberg

    and Richter scale, which means they would usually be recorded at stations

    as far as 10° to 45° away from the epicenters. A few shallow earthquakes

    of the next greater order of magnitude have been recorded from this belt

    especially north of Iceland, west of Spitabergen, and near the mouth of the

    Lena River, but no earthquakes of the greatest magnitudes nor any at greater

    depths than 70 kilometers have ever been recorded. It is within this belt

    that nearly all arctic earthquakes occur.

            This seismic belt across the Arctic Sea and Atlantic Ocean is connected

    with another which extends from the Azores through the Mediterranean and

    Caucasian regions to central Asia as far as Lakes Balkhash and Baikal.

    Taken together, they almost completely encircle with a ring of earthquake

    centers a great part of Eurasia. Within the great area thus enclosed,

    comprising the Baltic and Angara Shields and the Ural Mountains, no major

    earthquakes have been recorded. On the other side of the arctic seismic

    belt across the pole, conditions are nearly as stable. The only earthquakes

    of any consequence that have been recorded are half a dozen near the center

    of Baffin Bay, three near the mouth of the Mackenzie River, and several

    near Bering Strait.

            Many weaker shocks undoubtedly take place, but it is unlikely that

    they would be recorded, as the seismograph stations nearest to the Arctic

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    are those at Reykjavik in Iceland; Scoresby Sound and Ivigtut in Greenland;

    College and Sitka in Alaska; Otomari i o n Sakhalin Island; Vladivostok,

    Irkutsk, Sverdlovsk, and Mosco s w in Russia; and several in northern Europe.

    All the Canadian stations are at present in the southern part of that

    country, but surveys have been carried out with the object of establishing

    a first-class station on Cornwallis Island in the Arctic Archipelago.

            Earthquakes have been felt by observers on Jan Mayen Island, in

    Spitsbergen, and in northern Canada, and severe damage has been done by

    them in Iceland. Shocks are frequently felt in Alaska, originating in the

    princip le al seismic belt of the world which passes through the southern part

    of that country. Many earthquakes of shallow and intermediate depth of

    focus, some of them of the most severe class, have occurred in south-central

    Alaska and along the chain of the Aleutian Islands as far as Kam t c hatka.

            The study of earthquakes not only tells the location of their epicenters,

    but the study of the paths of waves originating in large quakes has been

    interpreted to give much information about the interior of the earth. Some

    waves from earthquakes are reflected from surfaces within the earth, or

    their paths are bent on passing those surfaces which can thus be detected.

            The chief of these is at a depth of 2,900 kilometers or at nearly half

    the radius of the earth. It is the boundary of the core. Below that surface

    the core most probably consists of hot, liquid iron; above that surface the

    mantle is probably basic rock. It is likely that the shape of the core is

    spheroidal and flattened below the poles but no measurements have yet been

    made to prove this.

            Beneath the surface of the continents at a depth of only about 40 kilometers

    is the base of the crust of granitic rocks. It is doubtful if granitic rocks

    017      |      Vol_I-0747                                                                                                                  
    EA-I. Wilson: Geophysics

    exist under any of the deep ocean basins, although there is a layer of

    muddy sediment on the ocean floors. Gutenberg has found specific evidence

    that no granitic crust exists under the floor of the Arctic Sea.

            Volcanology. It has never been seriously suggested that there is

    much connection between the distribution and behavior of volcanoes and

    either latitude or climate. Volcanoes occur in many parts of the world,

    including both polar regions. The two common localities for the eruption

    of volcanoes are on oceanic islands and along seismic belts, in young moun–

    tain ranges, and along island arcs.

            The only volcano known to have been active within the Arctic Circle in

    historical time is on the island of Jan Mayen, which is situated between

    Greenland and the north of Norway, about 71° N., 0 8° W. The island is

    34 miles long and 9 miles in greatest breadth. It is essentially formed

    of two volcanic peaks, of which the more northern, Beerenberg (8,350 ft.),

    is the higher. In 1818, volcanic eruptions accompanied by a fall of ash

    were observed on this peak.

            In 1947, Troelsen discovered in Peary Land, in North Greenland,

    solfataras and hot spring craters which had been in eruption within the past

    few years.

            The most important area of former volcanism in the Arctic is the North

    Atlantic or Thulean igneous province of Tertiary age. This is the name given

    to the volcanic rocks of common age and similar characteristic which are found

    on both coasts of Greenland north of the Arctic Circle, in Iceland, the Faeroes,

    and in the British Isles. Jan Mayen Island is an outlying part of the province

    and the only one in which any activity survives. In East Greenland tens of

    thousands of square miles are underlain by basal d t flows. There are smaller

    018      |      Vol_I-0748                                                                                                                  
    EA-I. Wilson: Geophysics

    areas of lava about Disko Island on the west coast. The relation of the

    minor volcanic activity of northeastern Greenland to the Thulean province

    is not known.

            There are many volcanoes in the subarctic region of Alaska and

    especially along the Aleutian Islands and the Alaska Peninsula. There are

    none in the northern part of that country.

            Terrestrial Magnetism. Extensive surveys both on land and sea have

    established the fact that the earth is a magnetized sphere whose magnetism

    proceeds from within.

            The earth’s magnetic axis is inclined at 11½° to its axis of rotation

    and passes about 750 miles from the earth’s center. This magnetic axis

    intersects the earth’s surface at points known as the geomagnetic poles.

    The north geomagnetic pole is situated on the west coast of Greenland,

    100 miles north of Thule. Due to local irregularities, this is not the

    point where the dip of the magnetic field is vertical. That property defines

    the better-known magnetic poles. The North Magnetic Pole is on Prince of

    Wales Island in northern Canada, in latitude 73° N., longitude 100° W. The

    South Magnetic Pole is in South Victoria Land, Antarctica, in latitude

    72°25′ S., longitude 155°15′ E.

            Curiously enough, the North Magnetic Pole of the earth would in a magnet

    be called a south pole, because it attracts the north poles of other magnets.

            The development of our present knowledge of the earth’s magnetism is an

    interesting example of the slow development of the scientific knowledge. Although

    the ancients had some knowledge of natural magnets, it was the Chinese who

    discovered the north-seeking compass. Introduced into Europe in a crude form,

    it had been in use there for at least three centuries before the time of

    019      |      Vol_I-0749                                                                                                                  
    EA-I. Wilson: Geophysics

    Columbus. He is generally credited with the discovery that the compass did

    not point to the North Star, but that the declination varied from place to

    place. In 1600, Gilbert showed that the earth behaved as a magnetized

    sphere, and a few years later it was observed that the declination under–

    went a secular change at any one place. In 1783, Halley published a theory

    of declination including the supposed position of the earth’s magnetic poles,

    but his concepts were most imperfect. In 1746, the Dobbs Galley came closer

    than any previous ship to what was later known to be the earth’s north magnetic

    pole with a result that all the ship’s compasses ceased to point in any con–

    stant direction. Ellis, who was on board, rejected the obvious explanation

    on the grounds that Halley had placed the pole north of Russia.

            Magnetic observations were made on most arctic voyages, ideas became

    clearer, and in 1831, James Clark Rose located the pole on Boothi s a Peninsula

    at latitude of 70°05′ N. and longitude 96°46′ W. The vicinity was not

    visited again until 1904 when Amundsen considered that the position of the

    pole had not moved greatly. After World War II, it became apparent, however,

    that a change had occurred and the pole was located on Prince of Wales Island

    by members of the staff of the Dominion Observatory. Exactly when and by what

    path the change in position occurred is not known, because there were no

    regular magnetic observatories nearer than College (Fairbanks) in Alaska,

    Meanook (Edmonton) and Agincourt (Toronto) in Canada, and Thule in Greenland.

    To remedy this ignorance of the magnetic field in the Arctic, the Dominion

    Observatory established magnetic observatories at Baker Lake, District of

    Keewatin, in 1946, and at Resolute Bay, Cornwallis Island, in 1948, and

    conducted surveys which resulted in the issue in 1948, of the first accurate

    maps of magnetic dedication in the arctic regions of the Western Hemisphere.

    020      |      Vol_I-0750                                                                                                                  
    EA-I. Wilson: Geophysics

    An unusual feature of the earth’s magnetic field near the m g a gnetic poles is

    its instability. The field is subject to large secular and diurnal variations

    and to a greater number of magnetic storms than elsewhere.

            The c ua au se of the earth’s magnetic field is not fully understood. The

    obvious suggestion that the earth’s iron core is magnetized is almost

    certainly incorrect and so are most of the numerous other suggestions which

    have been advanced. At the present time, there are two chief contending

    theories. One due to Blackett is that a magnetic field is a property of

    rotating matter in the same way that gravity is a property of any matter.

    This theory has the defect that it does not explain the large changes in

    the earth’s field that occur with a period of a few hundred years. Very

    recently, Bullard has suggested that there are convection currents in the

    liquid iron core and that these act as a self-energizing dynamo to produce

    the field. He has not completed the development of his ideas but it appears

    the prob s a ble properties of the core might provide the necessary field, its

    secular changes, and its approximate con a n ection with the earth’s axis of rotation.


    BIBLIOGRAPHY

    1. Daly, R.A. Strength and Structure of the Earth . N.Y., Prentice-Hall, 1940.

    2. Gutenberg, Beno, and Richter, C.F. Seismicity of the Earth . N.Y., Geological

    Society of America, 1941. Its Spec. Pap . no.34.

    3. Jeffreys, Harold. The Earth . 2d ed. N.Y., Macmillan, 1929.

    4. National Research Council. Committee on Physics of the Earth. Physics of the

    Earth . Washington, D.C., The Council, 1931- . The Council.

    Bulletins no.77- .

           

    J. Tuzo Wilson

    Arctic Aspects of Geomagnetism



    Unpaginated      |      Vol_I-0751                                                                                                                  
    EA-I. (David G. Knapp)

    ARCTIC ASPECTS OF GEOMAGNETISM

           

    CONTENTS

    Page
    Introduction 1
    The General Scheme of the Earth’s Magnetism and the

    Earliest Magnetic Data in the Arctic
    2
    Revival of Arctic Work 6
    The Scoresbys, Compass Deviation and Magnetic Intensity 8
    Britain Looks to the Northwest 10
    The Eastern Hemisphere 14
    The Physicists Take a Hand 15
    The Franklin Search 17
    Activity in Alaska 20
    Europe and the Northeast Passage 21
    The International Polar Expedition 23
    Some European Leaders 26
    The U.S. Coast and Geodetic Survey 28
    The Expeditions Continue; Birkeland and Amundsen 29
    Aircraft Expeditions 35
    Canadian Government Work 36
    Magnetic Observatories and the Second Polar Year 37
    Recent Work in Alaska 39
    General Expeditions 41
    Use of the Magnetic Compass in High Latitude 43
    Difficulties of Polar Magnetic Observations 44
    Different Kinds of Transient Magnetic Fluctuations 47
    Modern View of Geomagnetism in the Arctic 49
    Present Outlook 53
    Bibliography Bib. 1 - 35



    Unpaginated      |      Vol_I-0752                                                                                                                  
    EA-I. Knapp: Arctic Aspects of Geomagnetism

           

    LIST OF FIGURES

    Page
    Fig. 1 Relation of magnetic field to position on a

    uniformly magnetized sphere
    6-a
    Fig. 2 Lines of equal magnetic total intensity for 1925,

    according to Fisk
    55
    Fig. 3 Lines of equal magnetic horizontal intensity for

    1925, according to Fisk
    56
    Fig. 4 Magnetic meridian curves for 1925, according to Fisk 57
    Fig. 5 Distribution of magnetic activity, 1932-33. The

    numbers on the lines denote average range of

    total-intensity disturbance in gammas for 60 selected

    days of considerable disturbance. (After Vestine.)
    58



    001      |      Vol_I-0753                                                                                                                  
    EA-I. (David G. Knapp)

           

    ARCTIC ASPECTS OF GEOMAGNETISM

            Introduction . The magnetism of the poles of our planet has intrigued

    the inquiring mind of man since the very beginnings of Western civiliza–

    tion — perhaps more so than any other of the many physical conditions

    characterizing the Arctic. This degree of interest excited by an abstruse

    natural phenomenon is somewhat astonishing, though it has been nourished

    by legends and lore going back to remote cultures and ancient times.

    Nature’s magnet, the lodestone, brought forth wonder and amazement long

    before men had any inkling of its directional proclivities, or of the role

    it was to play in the fabrication of an intricate web of intercourse among

    the peoples of the earth.

            The sailing master who unwittingly steered his ship too close to the

    dread magnetic mountain is well known to readers of the Tales of t T he Arabian check exact name then [?]

    Nights . Entertainments. We are told that the nails that held the vessel

    together were drawn out, putting an abrupt period to the cruise and to the

    episode. This fanciful idea of a forbidden magnetic mountain or isle

    lingered on through medieval times, and was still current at a time when

    the use of a primitive sailing compass conferred a rising surety upon mari–

    time traffic (circa A. D. 1200.) The legendary center of attraction then

    assumed the guise of a faraway point on the earth’s surface (usually relegated

    002      |      Vol_I-0754                                                                                                                  
    EA-I. Knapp: Geomagnetism

    to the Orient or the Arctic) that was thought to g i o vern the compass needle —

    an idea that persists to this day, though clearly discredited by science.

    Hand in hand with this plausible assumption went the rather esoteric fancy

    that the compass drew its power from the region of the heavens surrounding

    the celestial pole, if not from the pole star itself.

            The General Scheme of the Earth’s Magnetism and the Earliest Magnetic

    Data in the Arctic . To exorcise these vaporous notions with solid factual

    data has been a goal of 400 years’ standing, and the end is not yet. Some

    time during the fifteenth century, it came to be realized that magnetic north

    differs systematically from true north by an angle which we call the magnetic

    declination. This is but one of several magnetic elements, others being the

    dip, the intensity, and various components of the intensity. All magnetic

    elements are subject to diurnal, annual, and other variations . However, the

    magnetic declination is itself often called “variation” (of the compass).

    Hence, careful discrimination is needed in the use of the term “variation”.

            The quest for a better knowledge of the magnetic elements, particularly

    the declination, has rightly carried great weight among explorers and seamen,

    and this quest constitutes the “motif” for the present survey of the magnetic

    work done in the Arctic.

            The record begins with Stephen Borough’s voyage (46) in search of the

    mouth of the River Ob in 1556-57. Borough was turned back at Kara Strait.

    Nevertheless, he obtained values of the magnetic de c lination at three points

    on the shores of the White Sea, and at three others in the vicinity of Kara

    Strait. Next in the area was the indomitable William Barents, who recorded

    several values of the magnetic declination beyond Kara Strait and along the

    northwest coast of Novaya Zemlya, as well as at Bear Island and in

    003      |      Vol_I-0755                                                                                                                  
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    Hinlopen Strait, Svalbard. His data were obtained on the first and third

    of his voyage s (47).

            Meanwhile, data from a different quarter resulted from the remarkable

    voyage of John Davis into Baffin Bay (48) in 1587. We have values of declina–

    tion at two points, one his farthest northing near Söndre Upernivik, Greenland,

    and the other in the north end of Cumberland Sound.

            During this period, under the stimulus of the general quickening of

    maritime activity, there were published in London two books that marked

    important advances in our understanding of the earth’s magnetism. Ronert

    Norman in The New Attractive (1581) announced his discovery of the fact that

    the north-seeking end of a suitably balanced magnet makes a definite and

    (in Britain) a considerable downward angle with the horizontal. He supposed

    this angle of dip to be a direct witness of focus or “point respective” that

    lay deep within the earth, disparaging the idea then current of a celestial

    center of attraction. William Gilbert’s treatment of this problem in the

    monumental De Magnete (1600) went a step further and showed the approximately

    correct relation of dip to “latitude” on a magnetized sphere, varying from

    zero on an equatorial line to 90° at two polar points. With Gilbert, this

    relation took the form of an empirical construction derived so as to fit

    experimental data. Gilbert asserted (on what now seem scant grounds) that

    the earth actually behaved like such a sphere. This image was a bold advance

    for the times, and still holds favor as a fair over-all description, though

    the pattern is warped and distorted to a degree undreamed of by Gilbert.

            Had Gilbert not died shortly after the publication of his book, he

    would have received gratifying confirmation of his conjecture regarding the

    dip, at the hands of more than one explorer. George Weymouth in Frobisher Bay

    004      |      Vol_I-0756                                                                                                                  
    EA-I. Knapp: Geomagnetism

    in 1602 (49), Henry Hudson in the Barents Sea in 1608 (50), and William

    Baffin in Svalbard (Spitsbergen) in 1613 (51), all made dip observations

    showing that in these high latitudes the dip did indeed become quite large.

    These navigators also added diligently to the store of data on declination

    in the North, as did several other explorers during the period 1609-1631.

    Specifically, we have data for the Barents Sea by J. C. May (52); for the

    Pechora River by Josias Logan (53) and William Gourdon (54); and for

    Svalbard by Jonas Poole (55), Robert Fotherbye (56), and Maerten Remmertsz (57).

    Baffin observed the declination frequently; we have data from all except the

    third of his five voyages, including one value of 56° W. (greater than any

    previously observed anywhere) at the extreme latitude of 77°30′ N. in Smith

    Sound. His work provided a significant access of new data for Davis Strait.

    Further data for this general area, including Hudson Bay, resulted from the

    work of William Hawkridge (58), Luke Foxe (59), and Captain James (60).

            With the lapse of interest in a northern route to be Orient, the

    growth of knowledge about magnetic conditions in the Arctic came to a halt.

    No new data are recorded for nearly a century, except a few obtained by

    John Wood (61) in 1676 along the coast of Novaya Zemlya. During this period

    there was considerable activity in lower latitudes, reflected in the discovery

    of secular change in the horizontal direction of the field (1634), the inven–

    tion of isogonic charts (1641), the disquieting evidence of transient

    diurnal fluctuations in the earth’s magnetic field (1685), and the publica–

    tion of what was probably the first isogonic chart to be based on a compre–

    hensive assemblage of data, the famous Atlantic chart of the English

    Astronomer Royal, Edmond Halley (1701).



    005      |      Vol_I-0757                                                                                                                  
    EA-I. Knapp: Geomagnetism

            The writings of Kircher, Halley, and Musschenbroek show that natural

    philosophers were taking an increased interest in geomagnetism as a branch

    of science. Halley had grappled at an early date with the difficult problem

    of the gross regional distortions that confronted Gilbert’s idealized model.

    His interpretation reflects the first of repeated attempts to systematize

    the phenomena by postulating secondary poles. Schüt s z (27) discusses Halley’s

    ideas from a more up-to-date point of view. While this particular scheme is

    out of favor today, its ultimate influence as a spur to magnetic exploration

    was undoubtedly strong, especially so in the Arctic. Halley also was the first

    to suggest a connection between the earth’s magnetism and the aurora borealis;

    this was shortly before the discovery of irregular magnetic activity, which

    within a few years was claimed to be directly linked with the aurora, though

    the reality of this connection remained in dispute for nearly a century.

            William Whiston made extensive observations at many places in England

    to determine the dip and the time of oscillation of a magnetized needle.

    His needle was set up to oscillate, sometimes in the magnetic meridian plane

    about the line of dip, and sometimes laterally in the horizontal plane. He

    arranged to have needles mounted aboard ships, and one such instrument was

    sent on a voyage into the Barents Sea (62), where its time of oscillation

    was observed. Whiston’s writings of 1721 and 1724 are thus the earliest

    known that deal experimentally with the strength or intensity of the earth’s

    magnetic field. Subsequent scattered observations, oddly enough, lent

    support to the idea that the total intensity of the earth’s magnetism was

    everywhere the same, a notion that prevailed for a long time. Not until

    many years later was a more truthful general principle enunciated connecting

    the intensity with the latitude.



    006      |      Vol_I-0758                                                                                                                  
    EA-I. Knapp: Geomagnetism

            Although there is no strict relation between latitude and magnetic

    field, it is useful to know the relation which would exist if the earth

    were uniformly magnetized parallel to its axis of rotation. In Figure 1,

    let O be a point on the surface of such an earth. Draw OA parallel to the

    axis of rotation, and of such length that it represents (on some chosen

    scale) the value of the magnetic field at the Equator. Draw OB tangent to

    the surface; angle AOB is then the latitude of O . Draw OB tangent to the sentence repeated Space for Fig. 1?

    surface; angle AOB is then the latitude of O .
    Draw AB perpendicular to OB

    and extend it to C , so that BC = 2 AB . Then OC represents the magnetic field

    at point O . The lengths OB , BC , and OC show (on the chosen scale) the

    horizontal, vertical, and total intensities, respectively; and angle BOC

    is the dip. On this idealized earth, the horizontal intensity would vary

    as the cosine of the latitude, whereas the dip would have a value whose

    tangent is twice that of the latitude.

            Revival of Arctic Work . The arctic data thus far discussed have all

    pertained to two circumscribed areas — one lying between Svalbard and the

    Kara Sea, the other in the environs of Davis Strait. We now turn to a new

    segment of the Arctic, namely that disclosed in the Kamchatka Expedition of

    Captain V. I. Bering, made in 1725-30 in the interest of the Russian

    Empire (64). This voyage yielded the earliest data on the declination

    along the coast of Kamchatka and in Bering Strait.

            Closely after this venture, we come to the concerted Russian undertaking

    known as the Great Northern Expedition (66), in which various teams of explorers

    collaborated on a vast scale to map the arctic shore line of the Eurasian

    continent from the Kara to the East Siberian Sea, while the discoveries of

    Bering were extended and consolidated by himself and others, sailing as far

    006a      |      Vol_I-0759                                                                                                                  

    Relation of magnetic field to position

    on a uniformly magnetized sphere.

    FIGURE 1.



    007      |      Vol_I-0760                                                                                                                  
    EA-I. Knapp: Geomagnetism

    as the Gulf of Alaska. Compass data were recorded by all these parties,

    the names of the observers or leaders being Skuratov, Ovtayn, Sterlegov,

    and D. and K. Laptev.

            In the same period there were several British voyages into the upper

    reaches of Hudson Bay. One which yielded new material on the declination

    in that area was the expedition (67) , of Francis Smith and William Moore

    in 1746-47.

            The expansion of European magnetic exploration by land began now to

    impinge on the A a rctic Z z one at various points. We may mention in particular

    the work of Beliaev (68), Rumovaky (69), Pictet (70), and Mallet (71) in

    the White Sea region, and of Holm (72), Anders Hellant (73), and later

    ew we nörn (74) on the Scandinavian Peninsula. The scope of Holm’s work

    extended in 1766 to Husstappen Island, near North Cape, whereas Hellant

    and Löwenörn observed declination at numerous stations in arctic Sweden

    between 1748 and 1786. On the far side of the arctic basin, the well-known

    exploring expedition of the Russian explorer and merchant, N. Shal a urov (75),

    yielded significant new data for the remote Chukotsk Peninsula.

            A few data for points in the Barents Sea resulted from the Chichago f (76)

    and Rosmyslov (77) expeditions, whereas William Bayly (78) observed both

    declination and dip at North Cape in 1769. For the Svalbard area we have

    data credited to Claessen, given in A. R. Martin’s diary of his 1758

    voyage (79), as well as the dip values resulting from the J. C. Phipps expedition (80) of 1773. Some data resulted from a hydrographic line missing cf. original p. 8

    survey (81) by the Russian Navy in 1779, in the Norwegian Sea, and from the

    work of Abrosimov and Ivanov in the White Sea area in 1800 (82).

            In the Bering Straig region, the definitive explorations of Captain

    James Cook (1778-79) yielded further data (83) covering stretches of the

    008      |      Vol_I-0761                                                                                                                  
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    Pacific and arctic coasts of both Alaska and the Asiatic mainland. Special

    attention was given to the ast r onomical and magnetic work which was brought

    to new levels of accuracy in that the recently developed and improved

    sextant was used for obtaining the sun’s altitude. The magnetic program

    included both declination and dip. Subsequent data are due to work under

    Russian auspices in this vicinity by Sarychev and Billings (84), by Gilev

    (85), and by Kotzebue (86). Somewhat to the westward, the surveys made in

    1809-10 by the exiled M. M. Hedenström (87) in the region of the New Siberian

    Islands provided new and valued data for those islands and for their mainland

    approaches.

            The Scoresbys, Compass Deviation and Magnetic Intensity. With the open–

    ing of the nineteenth century we come first to the work of two redoubtable

    Scotsmen, the arctic navigators William Scoresby, Senior and Junior (88).

    Not only did their many successful whaling voyages reveal hitherto unknown

    regions (e.g., much of the remaining east coast of Greenland) but their

    lively interest in scientific work and their keen discernment had lasting

    effects on the diverse topics touched by their many inquiries. William

    Scoresby, Junior, took as one of his chief interests the magnetism of iron

    and steel and the deviation of the compass resulting from the magnetism of

    a ship. He conducted some of his experiments on these matters in 1822 while

    the Baffin was beset in the ice at latitude 79° N., discovering a new and

    more effective technique of utilizing the earth’s magnetism to induce

    polarity in steel rods.

            The challenging task of reducing to rational law the deviation and

    compensation of the compass was to attract some of the ablest scientific

    minds of that day and the next before it found full elucidation. A start

    009      |      Vol_I-0762                                                                                                                  
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    had been made by William Wales, the astronomer on Cook’s second voyage,

    and important advances are due to Matthew Flinders, Peter Barlow, and

    other contemporaries of the younger Scoresby. As Scoresby himself was

    well aware, these effects may impose stringent limitations upon navigation

    and hydrography in the Arctic and elsewhere. They are particularly serious

    if a craft goes into regions where the ratio of the horizontal to the

    vertical intensity becomes very small, as it does in much of Arctic America.

    Scoresby’s data on the magnetic declination have special significance and

    validity, for he remarks (89): “All the magnetic observations, whether

    for determining the bearing of the land, or the azimuth of the sun, were

    taken at the mast-head, because this was the only part of the ship where

    compass-bearings could be relied upon. In every other part of the ship,

    indeed, that could be conveniently resorted to, there was so much ‘local–

    attraction’ or deviation,’ that observations taken therein, with the

    magnetic needle, were useless.” On some of his voyages vibrations of a

    dip needle were taken in order to determine the total intensity.

            This period was marked by an increasing awareness of the fact that

    the intensity of the earth’s magnetic field is one of the elements whose

    distribution must be charted for a fuller understanding of the whole

    phenomenon. The measurements made by Paul de Lamanon as a participant

    in the doom-ridden expedition (90) of La P e é rouse (1785-88) and mentioned ✓ accent

    by him in a communication to the Paris Academy of Sciences before disaster

    overtook the expedition, reinforced by the observations made by Alexander

    von Humboldt on his travels in South America (1798-1803), had forced a

    final recognition that the intensity was not everywhere constant but

    instead underwent a twofold increase from equator to pole.



    010      |      Vol_I-0763                                                                                                                  
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            Several P p hilosophers were again seeking to systematize and generalize

    the accrued data on the declination and its secular change. The most

    penetrating and fruitful of these studies was that of the Swedish astronomer

    Christopher Hansteen, who published in 1819 his celebrated work Magnetismus

    der Erde (12). This book assembled all the magnetic data to which the

    author had access, and presented his refined and elaborated hypothesis of

    two distinct centers of convergence of the magnetic pattern in each polar

    zone. This proposal depended, of course, on the general trends of the

    magnetic lines that could be perceived in high latitudes, rather than on

    direct observation of the magnetic poles.

            Britain Looks to the Northwest . Obviously, the efforts of Hansteen

    and his contemporaries were sorely hampered by the gap of Arctic America.

    Whaling craft now frequented Baffin Bay, and there had been a voyage led

    by Richard Pickersgill (91) in 1776 that yielded data for seven points in

    Davis Strait. But the area to the north and west was an almost complete void

    on the map, stretching over a full hundred degrees of longitude, prior to

    the great series of British expeditions that was inaugurated in 1818 under

    the encouragement of scoresby’s arctic achievements. Though not a success

    in the popular view, the dual expedition of that year yielded highly valued

    new magnetic data, the work of James Clark Ross and Edward Sabine in Baffin

    Bay (92) and of John Franklin and Alexander Fisher in the Svalbard area (93).

    The observations of Ross and Sabine were made on the ice of Melville Bay,

    well clear of the effects of the ship’s magnetism, and they included dip

    and intensity measurements as well as declination.

            After this beginning, the intricacies of what we know today as the

    Parry Archipelago began to give way before a vigorous renewal of the quest

    011      |      Vol_I-0764                                                                                                                  
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    for the Northwest Passage; and each new exploration brought forth new

    magnetic data of a gradually expanding scale and scope that reflected the

    growing urgency and significance attached to this phase of arctic explora–

    tion by the great nineteenth-century physicists. During William Edward

    Parry’s memorable voyage through Lancaster Sound and into Barrow Strait

    in 1819-20 (94), Sabine obtained data at six stations in the vicinity of

    Melville Island, and he conducted at Winter Harbour protracted observations

    of the time variations, something that had not previously been attempted

    in polar regions. This arduous program, carried out on the very first

    voyage to go across the intriguing zone of southward streaming of the

    magnetic lines, was an earnest of the subsequent endeavors by which Sabine

    was to advance so greatly the understanding of geomagnetic phenomena. It

    is also worth noting that Sabine, being already acquainted with Flinders’

    earlier experiments on compass deviation, seized his chance during this

    voyage to test and refine the conclusions of Flinders by means of experiments

    under arctic conditions.

            Competent work was done on Parry’s two subsequent voyages as well, with

    the assistance in 1821-23 of Fisher and James Ross and in 1824-25 o r f Ross,

    Henry Foster, and F. R. M. Crozier — the same Crozier who was later to

    perish with the last Franklin expedition. On the second voyage (95),

    contrasting curves of daily variation were obtained at the two wintering

    stations in the southwest and northwest corners of Foxe Basin. Parry’s

    third voyage (96) yielded new data for Prince Regent Inlet, including

    extended readings at Port Bowen by means of variation instruments. The

    expedition’s proximity to the magnetic polar locality was indicated by the

    determinations of horizontal intensity, the least thus far attained.

    012      |      Vol_I-0765                                                                                                                  
    EA-I. Knapp: Geomagnetism

    A large pivoted needle constructed especially for reading the daily variation

    was set up, but the directing force upon it was too weak to overcome the

    slight friction of the pivot. It was necessary to suspend the needle by

    means of a silk fiber before it would respond. The same difficulty made

    the ship’s compass useless and was a chief factor in Parry’s failure to

    complete the exploration of the shores opposite the Brodeur Peninsula, as

    he had hoped to do on this third voyage. There had at long last been reached

    the zone that most nearly corresponded with the ominous magnetic isle of

    legend and fancy. Strangely enough, twenty-three years later this very

    locality was to witness the undoing of a great company of intrepid men,

    albeit the compass problem was not so great a difficulty as the overwhelming

    obstacle placed athwart the Northwest Passage by a jealous and impassive

    Neptuns, in the form of prodigious quantities of ice pushing relentlessly

    southward from Viscount Melville Sound.

            This third voyage of Parry’s was also the occasion for some preliminary

    daily variation readings (97) made by Foster during a brief stay in the

    Whale Fish Islands (Disko Bay), not far from the present Godhavn, where

    a magnetic observatory is now in operation. F. W. Beechey’s cooperating

    expedition in the Blossom , which is credited with the discovery of Point

    Barrow in 1826, was likewise a source of magnetic results, the work of

    Beechey, Edward Belcher, J. Wainwright, and J. Wolfe (98). Simultaneously,

    a voyage of the French whaling captain L.-A. Gu e é don (99) added to the store accent

    of data for the Baffin Bay area.

            Meanwhile, the quest went forward by land. The Franklin expeditions

    of 1819-22 and 1825-28, which at a cost of seven lives mapped two great

    rivers and most of the arctic coast of the continent, yielded magnetic data

    013      |      Vol_I-0766                                                                                                                  
    EA-I. Knapp: Geomagnetism

    along with the other results. The magnetic work of the earlier journey (100)

    was divided amon t g three men — Franklin, George Back, and the ill-fated

    Robert Hood. On the second expedition (101), E. N. Kendall and Dr. John

    Richardson shared this work with Franklin and Back. These first explora–

    tions in the Canadian Arctic reached a fitting climax in 1829-33 with the

    privately sponsored expedition of John and James C. Ross (102). This out–

    standing enterprise was prolific in both geographical and geophysical results,

    but its chief contribution was probably the series of dip observations made

    in the magnetic polar area, which James C. Ross found to be centered on the

    west coast of the Boothia Peninsula, nicely countering the C c elebrated

    achievement of L. I. Duperrey, who in 1822-25 had traced the magnetic

    equator across two oceans.

            Anxiety over the delayed return of the Rosses led to the organization

    under George Back of a relief expedition (105) which in 1833-35 explored

    the Great Fish River (since renamed the Back River). Back also led an

    expedition (107) to Repulse Bay in the Terror in 1836-37. On both occasions

    he secured valuable magnetic data supplementing those of Ross and his

    observations on the coincidence of auroral and magnetic activity, subse–

    quently confirmed by Lottin and Bravais at Bossekop, helped to place this

    remarkable connection beyond dispute. James Ross was engaged in the

    magnetic survey of England for a time after his return from the Arctic and

    prior to his crowning antarctic explorations. He also traveled in the

    summer of 1836 to Davis Strait and Baffin Bay, observing the dip at two

    points on the Greenland coast. Further magnetic data for the arctic

    seaboard region of mainland Canada accrued from the explorations of the

    intrepid Thomas Simpson (108 ) and the remarkable John Rae (109), both men

    of the Hudson’s Bay Company.



    014      |      Vol_I-0767                                                                                                                  
    EA-I. Knapp: Geomagnetism

            The Eastern Hemisphere . During the same period (1820-40), magnetic

    work was being actively pursued in other arctic sectors as well. Frederick

    von Lütke’s exploration (110) of the west coast of Novaya Zemlya in 1821-24

    yielded new compass data for that area. In 1823, the work of the Clavering–

    Sabine pendulum expedition (111) included Sabine’s measurements of dip and

    total intensity at each of his four stations — Trondheim, Hammerfest, a

    Norway Island (Svalbard) station, and Pendulum Island, high on the east

    coast of Greenland. Further data for 18 points in and north of the Svalbard

    Archipelago are credited to Parry, Foster, and Ross as a result of the

    poleward thrust (112) led by Parry in 1827. In the same year, the Danish

    geologist B. M. Keilhau (113) obtained numerous values of dip and intensity

    along the Norwegian arctic coast and in Svalbard. Other observers contri–

    buted to the magnetic knowledge of Svalbard and the east coast of Greenland,

    namely, W. A. Graah (115) in 1829, the ill-starred J. de Blosseville (116)

    in 1833, and Victor Lottin as a participant in the search expedition (117)

    for Blosseville in 1835-36. Lottin, M. A. Bravais, C. B. Liljehoek, and

    other members of the Recherche expedition of 1838-40, led by Paul Gaimard

    (118), obtained further magnetic and auroral data in the North Cape area,

    including an important series of variation readings at Bossekop occupying

    several months. Magnetic data were also obtained by P. K. Pakhtusov in two

    expeditions to explore Novaya Zemlya, in 1832-35 (119; 120), and also by

    Moiseev and Ziwolka (121).

            Magnetic explorations in the Siberian Arctic were also continuing.

    Especially fruitful were those of Ferdinand P. von Wrangel (122) and P. F. Anjou

    (123), with P. T. Kozhmin, including in their scope seven stations in the

    New Siberian Islands. Hansteen, desiring to test his hypothesis of a

    015      |      Vol_I-0768                                                                                                                  
    EA-I. Knapp: Geomagnetism

    secondary Siberian focus of intensity (which had been conjectured from

    the pattern of declination), made a journey through Siberia with Christian

    d D ue and Adolph e Erman, skirting the Arctic Circle. Extensive meassurements ✓ ✓

    made at many points bore out the hypothesis. This was in 1828; Erman con–

    tinued eastward across the Pacific and around the globe (124). Another

    round-the-world voyage was Lütke’s in the Seniavin e in 1826-29, during

    which data were obtained for the Bering Strait area and for Sitka (125).

    Further data for the Siberian Arctic are due to the land explorations (126)

    of A. T. von Middendorf in 1843-44. Veinberg (40) credits data for the

    north of Europe during this period to a number of observers.

            The Physicists Take a Hand . An interesting result of the earlier

    arctic work of Sabine and others was his deduction that the point of maximum

    total intensity was not, as had been supposed, coincident with the dip pole

    spotted by Ross but lay a long way to the south of it. Sabine was instru–

    mental in arranging for a series of measurements to be made in the interior

    of Canada for tracing out this focus of maximum intensity. The work was

    done in 1843-44 by J. H. Lefroy (127). Sabine found his proposition amply

    confirmed, just as had Hansteen with respect to the corresponding Siberian

    focus. During Lefroy’s survey he made extended observations on the daily

    variation at Fort Chipewyan on Lake Athabaska, and at Fort Simpson (136).

            While Poisson and Airy, and later Archibald Smith, were delving into

    the mathematical basis of compass deviation and the magnetism of ships, there

    was a great upsurge of experimentation and discovery in the newly opening

    field of electromagnetism. Basic laws began to emerge in rapid succession.

    It became clear that the earth’s magnetic field afforded a convenient working

    medium on which to base the measurements of electric current, but the

    016      |      Vol_I-0769                                                                                                                  
    EA-I. Knapp: Geomagnetism

    measurement of the magnetic field itself was in an unsatisfactory state,

    because all intensity readings were directly dependent on the strength of

    magnetization of the needles used, a shifting and uncertain factor. This

    handicap p was brilliantly dispelled by the work of Karl Friedrich Gaus s of

    Göttingen. He developed, along the lines of suggestions by Poisson, a

    method of measuring both the horizontal intensity of the earth’s field and

    the magnetic moment of the magnet, by a coordinated experiment involving

    oscillations and deflections with a single instrument. In almost every

    respect the Gaussian technique was far superior to the older methods, and

    it placed intensity measurement on a uniform basis such that henceforth

    the determinations of different observers, made apart, could be directly

    compared and coordinated.

            Gauss likewise brought a fresh approach to the problem of generalizing

    the distribution of the earth’s field. He concluded that all studies which

    sought to interpret the earth’s magnetism in terms of supposed dominant and

    secondary poles suffered an intolerable lack of generality. In 1838 he

    published the celebrated Allgemeine Theorie des Erdmagnetismus , embracing his

    versatile invention of spherical harmonic analysis. The distribution of a

    function over any spherical body could now be represented mathematically

    with any desired precision, simply by utilizing a sufficient number of terms

    in the infinite series that comprised his formulas.

            Gauss was one of the first to perceive the importance of making continuous

    observations of daily variation and other transient phenomena of the earth’s

    magnetism, particularly in regard to a host of minor features that had not

    been discernible in the earlier, grosser measurements. He shares with

    Weber, Humbol td dt , and Sabine the credit for promoting the establishment of

    magnetic observatories at widely separated points.



    017      |      Vol_I-0770                                                                                                                  
    EA-I. Knapp: Geomagnetism

            These achievements of Gauss and his contemporaries lifted all magnetic

    explorations to new levels of accuracy and significance, and at the same

    time they underscored sharply the deficiencies of existing surveys and

    especially the need for more and better data in the Arctic.

            The Franklin Search. Following the work of Ross, Back, et al . , in the

    1830’s, there was a brief pause in the exploration of the Parry Archipelago.

    The calm ended abruptly with the epi d c final expedition of Sir John Franklin,

    trapped in the ice that battered his ships inexorably against the shoals of

    Victoria Strait, after a smooth passage down Peel Sound and past the magnetic

    pole toward King William Island. This expedition was equipped for an

    intensive program of hourly magnetic readings to be made at any wintering

    stations which it might take up; doubtless such a program was fulfilled

    during the first winter at Beechey Island, and it can be assumed that magnetic

    observations were obtained in other areas as well. Whatever scientific

    records accrued, however, were lost without trace, presumably being destroyed

    with the ships. The nest three decades, from 1848 to 1879, witnessed a fever

    of activity in this area devoted first to the vain hope of releasing the 129

    men or any survivors, then to the search for traces of their desperate final

    wanderings, and at last to the development of the many new discoveries cast

    up during the search.

            Like the Franklin group itself, many of the expeditions that conducted

    the Franklin search were well equipped with magnetic instruments suited to

    the region of near-vertical magnetic flux. Others contributed less accurate

    determinations made with ships’ compasses. The schedule given below shows

    the areas in which magnetic data of one sort or another were obtained by

    the various Franklin search expeditions or subexpeditions, together with the

    names of the observers.



    018      |      Vol_I-0771                                                                                                                  
    EA-I. Knapp: Geomagnetism

           

    Group I. Pacific Approach

            Moore cruise of 1848-49, ship Plover (128); Bering Sea; data by T. E. Moore.

            Kellett cruise of 1848-49, ship Herald (129); Bering and Chuckchi e Seas;

    data by H. Kellett.

            Kellett cruise of 1850, ship Herald (130 ) ; Bering Sea and Kotzebue Sound;

    data by H. Kellett.

            Maguire cruise of 1852-54, ship Plover (131); observations supervised by

    Rochfort Maguire at Point Barrow during two winters, totaling 17 months

    of hourly declination readings.

            Collinson expedition of 1850-54, ship Enterprise (133); Bering and Beaufort

    Seas, Coronation Gulf, and Victoria Strait; data by Richard Collinson.

            McClure cruise of 1850-54, ship Investigator (134); Prince of Wales and

    M’Clure Straits; data by R. J. Le M. M’Clure.

           

    Group II. Atlantic Approach

            Ross-Bird expedition of 1848-49, ships Enterprise and Investigator (135);

    Lancaster Sound; data by J. C. Ross, W. E. J. Browne, and Fred Robinson.

            Richardson-Rae expedition of 1848-49, by land (136); Fort Confidence, and

    vicinity of Dolphin and Union Strait; data by John Richardson and John Rae.

            Austin expedition of 1850-51, ships Resolute and Assistan t ce (137); Peel

    Sound; data by Robert C. Allen and W. E. Ommanney.

            Kennedy expedition of 1851-52, ship Prince Albert (138); environs of

    Somerset Island; data by William Kennedy and J. R. Bellot.

            Inglefield expedition of 1852, ship Isabel (139); Hound Islands (Disko Bay);

    data by E. A. Inglefield.

            Belcher expedition of 1852-53, ships Resolute and Assistance (140);

    Barrow Strait and Wellington Channel; data by J. N. Allard, R. C.

    Allen, E. Belcher, R. V. Hamilton, H. Kellett, G. F. M’Dougall, and Richard Roche.



    019      |      Vol_I-0772                                                                                                                  
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            Inglefield expedition of 1853, ship Phoenix (141); Melville Bay and Beechey

    Island; data by J. R. Bellot, who lost his life on this cruise.

            Grinnell-Kane expedition of 1853-55, ship Advance (142); Kane Basin; data

    by E. K. Kane and August Sonntag, including hourly values of the

    declination at an observatory on the Greenland coast above Etah.

            M’Clintock expedition of 1857-59, ship Fox (143); data by F. L. M c Clintock,

    including ice and shore observations in Baffin Bay and on King William

    Island and nearby points, and an important series of hourly readings

    at Port Kennedy, the wintering station near Bellot Strait.

            Hayes expedition of 1860-61, ship United States (144); shore area centered

    at Umanak Fjord, Greenland, also Ellesmere Island; daily variation

    readings at Port Foulke, the wintering station near Cape Alexander,

    Greenland; absolute observations included three elements; data by August

    Sonntag, M. G. Radcliff e , and S. J. McCormick.

            Hall expedition of 1864-69, by land (145); Melville Peninsula to King

    William Island; data by Charles Francis Hall.

            Hall expedition of 1870-73, ship Polaris (146); North Greenland coast,

    especially Hall Land and Hall Basin; data by Emil Bessels, Richard W.B.

    Bryan, and F. Meyer. Beyond the above data, protracted hourly readings

    were made in winter quarters but could not be saved.

            Nares expedition of 1875-76, ships Alert and Discovery (147); shore stations

    facing, and sledge journey into the Lincoln Sea; data by A. H. Markham,

    Pelham Aldrich, R. H. Archer, and L. A. Beaumont. Instructive notes and

    magnetic charts drawn up for the guidance of this expedition have been

    published (17). They include valuable summaries of the magnetic results

    produced by earlier expeditions.



    020      |      Vol_I-0773                                                                                                                  
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            Activity in Alaska . Under the stimulus provided by the investigations

    of Gauss, Humboldt, and Sabine, and as a direct result of the influence of

    these and other eminent scientists of the time, there was in the 1840’s

    an active program by which several countries established magnetic observa–

    tories to learn more about the transient fluctuations of the earth’s

    magnetism. In 1842 the Russian authorities set up one of their observatories

    on Japonski Island near Sitka. (There had been in the period 1832-35 a program

    of magnetic work at this post under Wrangel (125a)). It functioned continuously

    for eleven years, and again from 1857 to 1864, providing the earliest know–

    ledge of the daily variation that prevailed in this quarter of the globe (148).

            Elsewhere throughout Alaskan shores and waters, the record of Russian

    magnetic data comprises those obtained by various exploreres and travelers

    already recounted in this discussion — Bering, Sarychev, Billings, Gilev,

    Kotzebue, and Lütke. There had been some magnetic work in the Bering Sea

    area by John Rodgers of the Vincennes during the North Pacific Exploring

    Expedition of 1855 (149). With the transfer of sovereignty from Russia to

    the United States in 1867, the exploration and survey of the coasts of Alaska

    became the responsibility of the U.S. Coast and Geodetic Survey. In that

    year a reconnaisance by the party of G. F. Davidson (150) marked the

    inception of this formidable task. A. T. Mosman of Davidson’s party made

    magnetic observations at the Sitka observatory (which was still operating

    as a meteorological station). He also observed on Kodiak Island, and at

    Dutch Harbor in the Aleutians. Two years later, Davidson obtained new

    data during an eclipse expedition (151) to Kohklux (Elukwan), near Skagway.

            This beginning was vigorously follo w ed up by W. H. Dall and Marcus Baker,

    who in 1873, 1874, and 1880 made observations (152) extending throughout the

    021      |      Vol_I-0774                                                                                                                  
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    Aleutian Islands and up the coast beyond Bering Strait to Point Barrow,

    where Maguire of the Plover had spent two winters during the Franklin

    search. The 1880 work was done on a storm-wracked cruise of the steamer

    Yukon , which narrowly escaped destruction. This cruise yielded large

    corrections to the previously accepted magnetic declinations and to the

    longitudes as well, and led to the production of the first isogonic chart

    of the territory having a valid observational foundation. Some of the data

    in southeast Alaska were obtained during a boat journey from Sitka to the

    Chilkat River. Some data for the arctic coast between the Firth River

    and Kotzebue Sound were obtained in 1889 by C. H. Stockton, a naval officer

    of the U.S.S. Thetis (152 a ).

            Europe and the Northeast Passage . With British and American talents

    engaged in the Franklin search and cognate explorations, the interest of other

    nations pressed developments in the European sector of the Arctic. Several

    magnetic stations by K. Chydenius were included in the work of the

    Nordenskiöld (153) expedition of 1861 along the northern coast of West

    Spitsbergen. The Nordenskiöld expedition of 1868 in the Sophie (154)

    was likewise productive of magnetic data for this area, the work of K. S.

    Lemström and several other members of the expedition. The first German

    North Polar Expedition, led by K. Koldewey (155), visited the same locality

    in 1868 and brought back declination values for 50 points along the track

    of the Germania . The Second German North Polar Expedition of Koldewey and

    Hegemann (1 65 56 ) yielded data by C. N. J. Börgen and Ralph Copeland for ✓ cf. orig. p. 27

    Sabine Island and a nearby part of the east coast of Greenland. This was

    the first such expedition to make use of an earth inductor or dynamoelectric

    instrument in the measurement of dip.



    022      |      Vol_I-0775                                                                                                                  
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            Some magnetic data accrued during hydrographic surveys of Novaya Zemlya

    about 1870, such as those of E. Carlsen and Edward H. Johannesen (157).

    The magnetic survey of northern Europe included a river, lake, and ocean

    tour made in 1870 by Ivan Belavenetz in connection with the Varyag expe–

    dition of Grand Duke Alexis (158). An important advance was accomplished

    by the Russian and Siberian survey made in 1873-74 by F. F. Miller; some

    64 stations were occupied, many of them in the arctic zone (159).

            The Austro-Hungarian expedition of 1872-74, le t d by Weyprecht and

    Payer (160), was equipped with the latest type of instruments for observing

    the fluctuations of the magnetic elements. These variometers, of Lamont’s

    design, enabled three elements to be read in rapid succession, using small

    magnets having relatively short periods of oscillation. This markedly

    enhanced the significance of the results, in view of the almost continual

    motion of the magnets characteristic of such observations in the Arctic.

    This apparatus was set up in a snow hut soon after the Tegetthoff , in its

    its erratic northward drift, had come to rest at Wilczek Island in the Franz

    Jose ph f Archipelago. The readings were made on a notably intensive schedule

    for more than three months, and were among the first to provide virtually

    simultaneous values of three magnetic elements, being also the earliest

    magnetic data of any sort for that remote region. The data are credited

    to Karl Weyprecht, Gustav Brosch, and Ed. Orel. They include absolute

    values both there and at various points traversed during the northward drift.

            The Swedish Polar Expedition of 1872-73 under Nordenskiöld (161)

    produced another important body of variation data, applying in this case

    to the winter station at Mossel Bay, near the northern tip of West Spitsbergen.

    The observers were August Wijkander and Louis Palander. New data for Norwegian

    023      |      Vol_I-0776                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    coastal ports as far as Vardö, and sea observations in the Norwegian and

    Greenland Seas, resulted from the North Atlantic hydrographic cruises (162)

    of the Norwegian vessel Vöringen during 1876, 1877, and 1878. The magnetic

    data are due to C. Will s e . The magnetic elements were observed by H. M.

    Speelman, L. B. Koolemans Beynen, L. A. H. Lamie, C. J. G. de Booij, and

    J. H. Calmeijer in the cruises of the William Barents in 1878-81 to Bear

    Island and Amsterdam Island (Svalbard) and Novaya Zemlya (162a). Hydro–

    graphic operations in the Bering Strait area by M. S. Onatsevich (163)

    likewise yielded magnetic data during this period.

            The celebrated voyage of the Vega in 1878-80 under Palander and

    Nordenskiöld (164), the first to achieve the Northeast Passage, yielded

    magnetic data for many points along the route, including a three-month

    series of variation data for Pitleka i , the wintering station where the

    expedition was detained when just short of Bering Strait. The observer

    was A. P. Hovgaard. The American expedition of George W. De Long in the

    Jeannette (165) in 1879-82, despite its tragic outcome, yielded new

    magnetic data along with its valuable geographic discoveries in the East

    Siberian Sea.

            Data for Wrangel Island were obtained in 1881 by C.L. Hooper of

    the Corwin (166) and by R. M. Berry and G. R. Putnam of the Rodgers (167),

    a relief ship sent to search for De Long.

            The International Polar Expedition . The Franklin search expeditions

    and several European expeditions had, by 1875, contributed a number of

    series of variation observations — that is, detailed readings on a pro–

    tracted hourly schedule, or some comparable means of keeping track of the

    transient fluctuations. There were enough data of this sort to demonstrate

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    EA-I. Knapp: Geomagneti c sm

    the challenging complexity of the daily variation pattern in the Arctic,

    and the extreme difficulty of separating the fortuitous fluctuations from

    those which might be expected to show regularity from day to day and from

    year to year. The prevalence of irregular disturbances in high latitudes

    was recognized, though it was not clear just how they were interrelated in

    different sectors.

            The factors that retarded progress in these topics were clearly dis–

    cerned by Karl Weyprecht, the Austrian naval officer, who supervised the

    scientific work and the land explorations of the Tegetthoff expedition.

    Though he secured some valued results, yet he was dissatisfied with what

    any isolated expedition might hope to achieve. He argued cogently that

    concerted efforts in all sectors of the Arctic would accomplish more in

    a scientific sense than would any number of consecutive, independent

    expeditions. His proposals met with the ready concurrence of meteorolo–

    gists and magneticians of other nations, and culminated in the establishment

    of the International Polar Commission to promote a full-year program of

    intensive arctic investigation, with meteorology and geomagnetism as the

    chief topics of study. The participating nations undertook to send expe–

    ditions to different parts of the Arctic, while the Commission secured

    agreement on uniform minimum standards for the observing program, and

    supervised the publication of the results.

            The 13-month period beginning on August 1, 1882, was agreed upon for

    the occupation of all the stations and was designated as the “International

    Polar Year.” Greely’s Polar Handbook (11), Chapter 16, gives a good account

    of the twelve expeditions, their original objectives, and their immediate

    accomplishments. Neumayer (180) gives a somewhat more extended account.

    025      |      Vol_I-0778                                                                                                                  
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    Summarized results in a form useful for reducing the data of subsequent

    expeditions to mean of day have appeared several times, for example, in

    an account by Fleming (218). Table I will serve for tracing the published

    output of each group and it also gives a few details of general interest.

    TABLE I.
    Participating

    country
    Leader Locality

    of work
    Station

    occupied
    Austria-Hungary E. von Wohlgemuth Norwegian Sea Jan Mayen (168)
    Denmark A. F. W. Paulsen SW. Greenland Godthaab (169)
    Germany W. Giese Cumberland Sound,

    Baffin Island
    Kingua Fjord (170)
    United States A. W. Greely NE. Ellesmere Island Fort Conger (171)
    Great Britain H. P. Dawson Great Slave Lake Fort Rae (172)
    United States P. H. Ray Point Barrow Ooglaamie (173)
    Russia N. Jürgens Lena Delta Sagastyr (174)
    Netherlands M. Snellen Kara Sea (175)
    Russia K. P. Andrejeff Novaya Zemlya Karmakuly Bay (176)
    Finland K. S. Lemström Arctic Finland Sodankylä and

    Kultala (177)
    Norway A. S. Steen North Cape Bossekop (178)
    Sweden N. Ekholm Ice Fjord, Svalbard Cape Thordsen (179)

            The scientific gains that accrued from the International Polar Year

    program in terrestrial magnetism were important and lasting. It was possible

    at last to correlate the fluctuations occurring simultaneously in different

    parts of the Arctic, and to work out in some degree the patterns which governed

    them, although the coverage was not sufficient to develop the details of the

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    patterns. One Two such stud y ies were though was made respectively , by G. Lüdeling of the Potsdam Observatory

    (181) . and by H. van Bemmelen of the Netherlands (181a).

            Though the International Polar Expedition as a whole was not primarily

    devoted to geographical exploration, some of the separate units did carry

    out important sledging trips, one of which (based at Fort Conger) reached

    a higher latitude than had ever before been attained. Through some mute

    conspiracy of error and misfortune, the Greely expedition was brought to

    disaster in its retreat from the Arctic. Nevertheless, the seven survivors

    managed to preserve the priceless records of the scientific work. Mention

    should also be made of some scattered magnetic observations (171a) made in

    Baffin Bay by officers of four vessels that collaborated in the relief of

    the Greely expedition in 1884 — F. H. Crosby of the Bear , U. Sebres of the

    Thetis , E. S. Prince of the Yantic , and C. J. Badger of the Alert .

            While not simultaneous with the international program, a somewhat

    similar expedition under A. R. Gordon conducted observations for a year

    at Stupart Bay Station on Hudson Strait, in continuation of the Fort Rae

    work and using the same instruments (16).

            Some European Leaders . The thorough Danish explorations of the shores

    and mountains of Greenland are well reported in the many volumes of

    Meddelelser on Grönland . Magnetic work has not been neglected in these

    surveys. To illustrate the scope of the task, a few examples will be given.

    Steenstrup and Hammer determined the coordinates and the declination at

    about 80 stations in the vicinity of Umanak Fjord in 1878-80 (182).

    G. Holm’s explorations in 1884-85 yielded protracted declination data at

    the headquarters (Nanortalik) west of Cape Farewell (182a). Farther to

    the north, F. Petersen investigated the vicinity of Egedesminde, Disko

    Bay (183), in 1895-96.



    027      |      Vol_I-0780                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            Data for Jan Mayen and Spitsbergen were obtained by A. Exelmans and

    others on the voyage of La Manche in 1892 (184).

            One of the benefits of the Polar Year work was to impel broader

    recognition of the magnitude and importance attached to the task of obtain–

    ing intensive magnetic data on arctic expeditions generally. Extended

    series of variation data became the rule. Thus, C. H. Ryder made extensive

    observations in 1891-92 on the eastern coast of Greenland, at Scoresby

    Sound (185) not far from Sabine’s Pendulum Island, while another series of

    data were obtained by H. Stade of the Greenland expedition of 1891-93, at

    Umanak Fjord on the west coast (186). At the same time, magnetic surveys

    in the regional sense were not neglected. A contribution to the magnetic

    survey of Siberia was made by E. Stelling in 1888 (187), while E. Shileiko,

    as a participant in E. von Toll’s expedition of 1893, occupied 37 stations

    in a region bordering on the Laptev Sea — nine of them in the New Siberian

    Islands (245).

            With respect to territorial coverage, one of the most significant and

    valuable contributions to arctic geomagnetism was that of the celebrated

    Nansen drift expedition of 1893-96, when the Fram was deliberately pushed

    into the ice near the New Siberian Islands and carried right across the polar

    sea, traversing a region never before approached (188); Lieutenant Scott-Hansen

    conducted the magnetic work with unflagging zeal throughout the long period

    of drift. Two circumstances conferred special significance on the work —

    first, the observations were made on the ice, well clear of the influence of

    the ship, and second, the path of drift lay over the very deep water of the

    inner Arctic, entirely beyond the continental shelf and hence largely immune

    to the intensive microstructure of the earth’s magnetism that so often tends

    028      |      Vol_I-0781                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    to confuse and obscure the general distribution. Thus, the westward track

    crossed the meridian of Franz Josef Land about 300 miles to the north of that

    archipelago, at more than 85° N. latitude.

            The U.S. Coast and Geodetic Survey . Following the acquisition of Alaska

    by the United States, there had been an expansion of government mapping

    activities and related functions, not only in Alaska but in other circum–

    polar and outlying areas as well. In due course, the magnetic duties of

    the U.S. Coast and Geodetic Survey partook of this activity. In the interior

    of Alaska, important work was done along the Yukon and Porcupine rivers in

    the period 1889-91. A station called Camp Colonna, on the latter stream near

    the Canadian boundary, was the site of a strenuous program of magnetic work

    by J. H. Turner and H. M. W. Edmonds, including a 24-hour series of readings

    of declination spaced five minutes apart and repeated once a week for nearly

    seven months (189). With J. E. McGrath, this group also obtained extended

    data at Camp Davidson on the Yukon, and made isolated determinations at two

    stations on the Firth River and finally at St. Michael and at Dutch Harbor

    (190). During 1892-94, McGrath, Turner, and others observed at the repeat

    stations of Sitka and Port Mulgrave, and at many coastal points distributed

    throughout southeast Alaska (191). One more station was contributed by

    Harry Fielding Reid, who in 1890 led an e s x pedition to Glacier Bay (192).

            Owen B. French and George R. Putnam of the Coast and Geodetic Survey

    were detailed to participate, respectively, in the Wellman expedition to

    Svalbard in 1894 and in A. E. Burton’s division of the Sixth Peary

    Expedition to Smith Sound in 1896. French observed declination on Danes

    Island and at four stations along the north coast of Northeast Land (194),

    whereas Putnam made complete magnetic observations at eight stations

    029      |      Vol_I-0782                                                                                                                  
    EA-I. Knapp: Geomagnetism

    distributed between Halifax, Nova Scotia, and Umanak, on Baffin Bay (195).

    Putnam, who in 1881 had accompanied Berry to Wrangel Island, revisited

    the Bering Sea area in 1897 and made an examination of local irregularity

    in the Pribilof Islands (196).

            These activities led up to the establishment in 1901-1902 of the five

    permanent magnetic observatories of the Coast and Geodetic Survey, utilizing

    the latest developments in technique and instrumentation (197). One of

    these observatories was set up at Sitka, near the old Russian blockhouse.

    This is today perhaps the oldest of all magnetic observatories situated

    in high-latitude outposts. From its inception the Sitka observatory employed

    photographic recording in preference to the tedious eye-reading procedures

    so long practiced. (Continuous photographic recording had been in use at

    central observatories for many years, but the photographic processing had

    presented formidable obstacles to remote field use until suitable actinic

    materials were generally available.) The Sitka observatory was erected and

    for several years maintained by H. M. W. Edmonds, who had previously done

    magnetic work by the old method on the Porcupine River, as noted above.

            The Expeditions Continue; Birkeland and Amundsen . The expedition (198)

    led by Otto Sverdrup in the Fram in 1898-1902 was provided with the same

    instruments earlier used by Scott-Hansen in the ice drift of the Fram . The

    magnetic elements were determined several times at each of the four wintering

    stations, although the intruments did not prove to be so well adapted to the

    actual region of Sverdrup’s work in Smith and Jones sounds as they would have

    been on the projected cruise round the north coast of Greenland. Because of

    the reduced horizontal intensity encountered in Jones Sound, it was found

    necessary to make a special long deflection bar so that the customary deflec–

    tions at two distances might be obtained. The observers were V. Baumann and

    G. Isachsen.



    030      |      Vol_I-0783                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            The Russian-Swedish expedition to Svalbard (199) for the purpose of

    measuring an arc of a meridian was equipped for magnetic work as well.

    About 40 stations were occupied in 1898-99, and a short series of varia–

    tion readings was obtained at Treuenberg Bay for both declination and

    horizontal intensity. The voyage of O. Bauendshl in the Matador yielded

    data for a station on Danes Island (201) in 1901. The two expeditions

    (1898-99) of A. G. Nathorst (202; 203) yielded some new data for Svalbard,

    Jan Mayen, and the eastern coast of Greenland (King Oscar Fjord to Wollaston

    Foreland). Farther down the coast, the Amdrup expedition (204) was simul–

    taneously engaged in surveys in the latitudes of Angmagssalik and the

    Arctic Circle, during which magnetic date were obtained. This work in–

    cluded a determination of the daily variation of declination. R. E. Peary

    (205) obtained some values of the declination in the vicinity of Cape

    Washington on the north coast of Greenland, during his memorable explorations

    of 1900-1902. Cagni determined the magnetic elements repeatedly at Teplitz

    Bay, Franz Josef Land, during the expedition (206) of the Duke of the

    Abruzzi in 1899-1900.

            In 1895-96, Morache and Schwerer of a French mission magn e é tique (209) ✓ accent

    obtained data for Iceland and for the coast of Norway as far as Hammerfest.

    This was part of a concerted series of voyages to many lands for determining

    magnetic secular change. Steen visited a chain of 16 stations in Norway

    extending as far as Hammerfest, during the summer of 1902 (207). Some data

    were obtained in 1902 by a Russian hydrographic expedition to the Kara Sea

    and the White Sea (208). Hourly values of the declination were determined

    at the two wintering stations of the Zarya expedition of E. von Toll (245)

    in 1900-1903 — one at Colin Archer Harbor on the Taimyr Peninsula, the

    other at Seal Bay on the west coast of Kotelny, one of the New Siberian Islands.



    031      |      Vol_I-0784                                                                                                                  
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            In 1902-1903 there was an important coordinated study (210) of arctic

    magnetic and auroral phenomena under the direction of Kristian Birkeland of

    Norway. Four stations were set up and operated as magnetic and auroral

    observatories; these were: Kaafjord, near Hammerfest; Matochkin Shar, a

    station at the western end of the strait which bisects Novaya Zemlya;

    Axelöen, on Bell Sound, Svalbard; and Dyrafjord, Iceland. Through the

    intensive study of these data in conjunction with the results obtained 20 years

    earlier at the International Polar Year stations, Birkeland was able to develop

    some far-reaching theories at the nature of magnetic storms and the aurora.

            Roald Amundsen’s expedition in the Gjöa (216) was motivated by the de–

    clared objective of investigating the region around the North Magnetic Pole.

    Though prevented from carrying out in full his plan of a comprehensive mag–

    netic survey, Amundsen was able to make determinations at several points near

    the Pole and, most important, to operate a magnetograph with photographic

    registration for a period of 23 months at Gj o ö a Haven, the headquarters on

    the southeast coast of King William Island. During the expedition’s third

    winter (1905-1906), the same instruments were operated for five months at

    King Point, on Mackenzie Bay, Beaufort Sea. Amundsen’s work at Gj o ö a Haven

    showed that the Magnetic Pole was still about where Ross had fixed it (though

    the precise interpretation to be placed upon data for this region must always

    offer some vexing problems). His voyage was even more acclaimed as the first

    to negotiate the long-sought Northwest Passage in its entire l t y by means of

    a single craft — the celebrated little sloop Gj o ö a.

            The Ziegler expedition of 1903-1905 under Anthony Fiala (218) reached

    Teplitz Bay, Franz Josef Land, where a strenuous program of eye readings of

    magnetic elements was kept up from October 1903 to June 1904. In 1905,

    032      |      Vol_I-0785                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    similar readings were made for a five-week period on Alger Island. The

    scientific work was under the direction of William James Peters, who had

    previously been engaged in explorations for the U.S. Geological Survey in

    arctic Alaska.

            Systematic coverage of the Barren Lands of northern Canada dates back

    to 1896 and 1900. In the latter year, J. W. Tyrrell of the Department of

    the Interior made surveys of the region of the Thelon Game Sanctuary north–

    east of Great Slave Lake (219). The explorations of A. H. Harrison (219a)

    in the Mackenzie Delta and on Herschel Island, in 1905, yielded 23 observa–

    tions of declination obtained by means of a prismatic compass. The explora–

    tions of J. E. Bernier in the Arctic in 1908-1909 were productive of new

    magnetic data for the region of Barrow Strait and Melville Sound (220).

    The observer was W. E. W. Jackson.

            In 1908, an observer of the Carnegie Institution of Washington, C. C.

    Craft, was enabled to obtain magnetic observations at several stations along

    the shores of Baffin Island and West Greenland through the facilities of the

    Peary Roosevelt expedition (221). At three of his stations, daily variation

    was observed.

            We come now to the epic Denmark Denmark expedition of 1906-1908 to northeast

    Greenland. Accomplishing their primary mission of filling in the blank

    area below Peary Land, leader L. Mylius-Erichsen and two companions, as will

    be recalled, perished after misjudging the point of no return. Magnetic

    work received special attention under meteorologist Alfred Wegener, who with

    several associates secured monthly values of the magnetic elements and

    continuous registrations of declination at the wintering station on Dove

    Bay, as well as secular-change data on Sabine Island (221a).

            The 1907 expedition of A. D. Gerlache de Gomery (222) in the Belgica

    produced data on the magnetic elements in the Barents and Kara seas. The

    observer was C. Rachlew. In 1910, declination was observed in Ice Fjord,

    Svalbard, by E. Pr y zybyllok of the Wilhelm Filchner expedition (223).

            Data for the coast of Novaya Zemlya and for the Franz Jose ph f Archi–

    pelago were obtained by V. J. Wiese of the St. Phoca expedition (224) of

    1912-14, led by G. Sedov who perished at Rudolf Island. In the opposite

    032a      |      Vol_I-0786                                                                                                                  
    EA-I. David G. Knapp: Arctic Aspects of Geomagnetism



    033      |      Vol_I-0787                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    arc of the Russian arctic domain, declinations were determined, in 1909,

    at 22 stations along the shore of the East Siberian Sea, by E. Weber and

    E. Skvortsov (245), while magnetic work done by the hydrographic expedi–

    tion of 1911 included observations by Lohman of the Vaigach at Wrangel

    Island and by L. W. Sakharov of the Taimyr on the nearby Chukotsk Peninsula

    (225).

            The s S wiss expedition of 1912-13 across the Greenland icecap (226)

    obtained observations of declination and inclination at about 50 stations

    between Godhavn and Angmagssalik. The leader was Alfred de Quervain and

    the observer Paul-Louis Mercanton.

            The Canadian Arctic Expedition (227) of 1913-18 under Vilhjalmur

    Stefansson observed declination at 26 points in the region north of Melville

    Sound during 1915-17, providing marked improvement in the magnetic charts

    with respect to this area.

            A new order of accuracy was brought to ocean magnetic work with the

    construction of the Carnegie , the nonmagnetic survey vessel of the Carnegie

    Institution of Washington. On the third of her seven cruises (228), this

    vessel, under the command of J. P. Ault, sailed into the Greenland Sea in

    1914 to the latitude of 79°52′ N., permitting frequent observations of all

    the magnetic elements. Similar data for the North Pacific Ocean and part of

    the Bering Sea were obtained in 1915-16, on her fourth cruise (228a).

            The magnetic survey of arctic Russia and western Siberia was considerably

    advanced by field work done in 1918-21, reported by Roze (229). A total of

    52 stations were occupied. One station near Cape Cherny was the site of

    protracted work in 1921, reported by Zhongolovich (231). Another important

    series of field observations was that obtained by J. Keränen in northern

    Finland beginning in 1910 (230).



    034      |      Vol_I-0788                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            In 1918, one of the most protracted of arctic expeditions began with

    the departure of Roald Amundsen and H. U. Sverdrup in the Maud (232).

    This small group was well equipped for magnetic work and succeeded in ob–

    taining valuable results at numerous stations in the arctic coastal regions

    of the U.S.S.R. in the course of their negotiation of the Northeast Passage

    (1918-21). After repairs at Seattle and various changes in equipment, the

    vessel was taken back through Bering Strait and into the ice in 1922, drift–

    ing for two years to a point north of the New Siberian Islands. Valuable

    data were obtained during this drift, including clear evidence of marked

    local irregularity at two points of the track. A declinometer with photo–

    graphic registration was operated at Cape Chelyuskin for ten months beginning

    in October 1918, and at Four Pillar Island for nearly six months beginning in

    December 1924. This expedition was the occasion for an effort on the part

    of Norwegian scientists to promote the establishment of an international net

    of recording stations (233), and in this respect was a precursor of the

    Second International Polar Year.

            In 1920, considerable magnetic work was done by the relief expedition

    of O. Sverdrup and L. Breitfuss in the icebreaker Sviatogor to the Barents

    and Kara seas, and likewise by the cruise of the Taimyr to the same area (234).

            During the summer of 1923, several declinations were observed west of

    Baffin Bay, on Baffin and Ellesmere Islands, by F. D. Henderson of the

    Canadian expedition (235) on the Arctic .

            Noteworthy contributions to geomagnetism resulted from the two expeditions

    of Donald B. MacMillan in the Bowdoin. In each instance, a complete magneto–

    graph was operated during the winter’s stay — at Bowdoin Harbour (236), near

    Cape Dorset on the Foxe Peninsula of Baffin Island, for six months beginning

    035      |      Vol_I-0789                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    in November 1922, and at Refuge Harbor (237) near Etah, on Smith Sound, for

    eight months beginning in October 1923. On both occasions, a number of field

    stations were also occupied. The observers were G. Dawson Howell and, repre–

    senting the Carnegie Institution of Washington, R. H. Goddard. Additional

    data were obtained at five stations in Greenland and two in Labrador by

    Benjamin H. Rigg of the U.S. Coast and Geodetic Survey, as a participant in

    the 1925 MacMillan-Byrd expedition (238).

            In 1929, P. L. Mercanton of the Pourquoi s Pas ? (239) obtained values

    of dip and declination at several stations in Iceland and one on Jan Mayen.

            Some data were obtained in Svalbard by the 1923 and 1924 Oxford Univer–

    sity expeditions (240; 241) led by F. C. Binney. The declination and hori–

    zontal intensity were observed with a magnetometer at several points in

    Svalbard by R. v. d. R. Wooley of the Cambridge expedition (242) of 1927.

    At Camp Lee on Edge Island, a series of half-hourly readings determined the

    daily variation of declination.

            An interesting variation on usual arctic expeditions was that of Sir

    Hubert Wilkins in the submarine Nautilus in 1931 (242a). Data were obtained

    at two stations by F. M. Soule.

            Errors in extant magnetic charts in the region south of the Franz Jose ph f

    Archipelago were noted by P. Collinder of the Björnöy expedition (243) of

    1929. The study of secular change in Soviet territory was advancing steadily

    in this period. Summaries by Malinin (244) and Roze (245) are of interest.

            Aircraft Expeditions . The intriguing possibilities of obtaining magnetic

    data by means of aircraft received their earliest recognition in the pioneering

    arctic flights. Thus, in 1925 Riiser-Larsen with Amundsen and Ellsworth (248)

    brought back data for a point never before visited, near the North Pole, while

    036      |      Vol_I-0790                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    the same men, with Nobile, Malmgren, and others, noted compass data on the

    flight of the Norge in the following year, blazing a path across the polar

    basin from Spitsbergen to Teller, Alaska (249). Two years later a flight

    in the opposite direction was made by Sir Hubert Wilkins; the report on this

    flight is a valuable study of the unique navigational problems of such a

    course (250). The year 1928 also witnessed another project to fly an airship

    out over the polar basin; Umberto Nobile commanded the Italia , which was

    equipped for, and accomplished, significant magnetic work. A valued paper

    on arctic magnetic observing was prepared by Palasso (251). Data obtained

    included some horizontal intensity values at latitudes as high as 81°15′ N.

    However, the craft was wrecked and the expedition was the occasion of much

    random and uncoordinated searching, giving rise to another tragedy in the

    loss of Roald Amundsen. One of the searching groups (252) succeeded in

    obtaining some additional magnetic data for the Svalbard area. The outstand–

    ing achievement in obtaining comprehensive magnetic data in the Arctic by

    air is credited to the flight of the Graf Zeppelin in 1931 over the Barents

    Sea (253). The magnetic observer was Gustaf Ljungdahl.

            Canadian Government Work . The Dominion Observatory at Ottawa has been

    chiefly responsible for the high standing and significance of arctic magnetic

    data in the Canadian sector in recent years. In 1922-23, observations were

    made along the Mackenzie River by C. A. French (255). In 1928, their observer,

    R. G. Madill, was attached to the Hudson Strait Expedition (256) and obtained

    data for Hudson Bay and Strait and for points along the northern reaches of

    Baffin Island. In a similar way, data were obtained in 1934 and 1937 by

    observers who accompanied the Nascopie and the Fort Severn , vessels of the

    Hudson’s Bay Company on the Eastern Arctic Patrol.



    037      |      Vol_I-0791                                                                                                                  
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            Magnetic Observatories and the Second Polar Year . The scientific

    significance and practical value of magnetic observatory work is such that

    nearly every advanced nation is engaged in this activity (257). Special

    importance characterizes the observations in arctic and subarctic regions,

    on account of the peculiarities of the overhead current patterns in these

    high latitudes. The Dominion of Canada has had an observatory since 1916

    at Meanook, near the bend of the Athabaska River, north of Edmonton. The

    Danish Meteorological Institute has maintained an observatory at Godhavn,

    Greenland, since 1926. Soviet scientists have set up several arctic magnetic

    observatories (258) on a permanent basis — the earliest were Matochkin Shar

    (Novaya Zemlya) in 1923 and Bay Tikhaya (Hooker Island, Franz Jose ph f Land)

    in 1931. The Hooker Island station has the distinction of being the most

    northerly permanent magnetic observatory, in latitude 80°20′ N. A valuable

    series of data for nearby points (258a) was obtained in 1934-36. Finland

    has had an arctic observatory at Sodankylä since 1914. Numerous other

    observatories in northern Europe contribute to the understanding of polar

    phenomena, though situated well below the Arctic Circle. One of the important

    functions of the observatories is to provide knowledge of the secular changes

    more accurate and complete than can be obtained in any other way. Annual mean

    values are derived for this application. The best-collected sources of such

    means are the lists by Bock and Schumann (3) and by Fleming and Scott (10).

    For general information, abbreviated lists have also been published, such as

    that by Chapman and Bartels (7) and another in the Smithsonian Physical Tables.

    (References to the lists of mean values are not repeated here in relation to

    individual stations. However, those mentioned above are quite comprehensive.)



    038      |      Vol_I-0792                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            With the growth of the network of observatories using photographic

    registration, and the gradual refinement of their apparatus, many signifi–

    cant facts about the transient fluctuations came to light. One of the

    revealing phenomena eliciting much study has been that of micropulsations

    or short, infrequent series of sinusoidal oscillations of the magnetic

    elements, with a period of a fraction of a minute. The complexities of

    magnetic storms and the aurora (259) always remain an intriguing field,

    and the pursuit of these and other topics led to the proposal for a Second

    or Jubilee International Polar Year, which was carried out in 1932-33.

    This program differed from its prototype of fifty years earlier in that

    photographic registration was used throughout, and the number of stations

    was considerably greater. Furthermore, many permanent observatories (not in

    high latitudes alone) cooperated by installing specially constructed rapid-run

    instruments in order to obtain more detailed records of the interesting fine

    structure of the transient fluctuations.

            The complete story of the Second International Polar Year remains to be

    written; however, several general references (260) will be helpful in showing

    some of the accomplishments of the undertaking. Individual Polar Year stations

    for which published data are known to be extant are given in Table II (in se–

    quence of longitude, westward from the Greenwich meridian).



    039      |      Vol_I-0793                                                                                                                  
    EA-I. Knapp: Geomagnetism

    TABLE II.
    Participating

    country
    Locality

    of work
    Station

    occupied
    Austria Norwegian Sea Jan Mayen (265)
    France E. Greenland Scoresby Sound (268)
    Netherlands SE. Greenland Angmagssalik (269)
    Denmark S. Greenland Julianehaab (270)
    Denmark NW. Greenland Thule (271)
    Canada Hudson Bay Chesterfield Inlet (272)
    Great Britain Great Slave Lake Fort Rae (273)
    United States mid-Alaska College (274)
    United States N. Alaska Point Barrow (275)
    U.S.S.R. Yenisei Gulf Dickson Island (276)
    Finland Barents Coast Petsamo (277)
    Norway Barents Coast Bossekop, etc. (278)
    Poland Svalbard Bear island (279)
    Sweden Svalbard Sveagruval (280)

            Permanent observatories established prior to 1932 in and near the arctic

    zone have already been mentioned; one of them (Sodankylä) represents a station

    of the original International Polar B Y ear. There is as yet no published biblio–

    graphy of the many investigations which have been founded on Polar Year data.

    A few examples may be mentioned by way of illustration, as reflected in papers

    by Vestine and Chapman (281), Hasegawa (282), and Errulat (283).

            Recent Work in Alaska. The basic magnetic survey of the territory of

    Alaska has been steadily carried forward by the United States Coast and Geodetic

    Survey. By far the greatest number of observations comprise those for declina–

    tion made with the compass declinometer or transit magnetometer in connection

    040      |      Vol_I-0794                                                                                                                  
    EA-I. Knap: Geomagnetism

    with the establishment of shore control for the hydrographic work. These

    observations serve to disclose many areas of local irregularity potentially

    dangerous to navigation, and in conjunction with comparable work done along

    the 141st meridian during the survey of the international boundary, they

    are the chief basis for the isogonic charts issued in recent years, though

    not entirely satisfactory for this purpose since they tend to cluster

    about the most frequented harbors of the southeastern part of Alaska; similar

    work has quite recently been extended to the arctic coast line. In some

    interior areas the isogonic chart also benefits from reconnaissance surveys

    by the U.S. Geological Survey and the Corps of Engineers of the U.S. Army (284).

            In the interior, there has been a steady accretion of data on all three

    magnetic elements, held to the high standards required of repeat-station

    work in the Coast and Geodetic Survey. This program has been executed by the

    following observers, each of whom established some new stations and revisited

    some of those marked by his predecessors: J. W. Green (285) in 1908;

    J. W. Green (286) in 1918; J. T. Watkins (288) in 1921; F. P. Ulrich (290)

    in 1928; C. A. George (291) in 1929; E. H. Bramhall (295) in 1939-40;

    N. O. Parker and F. Keller, Jr. (296) in 1944; and M. L. Cleven (297) in 1947.

    For the past ten years these campaigns have been expedited through the use

    of aircraft to travel from station to station, enabling the stations to be

    placed without regard to surface transport, so that northern Alaska is now

    well represented.

            With respect to known magnetic work in the field of exploration geophysics,

    most of the Arctic remains virgin territory, but Alaska is a notable exception.

    In 1939-40, the Territorial Department of Mines carried out surveys of

    certain areas for vertical-intensity anomalies, using a Schmidt balance (292).

    041      |      Vol_I-0795                                                                                                                  
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    More recently, air-borne surveys of northern Alaska were carried out in

    cooperation with the U.S. Naval Petroleum Reserve; this was one of the

    first large projects to employ the war-perfected magnetic air-borns detector

    for geophysical purposes (293).

            At the University of Alaska, near Fairbanks, a temporary magnetic

    observatory was set up in 1941 by the Department of Terrestrial Magnetism

    of the Carnegie Institution of Washington. In 1946, this observatory was

    taken over by the U.S. Coast and Geodetic Survey and the University of Alaska.

    In 1948, a standard observatory of the Survey was established here.

            General Expeditions . In the summer of 1932 a Soviet group sent the

    icebreaker Sibiriakov along the arctic coast of the U.S.R.R. (298). Magnetic

    data were obtained at four stations. Again, the icebreakers Malygin (299) and place low[ ?]

    Sedov (300) obtained some data in the northeastern part of the Kara Sea in

    1934-35. In the latter year, a new series of land magnetic data was obtained

    on the Taimyr Peninsula (301). Surveys along the arctic coast of the U.S.R.R.

    were also in progress in 1936 (302).

            In May 1937, a group of four Soviet observers was flown to a drifting

    station on the ice near the North Pole (307). This intrepid band under

    Ivan Papanin obtained magnetic and other data throughout the path of their

    drift, which led to the waters off Scoresby Sound, in the latitude of Jan

    Mayen. Another but less voluntary drift began the same year when the icebreaker

    Sedov was beset in the ice while conducting hydrographic work near the New

    Siberian Islands. The vessel was carried westward for many months on a

    track even farther north than that of the Fram . Valuable data were obtained

    during a portion of this drift (308).



    042      |      Vol_I-0796                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            Magnetic observations were made on Baffin Island by the Isbjörn

    expedition of J. M. Wordie in 1937 (309). The MacGregor Arctic Expedition

    of 1937-38 (310 ) operated a weather station and complete magnetic observatory

    from October to June at Reindeer Point, near Etah. Observations were made

    by C. J. MacGregor and Roy G. Fitzsimmons. The Louise A. Boyd expedition

    of 1938 obtained new data for northeast Greenland, Jan Mayen, and Parry

    Island (Svalbard). The magnetic work was by J. M. Leroy (311).

            A magnetic survey of Norway was begun in 1938 and completed in 1941 during

    the occupation of the country by Nazi forces — a remarkable example of the

    importance attached to magnetic survey work and of perseverance capable of

    surmounting obstacles (312).

            Except for the area close to the Magnetic Pole and a few other localities,

    the magnetic patterns pertaining to the Canadian Arctic have been largely

    dependent upon old observations, dating back (in some areas) as far as the

    Franklin search. However, through a vigorous program led by the Dominion

    Observatory, with the assistance of cooperating agencies, a great mass of

    new data has been collected since 1941. Special expeditions during this

    period have also contributed materially. F. R. Gracely of the Louise A.

    Boyd expedition of 1941 (313) obtained complete observations at 17 stations

    distributed along both shores of Davis Strait and Baffin Bay, as far as Etah .

    , whereas R. G. Fitzsimmons of the U.S. Air Force, in 1943, obtained similar

    data at 34 stations between Goose Bay, Labrador, and Disko Bay, Greenland

    (313a).
    Joel B. Campbell of the U.S. Coast and Geodetic Survey, detailed to accompany

    “Operation Nanook,” T t he U.S. Navy expedition of 1946, visited several stations

    around Devon Island (297). Cameron Cumming of the Dominion Observatory

    visited eight stations to the north of Barrow Strait and Lancaster Sound in

    1947, and several more in 1948, both times being detailed to accompany U.S.

    Navy expeditions (314). A party headed by Paul H. Serson of the Dominion

    042a      |      Vol_I-0797                                                                                                                  
    EA-I. David G. Knapp: Arctic Aspects of Geomagnetism



    043      |      Vol_I-0798                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    Observatory visited several points in the region of the Magnetic Pole during

    1947, using an R.C.A.F. Canso aircraft based at Cambridge Bay, Victoria

    Island. This work was continued in 1948, embracing several stations on

    Victoria Banks, and Melville Islands. As one result of the work done thus

    far, the Dominion Observatory has adopted a tentative new position of the

    North Magnetic Pole, in the northern part of Prince of Wales Island (20).

    (See also “The Search for the North Magnetic Pole.”)

            Use of the Magnetic Compass in High Latitudes. The well-known sluggish–

    ness of the magnetic compass in the Arctic is but one of several related

    problems stemming from the reduced directive force governing the instrument . (314a).

    In connection with the early voyages, we noted how this arctic deficiency

    tends to magnify the deviation of the compass — the error produced by mag–

    netic material built into the ship or aircraft in which the compass is

    installed. Soviet navigators plying the Siberian seaway have found this

    increase in deviation to be a serious hazard, even in regions where the

    responsiveness of the compass is quite acceptable (315). Reliance upon the

    compass for air navigation in these areas of reduced horizontal intensity

    presents still another hazard in that the transient flucutuations in the

    direction of the magnetic field, generally trifling in low latitudes,

    become here quite severe and frequent. The fortuitous changes in the

    direction of magnetic north may sometimes amount to many degrees in a few

    minutes of time (315). One safeguard is to make provision for comparing

    the readings of compasses with differing characteristics, in order to

    diminish the risk that such disturbances would pass unnoticed.



    044      |      Vol_I-0799                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            The prime requisite for using a magnetic compass of any description

    is that the horizontal intensity shall be strong enough to meet certain

    minimal requirements. These requirements are fixed primarily by the design

    of the compass, but with any given compass the demands become more stringent

    under dynamic conditions. This refers particularly to the violent accelera–

    tions experienced in modern high-speed aircraft, tending to obliterate the

    reference scheme normally provided by the steady downward force of gravity.

    Thus, a compass which shows severe turning errors in a high-speed plane

    operating in a given region might be perfectly satisfactory in the same

    area when used in a low-speed aircraft.

            The experience of Amundsen and others has shown that the usefulness of

    the magnetic compass is not, as sometimes asserted, extinguished by nearness

    to the geographic Pole per se. The horizontal intensity at the geographic

    North Pole is comparable with that in Coronation Gulf or at Baker Lake, both

    places where suitable types of magnetic compass will respond well, and where

    almost any type will find some usefulness. The conventional isogonic chart,

    however, is unsuited for use in the vicinity of the Pole, primarily because,

    by employing the converging meridians as a frame of reference, it injects a

    needless and indeed a spurious complexity in the pattern of magnetic azimuths.

    When the isogonic lines are reconstructed in terms of a reference grid con–

    sisting of straight lines drawn parallel to some particular (say the Greenwich)

    meridian, they assume a less intricate pattern and become quite manageable

    for air navigation.

            Difficulties of Polar Magnetic Observations . The success of an arctic

    expedition from the magnetician’s viewpoint is directly dependent u l p on the

    kind and quality of the instruments used, but even more upon the degree of

    045      |      Vol_I-0800                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    competence of the observers. Instruments for magnetic work, when correctly

    manipulated (14) by well-trained observers, take rank among the most sensi–

    tive and accurate measuring implements devised by man.

            Assuming that instruments of requisite grade have been provided and

    that the persons using them are qualified, there remain several special

    problems arising from the physical conditions encountered — some of them

    seemingly trivial but nonetheless important. Control knobs that require

    intricate finger manipulation should be sheathed in plastic for use at low

    temperatures. Lubricated bearings should be treated with lubricants suit–

    able for the lowest expected temperatures.

            The instruments provided should be suitable for the actual range of

    values of the magnetic elements likely to be encountered. The reduced values

    of horizontal intensity in a portion of the Arctic are a potential source of

    trouble with all instruments having a horizontal magnet. Compasses and other

    pivot instruments become sluggish and finally inoperative in an area the

    extent of which depends inversely on the perfection of the pivots and jewels.

    The magnetic meridian can nearly always be determined with a theodolite

    magnetometer, although the complete removal of torsion from the suspending

    fiber may be difficult, with some resulting error, and the observations will

    take longer on account of the increased period of oscillation. In using this

    instrument to measure horizontal intensity, both the oscillations and the de–

    flections may require modification — the former by using a smaller number

    of swings, the latter by providing a special bar to hold the deflector at

    a greater distance. The la Cour QHM (quartz-fiber hori s z ontal magnetometer)

    may require a special fiber of reduced cross section.



    046      |      Vol_I-0801                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

            The difficulty of measuring horizontal intensity sometimes leads

    arctic observers to substitute total intensity measurements by Lloyd's

    method, using a dip circle. However, it should be recognized that the

    accuracy with which horizontal intensity can be derived from total inten–

    sity is critically dependent upon the accuracy of the dip measurements.

    It is now well understood that the dip circle is decidedly inferior to the

    inductor inclinometer (earth inductor), and there is no doubt that full

    reliance upon the dip circle leads to horizontal-intensity results having

    a lower order of accuracy than is needed for modern arctic work, in which

    great stress is placed upon horizontal intensity, as will be seen presently.

            With many instruments, the effects of a changing relation between the

    magnetic meridian and the orientation of the instrument call for careful

    consideration. In areas of small horizontal intensity, the magnetic

    meridian may shift appreciably during ordinary transient fluctuations,

    whereas , the whole observing station may be rotated if it is established

    on drifting ice; this effect has been studied by Peters (22). An instru–

    ment especially suited for measuring horizontal intensity on a shifting

    platform is the Bidlingmaier double compass; this device was used on the

    Carnegie and later on the arctic flight of the Graf Zeppelin in 1931 . (316a).

            Instruments permitting direct determination of the sun's magnetic

    azimuth are invaluable for observations on the ice of the polar sea, or

    in any situation where there is no prominent object on the horizon to

    serve as an azimuth mark for the declination measurements.

            A recurrent difficulty in arctic work concerns the identification of

    "repeat" stations for reoccupation. The exact recovery so essential for

    "repeat" work on land may be rendered difficult by the absence of distinguish–

    ing topography or by disturbance of station markers through frost action ,

    047      |      Vol_I-0802                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    lack of protective vegetation, and attendant rapid erosion.

            Another important factor is the frequency and intensity of magnetic

    disturbance arising from overhead electrical phenomena — the effects

    which in their extreme manifestation are described as a magnetic storm.

    These disturbances are especially severe along a belt known as the "auroral

    zone," where auroral activity has a maximum, but they are also apt to be

    troublesome in high latitudes generally (315b). The observer should familiar–

    ize himself with the experience of earlier expeditions in the region to be

    visited, particularly as regards the time of day at which such disturbance

    is most common. For example, in mid-Alaska it is established that magnetic

    activity usually has its maximum around local midnight.

            Different Kinds of Transient Magnetic Fluctuations . The daily varia–

    tion patterns have always been a challenging field of study. See, for

    instance, Maurain's discussion of the Second Polar Year program (263).

    It is now considered that the pattern observed on a given day is a mixture

    of at least two characteristic types in varying proportions. In low lati–

    tudes, the well-known quiet daily variation is predominant most of the

    time. But there is nearly always a slight admixture of an entirely different

    sort of pattern — namely, the disturbance daily variation, which on some

    days becomes an important feature. This patter phenomenon is characterized

    by a heavy concentration along the auroral zone, where it tends to be the

    controlling factor even on ordinary "quiet" days ( 181a; 282).

            The disturbance daily variation is so variable in amplitude from day

    to day that it is difficult to generalize it and establish characteristic

    forms for different conditions, but it is an ever-present element in all

    arctic magnetic work. In addition, there are the irregular, violent

    048      |      Vol_I-0803                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    fluctuations that commonly occur during disturbed periods: the rare

    so-called "giant pulsations" observed particularly in Scandinavia and

    Iceland (316); the more widespread "micropulsations" that are sometimes recorded;

    and the storm-time variation, a s t atistical mean phenomenon which comes out

    of the analysis of many magnetic storms when taken compositely.

            All these transient effects m o i rror the incessant streaming of electrons

    or ions in the earth's upper atmosphere or in the space outside the atmos–

    phere. They are all more frequent and severe in the circumpolar regions

    than in tropical and temperate regions (317). They hamper (but do not nullify)

    our efforts to map the arctic patterns of the permanent magnetic field of

    the earth, and at the same time they constitute a large and rewarding field

    of investigation in themselves, with ramifications extending in several direc–

    tions. For example, the study of radio signal transmission often hinges on

    ionospheric conditions in the Arctic, and these conditions are never com–

    pletely known without having records of the magnetic activity in the area.

    An ionospheric recording station was maintained for eight months in 1942-43

    at Barentsburg, Svalbard, on behalf of the British Admiralty. The program

    of this station, under A. B. Whatman, included approximate registrations of

    the activity fluctuations of vertical magnetic intensity (318).

            The increasing number of permanent magnetic observatories in the Arctic

    speaks eloquently of the importance which this activity has assumed. Two

    recently established observatories are those of Sweden and the U.S.S.R.,

    respectively, at Abisko (near Narvik) and at Tiksi, on the Lena Delta (331).

    Still another one commenced operations at the beginning of 1947 at Thule,

    Greenland (319), while in Canada there are two new observatories — one at

    Baker Lake, not far from the Canadian Polar Year station, Chesterfield Inlet;

    049      |      Vol_I-0804                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    the other at Resolute Bay, Cornwallis Island. The station at Baker Lake

    was established in December 1947, and the one at Resolute Bay in the

    following summer (320). The latest (1949) addition to the observatory net is a station near Point

    Barrow, Alaska, the Barrow Magnetic Observatory, established jointly by the

    U.S. Coast and Geodetic Survey and the U.S. Office of Naval Research (319a).

            Modern Views of Geomagnetism in the Arctic . The patterns formed by

    the distribution of the earth's main field have the character of a smooth

    underlying scheme filtered through a screen that superimposes an intricate

    fine structure of local irregularity. The "screen" is clearly that relatively

    thin fraction of the earth's crust that is cooler than the Curie temperature

    point (321). The seat of the underlying pattern, which might appropriately

    be called the primal geomagnetic field, is not so well established, but the

    scale of its spatial features is such as to permit of a source at a consider–

    able depth, perhaps halfway to the earth's center (322). Thus, the manifest

    demarcation between the two aspects of the field may have real physical

    significance in terms of the action of a superficial distorting and roughen–

    ing layer, modifying the effect of a deep-seated primal field, the latter

    being, according to one suggestion, the product of a profound electrodynamic

    activity in a molten core.

            A vast amount of work is currently devoted to geophysical exploration

    in many parts of the world, a sizable portion being conducted by the magnetic

    method. (This mapping of the magnetic patterns that are produced by the

    "screen" of the earth's crust has been greatly expedited by the use of

    recently developed air-borne equipment.) It is generally considered that

    in most areas few of the magnetic effects aries from geological formations

    lying above the basement complex — that is, the sedimentary rocks are so

    nearly nonmagnetic that they have virtually no influence on the patterns

    usually observed. In places where the basement rocks are near the surface,

    049a      |      Vol_I-0805                                                                                                                  
    EA-I. David G. Knapp: Arctic Aspects of Geomagnetism



    050      |      Vol_I-0806                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    the magnetic field is apt to show intense irregularity on the ground, whereas

    at altitudes accessible to modern aircraft the anomaly patterns become some–

    what less erratic, while largely preserving their striking regional features.

    Few areas are so free from anomaly that the primal field can be directly

    observed, even at maximum altitudes.

            Dismissing from present consideration both the local irregularities and

    the transient fluctuations, let us consider how the magnetic elements are

    distributed in the Arctic, for they do not at all exhibit the radial symmetry

    that was once assumed to prevail. The dip, which throughout the Arctic has

    values greater than 76°, builds up gradually toward a narrow oval of values

    in excess of 88°, stretching out from the lower Back River across the Canadian

    Archipelago and into the Arctic Sea in the direction of the Taimyr Peninsula.

    The vertical intensity does not show any pronounced differentiation, ranging

    for the most part between 0.5 and 0.6 oersted. There are two rather weakly

    developed maxima, which may well be related to the above-mentioned zone of

    high dip; one of them is near the western extremity of Hudson Bay, the other

    in the mountainous area (Vilyuiskte Gory) west of the Lena River, in Siberia.

    However, this element is for our present purposes of subordinate interest and

    significance, in view of the slight differences involved; it is the horizontal

    component that chiefly merits attention.

            It is no easy task to visualize the behavior of horizontal intensity in

    a region where it is subject to such abrupt spatial transformations in both

    direction and magnitude. To resolve this difficulty, we may resort to the

    concept of magnetic potential, a scalar quantity that lends itself admirably

    to this end. Technically, the potential is defined as the quantity whose

    derivative along any direction in space, with respect to distance, is the

    051      |      Vol_I-0807                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    negative of the component of magnetic intensity along that direction. The

    sea-level distribution of magnetic potential over the Arctic might be de–

    picted by a system of equipotential lines. The direction of the magnetic

    horizontal intensity at any place is normal to the equipotential lines, in

    the sense of decreasing potential; and the relative strength of the horizon–

    tal component is denoted by the closeness with which the lines are spaced.

    If the compass really pointed toward a center from all nearby places, the

    equipotential lines would be circles about that center.

            Now, we know that the horizontal intensity displays a highly elongated

    pattern in the Arctic (19). (This would be a necessary consequence of the

    elongated dip pattern in the absence of marked features of vertical intensity,

    and is a well-established feature in any event.) Chapman has shown that the

    equipotential lines must partake of the same property (323). He found that

    they would be somewhat less elongated than the horizontal-intensity iso-lines.

    Going outward, the eccentricity of the ellipses decreases as they grow

    larger. The mind immediately inquires as to the probable nature of the

    distribution in the core of the pattern. Lacking direct evidence on this

    point, speculation may be instructive.

            If the eccentricity were uniform for the smaller curves, we should have

    an elliptic focus centered at the Magnetic Pole. But we know that this is not

    the case, because the Ross-Amundsen pole is far to the south of the center of

    the pattern (20). ( Recent observations indicate that it has shifted somewhat

    to the north, but not enough to affect the present argument.) The thought

    immediately suggests itself that, instead of a single concentric nest of

    diminishing ellipses, the equipotential curves may show a figure-eight pattern,

    with two distinct poles. Such a pattern would also have a nodal point in the

    052      |      Vol_I-0808                                                                                                                  
    EA-I. Knapp: Geomagneti c sm

    center, where the horizontal intensity vanishes and the dip needle stands

    vertic le al — a false pole, however, since the neighboring equipotential

    curves do not close about it, and the magnetic meridian (324) curves (the

    curves which follow the compass direction) do not converge upon it. Instead,

    the latter form a pattern such as would appear at a street intersection if

    all the traffic made right turns.

            On this view the Ross pole would have its counterpart near the opposite

    extremity of the elongated pattern, in the remotest zone of the arctic basin.

    Observations in that area are too sparse for present disposal of the question,

    but it is significant that both the drift of the Sedov in 1938 (308) and the

    flight of the Soviet aircraft N-169 in 1941 yielded some data which supported

    Veinberg's deduction that a second pole existed in this area (325). Another

    pertinent group of data is that afforded by the 1945 flight of the British

    Lancaster Aries from Whitehorse, Yukon Territory, to Shawbury, England (328).

            It is apparent that a great deal of work remains to be done before the

    complex magnetic patterns of the Arctic are fully determined. The latest

    contribution toward the problem is represented by compass data obtained by

    the U.S. Air Force (329), but one cannot rely entirely on compass data for

    such an area, particularly in view of the difficulties imposed by severe

    deviation troubles due to the greatly reduced horizontal intensity. Only

    by carefully controlled measurements of the horizontal intensity itself can

    the patterns be finally worked out.

            If we now consider the continual changes in the earth's magnetism it

    will be clear that the polar pattern — whatever its real configuration —

    must partake of those changes by undergoing various kinds of motion over

    the region; it will never be entirely stationary. The motion can be deduced

    053      |      Vol_I-0809                                                                                                                  
    EA-I Knapp: Geomagnetism

    if the changes of the field are known. For the ordinary quiet daily

    variation, Schmidt and Nippoldt predicted (and Wasserfall confirmed) that

    the motion takes the form of an ellipse with a major a z x is of some 22 kilo–

    meters (217). Greater add more irregular motions would previal on disturbed days.

            The surface aspect of the field is, of course, somewhat different from

    the smooth "primal" pattern discussed above, because of the effect of the

    local irregularities, which are nowhere entirely absent. Instead of a

    distinct minimum or maximum of potential at a given spot, there is presumably

    a cluster or swarm of local salients, the actual number of poles varying

    according to the severity of the local irregularity encountered as the

    primal salient shifts from place to place. (At any given moment, if there

    are n of these poles in all, there will be ( n − 1) nodes or false poles,

    each of which may be looked on as a "saddle" of the equipotential "contours" .)

    Whichever one of the local salients happens to be momentarily the site of

    the absolute minimum of potential will be at that instant the principal

    magnetic pole. Only by knowing in detail the successive positions of the

    principal pole throughout an extended period of time could we make a rigorous

    determination of a mean position such as would be desirable for magnetic

    charts of the area.

            Present Outlook . In addition to the problem of mapping the primal field

    around the Pole of Poles, there are several other outstanding questions calling

    for study (1). Details of the daily variation patterns are not yet known with

    enough precision to permit, for example, using the registrations of a magnetic

    observatory to correct the determinations made by field parties some distance

    away. There are not enough arctic observatories (or, alternatively, not

    054      |      Vol_I-0810                                                                                                                  
    EA-I. Knapp: Geomagnetism

    enough sustained field work of the requisite standard) to fix precisely the

    patterns of secular change, which we know now to be quite irregular and

    unpredictable. The confusing detail of the registrations produced during

    magnetic storms, especially in the vicinity of the zone of maximum auroral

    frequency, needs to be unraveled and reduced to law.

            The most significant present trend in magnetic work a [?] regards the

    Arctic is clearly the development of techniques and apparatus for obtaining

    magnetic values of a relatively high accuracy from an airplane in flight (293).

    The basic principle of the saturable - - core reactor is the common denominator

    of this work, with overtones of the orientation and leveling problems inherent

    in such measurements (330). When sufficiently perfected and coupled with

    the essential ground control afforded by magnetograph stations, and by a net

    of ground "repeat" observations, these air-borne techniques will provide

    powerful new tools, before which some of the long-outstanding riddles of

    arctic geomagnetism may be expected soon to yield up their well-guarded

    answers.



    055      |      Vol_I-0811                                                                                                                  

    Lines of equal magnetic total intensity for 1925,

    according to Fisk.

    FIG. 2



    056      |      Vol_I-0812                                                                                                                  

    Lines of equal magnetic horizontal intensity for

    1925, according to Fisk.

    FIG. 3



    057      |      Vol_I-0813                                                                                                                  

    Magnetic meridian curves for 1925, according to Fisk.

    FIG. 4



    058      |      Vol_I-0814                                                                                                                  

    Distribution of magnetic activity, 1932-33. The numbers

    on the lines denote average range of total-intensity dis–

    turbance in gammas for 60 selected days of considerable

    disturbance. (After Vestine.)

    FIG. 5



    Bib. 1      |      Vol_I-0815                                                                                                                  
    EA-I. Knapp: Geomagnetism

           

    BIBLIOGRAPHY

            The language of each paper is that of the title here quoted, except as

    otherwise noted. All items directly cited have been examined, except these

    marked with an asterisk (*). The source list of Veinberg's (Weinberg's)

    Catalogue (item 40) is pre-eminent as a key to arctic data, but is not widely

    distributed and contains no actual data. Therefore, other lists are often

    cited herein in preference to item 40, particularly when the prior source

    presents no difficulty of access or identification.

            The cross references associated with a given item are separated by semi–

    colons. When page numbers are given they follow the shilling mark, with

    commas and short dashes used in the usual way to link two or more page citations.

    Thus, under item 92 the notation "111/465-6, 491" is to be read as "Item 111,

    pages 465, 466, and 491."

            A given cross reference takes in only the directly cited item, not any

    further cross references which may be appended to the latter.

           

    Part I. Articles that Deal with the Overall Topic

    or Contain Composite Data


    1. L. A. Bauer. "Unsolved problems in terrestrial magnetism and electricity

    in the polar regions," American Geographical Society of New York.

    Problems of Polar Research; a Series of Papers by Thirty-One Authors .

    [ ?] N.Y., The Society, 1928, pp.53-61. (Its Spec.Publ . no.7)

    Includes isogonic chart for 1926. Parts of text appeared earlier in

    Petermanns Mitt. Ergänzungach . Nr.191, p.47, 1928. For a recent treatment of

    the same topic see Arc. Inst.N.Amer. Bull . vol.1, esp. pp.4, 24-28,

    1946. See also item 39.

    2. Vanssay de Blavous. “Magnetic charts,” Hydrogr.Rev . vol.6, no.1, pp.67-82;

    [ ?] vol.6, no.2, pp.121-28, 1929. References on recent charts and

    on early expeditions and observatories.



    Bib. 2      |      Vol_I-0816                                                                                                                  
    EA-I. Knapp: Geomagnetism

    3. Richard Book and W. Schumann. “Katalog der Jahresmittel der magnetischen

    Elemente der Observatorien und der Stationen, an denen eine Zeitlang

    erdmagnetische Beobachtungen stattfanden,” Potsdam. Geophysikalisches

    Institut, Abhandlungen Nr.8-11, 1948. 4 vols. (Proof sheets only

    examined.) Fully documented and annotated. Includes graphs of

    values at many observatories. Arctic stations are in vol.1. See also

    item 10.

    4. Leonid Breitfuss. Die Erforschung des Polargebietes Russisch-Eurasiens .

    Gotha, 1925. Petermanns Mitt.Ergänzungsch. Nr.188, 1925. A good review,

    with specific mention of magnetic work at various points. Bibliography

    has 398 entries.

    4a. ----. “Der Sibirische Seeweg und seine physikalischen Verhaltnisse,” Arktis

    Jahrg.4, H.3/4, p.10, 1931. Includes two pages on magnetism, with

    reproductions of two isogonic charts.

    5. ----. Arktis, der derzeitige Stand unserer Kentnisse über die Erforschung der

    Nordpolargebiete . Berlin, Reimer; London, Sifton, Praed, 1939. In

    German and English, with historical and physical maps. Comprehensive

    list of expeditions and organizations, with concise [ ?] comments.

    6. Carnegie Institution of Washington. “Researches of the Department of Terres–

    trial Magnetism,” Carnegie Inst.Wash. Publ . no.175, 1912-47, vol.1-8.

    Vols. 3, 5 and 8 contain ocean observations.

    7. Sydney Chapman and Julius Bartels. Geomagnetism . Oxford, Clarenden press,

    2 vols. A comprehensive and well organized treatise. Of particular

    interest here are Chap.6, “A general review of the transient magnetic

    fluctuations,” and Chap. 25, “Theories of magnetic storms and aurorae.”

    See also Tables A and B, pertaining to magnetic observatories.

    8. L. Dunoyer. “L’exploration magn e é tique des mers et le progr e è s du magnetism

    terrestre durant la premier moiti e ê du XIXe si e è cle,” Revue G e é n.Sci.Pur .

    Appl . Vol.23, no. 3 2 , pp.46-59, 1912. General review, dealing with

    theoretical and actual distributi i o n of magnetism over the earth.

    Abstract by W. J. Peters in Terr.Magn . vol.20, p.190, 1915.

    9. Harlan W. Fisk. “Isomagnetic charts of the arctic area,” Amer.Geophys.un.,

    Trans . 1931, p.134. 5 charts with text--declination, dip, and horizontal

    and total intensity above 60° latitude, also magnetic meridian curves

    in same area. Epoch of all charts 1925.

    10. J.A. Fleming and W.E. Scott. “List of geomagnetic observatories and thesaurus

    of values.” In eight parts. Terr.Magn . vol.48, pp.97, 171, 237,

    1943; vol.49, pp.47, 109, 199, 267, 1944; vol.53, p.199, 1948. The

    first part and each of the last four parts include arctic data. The

    values given are annual means of seven magnetic elements, with footnotes

    explaining discontinuities, special conditions, etc. See also item 3.



    Bib. 3      |      Vol_I-0817                                                                                                                  
    EA-I. Knapp: Geomagnetism

    11. [A?] . W. Creely. Handbook of Polar Discoveries . 5th ed. Boston, Roberts, [ ?]

    1910.

    12. Christopher Hansteen. Untersuchungen über den Magnetismus der Erde .

    Christiania, Lehmann & Gröndahl, 1819. Note separate pagination of

    the “Anhang” containing tabulated data.

    13. K. Haussmann. “Erdmagnetische Forschung,” Petermanns Mitt.Ergänzungsch .

    Nr.216, pp.78-80, 1933. General review in connection with the arctic

    flight of the Graf Zeppelin.

    14. Daniel L. Hazard. Directions for Magnetic Measurements . 3d (1930) ed. —

    corrected 1947. Wash.,D.C., G.P.O., 1947. U.S.Coast & Geodetic Survey.

    Serial 166.

    15. [Johann G.] G. H a e llmann. “Magnetische Kartographie in historisch-kritischer

    Darstel l lung,” Preuss.Met.Inst. Abh . B.3, Nr.3 1909. ( Veröff . Nr.215.)

    Reviewed in Terr.Magn . vol.15, p.39, 1910.

    16. W. E. W. Jac [?] k son. “Magnetic observations in Canada made by authority of

    the Department of Marine and Fisheries, 1907 to 1910,” Roy.Soc.Can.,

    Proc . ser. 3, vol.5, sec.3, p.129, 1911. Includes historical summary

    of earlier work. Contains results of cruise of the Arctic, 1908-09.

    With [ ?] respect to the work at Stuparts Bay in 1884-85, see also

    Terr.Magn . vol.7, p.85, 1902.

    17. T. Rupert Jones, ed. Manual of the Natural History, Geology and Physics

    of Greenland and the Neighbouring Regions . Prepared for the use of

    the Arctic Expeditiin of 1875, under the Direction of the Royal

    Society. London, Stationery Office, 1875. Geomagnetism on pp.11-14

    and 691-712. Includes charts of declinati i o n, horizontal intensity

    and inclination.

    18. J. Henry Lefroy and G. M. Whipple. “Preliminary list of magnetic observa–

    tories,” Balfour Stewart. “Third report of the committee…appointed

    for the purpose of considering the best means of comparing and reducing

    magnetic observations,” Appendix III, Brit.Ass.Adv.Sci. Rep . 1887, p.327.

    Reprinted in Terr.Magn . vol.53, p.234, 1948, as part of item 10.

    19. H. G. Macht. “Das erdmagnetische Feld der Polargebiete,” Zeitschrift für

    Meteorol . Vol.1, pp.289-97, 1947. Abstracts in U.S.Geol.Surv. Geophys .

    Abetr . no.134, item 10262, 1948, and in Terr.Magn . vol.52, p. 503,

    1947. Mathematical treatment with special attention to the elongated

    distribution of the field in the Arctic.

    20. R. G. Madill. “The search for the North Magnetic Pole,” Arctic , vol.1, p.8,

    1948. See also items 29, 43.



    Bib. 4      |      Vol_I-0818                                                                                                                  
    EA-I. Knapp: Geomagnetism

    21. G. B. Neumayer. “Atlas des Erdmagnetismus,” Berghaus’ Physikalischer

    Atlas , Gotha, Perthes, 1891, Abt. 4. Includes numerous charts and

    36 columns of explanation. Epoch of charts 1885. Plate 42 brings

    out well the great elongation of the horizontal-intensity pattern

    in the Arctic.

    22. W. J. Peters. “Magnetic observations on a n m oving ice-floe,” Amer.Geophys.

    Un. Trans . 1931, p.132. Discusses effects of motion upon accuracy

    of observations. See also item 111/494.

    23. Edw. Sabine. “Contributions to terrestrial magnetism--No. 13. [Magnetic

    survey of the north polar regions.],” Roy.Soc.Lond. Proc . vol.162,

    p.353, 1872. Values arranged by longitude in 8 zones of latitude

    above 40° N. Confined largely to data obtained since 1820.

    24. Karl Schering. “Die Entwicklung und der gegenwärtige Standpunkt der erd–

    magnetischen Forschung,” Geographisches Jahrbuch vol.13, p.171, 1889.

    For continuation see item 25. This item contains a good review of the

    magnetic work of the International Polar Expedition.

    25. Karl Schering. “Bericht über die Fortschritte unserer Kenntnisse vom Mag–

    notismus der Erde,” Ibid . vol.15-44, 1891-1929. Numbered from 2 to 9;

    nos. 8, 9 by J. Bartels. The continuation of item 24; published as

    follows:

    Bericht Geographisches Jahrbuch

    no. Vol. Page Year

    2 15 141 1891

    3 17 1 1894

    4 20 3 1897

    5 23 3 1900

    6 28 291 1905

    7 36 79 1913

    8 40 316 1925

    9 44 1 1929

    26. Charles A. Schott. “Secular variation of the magnetic declination in the

    United States and at some foreign stations.” 7th ed., June, 1889.

    U.S. Coast and Geodetic Survey. Report of the Superintendent…fiscal

    year ending with June, 1888 . Wash.,D.C., G.P.O., 1889, App.7, pp.177-

    312. Includes (p.311) a brief discussion entitled: “Early attempts

    to locate the North American magnetic pole. )



    Bib. 5      |      Vol_I-0819                                                                                                                  
    EA-I. Knapp: Geomagnetism

    27. Ernst Harald Schütz. Die Lehre von dem Wesen und den Wanderungen der

    Magnetischen Pole der Erde . Berlin, Reimer, 1902. See also his

    article in Deutsche Geogr.Bl . vol.27, p.63, 1904.

    28. H. Spencer Jones. “The magnetic variation in the neighbourhood of the

    North Pole,” Geogr.J . vol.62, p.419, 1923. Includes revised isogonic

    chart for 1922. See also item 227.

    29. H. Spencer Jones. “The positions of the magnetic poles,” Polar Rec . vol.5,

    p.148, 1948. Reprinted in Hydrogr.Rev . vol.26, p.93, 1949. Good

    up-to-date account including history. See also item 20.

    30. Terrestrial Magnetism and Atmospheric Electricity, an International

    Quarterly Journal . Louis A. Bauer and John A. Fleming, editors.

    1896-1948, vol.1-53. Beginning with 1949, vol.54, the name was

    changed to Journal of Geophysical Research . References in this

    journal are written “ Terr.Magn .” in citations in this bibliography.

    31. U. S. Coast and Geodetic Survey. Annual Reports of the Superintendent ,

    1851-1907 . Wash.,D.C., G.P.O., 1852-1908. (Specific citations give

    the year, appendix number, and page.) For a long period virtually

    all the technical publications issued by the Survey were in the form

    of appendices to the annual reports, issued with the reports and also

    separately (as reprints).

    32. Louis A. Bauer. United States Magnetic Declination Tables and Isogonic

    Charts for 1902, and Principal Facts Relating to the Earth’s

    Magnetism . Wash.,D.C., G.P.O., 1902. U.S. Coast & Geodetic Survey.

    The “Principal Facts” portion was reprinted several times as a

    separate monograph of 97 pages. This part includes a table (pp.28-30)

    giving land values of magnetic declination observed before 1600.

    The main table in the other part includes considerable non-U.S.

    data, e.g., “Waters adjacent to Alaska and Eastern Siberia,” p.265.

    33. W. van Bemmelen. Die Abweichung der Magnetnadel: Beobachtungen, Säcular–

    variation, Wert- und Isogonensysteme bis zur Mitte des xviii ten


    Jahrhunderts . Batavia, Landsdrukkerij, 1899. Magnetische en Met.

    Obs., Batavia, Obsns . Supp. To vol.21. Includes many observations

    abstracted from ships’ logs.

    34. * Boris P. Veinberg. “Summary of magnetic determinations made in Siberia

    from 1820 to 1918. Part I. Published determinations,” Tomsk. Inst.

    de l’Exploration de la Sib e é rie, Travaux de la Section de la Geographie,

    Bull . vol.1, pp.1-69, 1920. Russian with English r e é sum e é . Cited in

    Terr.Magn . vol.28, p.123, 1923.



    Bib. 6      |      Vol_I-0820                                                                                                                  
    EA-I. Knapp: Geomagnetism

    35. ----. Katalog Magnitnykh Opredelenii . (Catalogue of magnetic determinations

    in U.S.S.R. and in adjacent countries from [156 ?] 1556 to 1926.) [i.e. ,

    to 1930.] Leningrad, Glavnaia Geofizicheskaia Observatoriia, 1929-1933.

    In three parts. Russian and English. The list of sources in

    Part 2 is arranged alphabetically according to the Russian spellings.

    Reviewed in Terr.Magn . vol.33, p.111, 1928.

    36. ----. “A preliminary list of arctic magnetic determinations,” Terr.Magn .

    vol.34, p.155, 1929. Gives year and observer to identify each

    expedition; an appeal for collaboration. No data given.

    37. ----. “A repliminary list of Antarctic and a supplementary list of arctic

    magnetic determinations,” Terr.Magn . vol.35, p.84, 1930. A check

    list similar in plan to item 36.

    38. ----. “Preliminary summary of data on the present distribution of magnetic

    declinati i o n in the arctic zone,” Zhurnal Geofiziki vol.2, no.2, p.254,

    1932. English, with Russian summary. Includes tabulated group means

    of observations, by position.

    39. ----. “Suggestions concerning field magnetic determinations in polar

    regions,” Ibid. vol.2, no.2, p.251, 1932. (cf. item 38) Urges

    more stations, even at the expense of accuracy, noting that accuracy

    better than 5 to 10 minutes in declination is illusory. Other

    cogent advice on arctic magnetic work.

    40. ----. Catalogue of Magnetic Determinations in the Polar Regions. Moscow,

    U.S.S.R. Tsentralnoe Upravlenie Edinoi Gidro-Meteorologicheskoi

    Sluzhby (Central Administration of the Hydro-Meteorological Service),

    1933. Sections 1 and 2. For [ ?] chronological key see item 36. Very

    comprehensive. In all, 13 sections were planned, of which these are

    the first two in one fascicule, containing the lists of sources for

    the Arctic and Antarctic, with full citations and many cross-references.

    Sources are arranged alphabetically by observers, with names of

    Russian observers transliterated to the Roman alphabet. The citation

    of this work in item 44 states that sections 3 to 10 were prepared

    for printing in 1934. They have not been seen, however. Regarding

    inclusion of references to this item, see not at beginning of this

    bibliography.

    41. ----. “Magnitnye opredelneniia v Arktike.” (Magnetic observations in the

    Arctic.) Priroda , Moscow, no.5-6, p.94-98, 1933. In Russian. A good

    over-all review.



    Bib. 7      |      Vol_I-0821                                                                                                                  
    EA-I. Knapp: Geomagnetism

    42. ----. “Magnitnye sklonenie, m n aklonenie i gorizontalnaia sostavliaiushchaia

    za 83° severnoi shiroty.” (Magnetic declination, dip and horizontal

    intensity beyound latitude 83° North.) Problemy Ark . no.5, p.41-48,

    1937. Russian, with English summary. Extracted from unpublished sec–

    tions of same author’s Catalogue (see item 40). Gives actual and

    reduced data and compares latter with some charts.

    43. ----. “Positions of the magnetic poles of the earth,” Akad.Nauk Izvestiia

    p.239, 1937. In Russian.

    44. ----. “International catalogue of magnetic determinations,” Terr.Magn .

    vol.42, p.214, 1937. Explanation of plan of a projected work and

    list of general sources. States that 15,885 determinations have

    been collected.

    45. John Wright. “Survey in polar expeditions,” Polar Rec . no.18, p.144, July,

    1939. Discusses details of survey work and equipment (theodolites,

    chronometers, etc.)

           

    Part II. References for Individual Undertakings

            The sequence follows that of the text citations, hence is roughly chrono–

    logical according to the date of the observations.


    46. Stephen Borough. “The nauigation and discouerie toward the riuer of Ob,

    made by Master Steuen Burrough, master of the pinnesse called the

    Serchthrift, with diuers things worth the noting, passed in the

    yere 1556,” Hakluyt, Richard. Hakluyt’s Collection of the Early

    Voyages, Travels, and Discoveries . London, Evans, 1809, vol.1,

    pp.306-12. See also items 32/28; 33/6; 35/240; 40/15.

    47. Gerrit de Veer. The Three Voyages of William Barents to the Arctic Regions ,

    (1594, 1595, and 1596 ). 2d ed. London, Hakluyt Society, 1876. (The

    Society Works . no.54) References to magnetic declination appear on

    pp. 10, 75, 84, 92, 154, 234, 236. See also items 32/28; 33/7;

    35/239; 40/12.

    48. See items 32/28; 33/7; 40/17.

    49. See items 12/24; 44; 33/9.

    50. Samuel Purchas. Purchas His Pilgrimes . London, William Stansby for Henrie

    Fetherstone, 1625. 5 vol. vol. 3. Voyages and Discoueries of the

    North Parts of the World, by Land and Sea, in Asia, Evrope; the Polare

    Regions, and in the North-west of America. Hudson’s two nar [?] atives

    are given on pp.574-95. See also items 12/21, 43; 33/10; 35/244;

    40/23.



    Bib. 8      |      Vol_I-0822                                                                                                                  
    EA-I. Knapp: Geomagnetism

    51. See items 11/20; 12/23; 43; 33/15; 40/11; 50/831.

    52. See items 33/10; 35/252; 40/31.

    53. See items 33/14; 35/252; 40/29; 50/541.

    54. See items 33/16; 35/245; 40/20; 50/553.

    55. See items 33/10; 40/35; 50/553.

    56. See items 33/16; 40/20; 50/720.

    57. See items 33/21; 40/37.

    58. See items 33/21.

    59. See [ ?] item 33/22.

    60. See item 33/22.

    61. See items 35/243; 40/44.

    62. Horace E. Ware. “Observations with the dipping needle at Boston in 1722,”

    Colonial Soc.Mass. Publ . vol.13, p.183, 1912. Contains a full reprint

    of Whiston [?] s 1724 publication.

    63. L. A. Bauer. “The earliest isoclinics and observations of magnetic force,”

    Phil.Soc.Wash. Bull . vol.12, p.397, 1894. Discusses Whi s ton’s

    publications.

    64. W. N. McFarland. “Early declination-observations, Kamchatka to Bering

    Strait,” Terr.Magn . vol.35, p.161, 1930. See also items 31 (1891

    Rep . App.5); 35/239; 40/14; 65.

    65. F. A. Golder. Bering’s Voyages: an Account of the Efforts of the Russians

    to Determine the Relation of Asia and America . N.Y., American

    Geographical Society, 1922-25. 2 vols.

    66. See items 35/260; 40/40; 65; 245/117-18, 124, 126.

    67. See items 40/40.

    68. See items 35/239; 40/13.

    69. See items 35/259; 40/38.

    70. See items [ ?] 12/8 (Anhang); 35/258; 40/34.

    71. See items 35/252; 40/30.



    Bib. 9      |      Vol_I-0823                                                                                                                  
    EA-I. Knapp: Geomagnetism

    72. See items 12/1-5 (Anhang); 35/244; 40/23.

    73. See items 12/1-5 (Anhang); 40/22.

    74. See item 12/1, 2, 35, 36 (Anhang).

    75. See items 35/264; 40/39.

    76. See items 35/273; 40/16.

    77. See items 35/259; 40/38.

    78. See items 12/65; 12/4, 37 (Anhang); 35/239; 40/13.

    79. A. R. Martin. “Dagbok hållen vid en resa till Norrpolen eller Spitsbergen,

    på Kongl. Vetenskaps-Akademieas omkostnad och med ett Grönlandska

    Compagniet i Göteborg tillhörande skepp år 1758 förrättad af Anton

    Rolandsson Martin,” Ymer vol.1, p.102, 1881. Magnetic data on p.140.

    See also item 40/17.

    80. See items 23/422; 40/34; 154.

    81. See items 35/244; 40/24.

    82. See items 35/238, 247; 40/9.

    83. W [?] i lliam Bayly. The Driginal Astronomical Observations made in the Course

    of a Voyage to the Northern Pacific Ocean for the Discovery of a

    North East or North West Passage … in His Majesty’s ships the

    Resolution and Discovery . London, Richardson, 1782. See especially

    pp.177-227 and 289-307. See also items 35/250; 40/15, 17.

    84. See items 35/239; 40/14; 245/126.

    85. See items 35/244; 40/20.

    86. See items 35/249; 40/27.

    87. See items 35/259; 40/22; 122; 245.

    88. William Score [?] s by. “On the anomaly in the variati i o n of the magnetic needle,

    as observed on ship-board,” Roy.Soc.Lond. Philos.Trans . vol.109, pt.1,

    p.96, 1819. Also in his An Account of the Arctic Regions with a

    History and Description of the Northern Whale-Fishery . London, Hurst,

    Robinson, 1820, vol.2, App.9, pp.537-54. i A careful investigation of

    the effect of the magnetism of the ship.



    Bib. 10      |      Vol_I-0824                                                                                                                  
    EA-I. Knapp: Geomagnetism

    89. ----. Journal of a Voyage to the Northern Whale-Fishery; Including

    Researches and Discoveries on the Eastern Coast of West Greenland,

    Made in the Summer of 1822 in the Ship Baffin of Liverpool. Edin–

    burgh, Constable, 1823. See also item 23/420.

    90. See items 35/272; 111/463, 484.

    91. See items 40/34; 95.

    92. Edward Sabine. “On irregularities observed in the direction of the compass

    needles of H.M.S. Isabella and Alexander, in their late voyage of

    discovery, and caused by the attraction of the iron contained in the

    ships,” Roy.Soc.Lond. Philos.Trans . vol.109, pt.1, p.112, 1819. See

    also items 17/691; 23/423-24; 40/38; 111/465-66, 491.

    93. See items 23/422; 40/19, 20; 98.

    94. See items 16; 17/692; 23/465-66, 491; 40/13, 38; 111/418 + - 20.

    95. Christopher Hansteen. “Forsög til et magnetisk haeldings-kart, konstrueret

    efter [ ?] iagttagelserne paa de seneste Engelske Nordvest–

    Expeditioner under Capitainerne Ross og Parry,” Magazin for Naturvide sn ns k .

    vol.5, pp.203-12, 1825. German translation in Annalen Phys ., Leipzig,

    vol.4, p.277, 1825. See also items 17/693; 23/407, 413; 40/33.

    96. W. E. Parry and H. Foster. “Magnetic observations at Point Bowen, etc.

    A.D. 1824-25, comprehending observations of the diurnal variation

    and diurnal intensity of the horizontal needle; [ ?] also on the dip of

    the magnetic needle at Woolwich, and at different stations, within the

    Arctic Circle,” Roy.Soc.Lond. Philos.Trans . vol.116, pt.4, p.73, 1826.

    See also items 17/694; 23/414, 419-20; 40/17, 19, 33, 34.

    97. Henry Foster. “Observations on the diurnal variation of the magnetic

    needle, at the Whale Fish Islands, Davis’s Strait,” Roy.Soc.Lond.

    Philos.Trans . vol.1 [?] 116 , pt.4, p.71, 1826. Observations over a 3-day

    period while awaiting trans-shipment of equipment. The station is

    in Disko Bay, not far from Godhavn.

    98. F. W. Beechey. Narrative of a Voyage to the Pacific and Beering’s Strait

    to Co-operate with the Polar Expeditions; Performed in H.M.S. Blossom

    … in the Years 1825, 26, 27, 28 . London, Colburn & Bentley, 1831.

    2 vols. Especially pp.733-42. See also items 23/391, 412, 418;

    32/128; 35/239, 243, 268; 40/13, 43.

    99. Nell de Br e é aut e é . “Relation du voyage du capitaine Guedon a à la baie de

    Baffin, sur le b a â timent baleinier fran c ç ais le Groenlandais, pendant

    l’annee 1825,” Annales Marit.& Colon . vol.11, pt.2, t.1, pp.204-26,

    1826. See also item 40/21.



    Bib. 11      |      Vol_I-0825                                                                                                                  
    EA-I. Knapp: Geomagnetism

    100. John Franklin. Narrative of a Journey to the Shores of the Polar Sea ,

    in the Years 1819, 20, 21 and 22 . London, Murray, 1823. See

    especially App.IV, “Remarks and tables connected with astronomical

    observations,” pp.629-45. See also items 23/401; 40/11, 20, 23.

    101. ----. Narrative of a Second Expedition to the Shores of the Polar Sea

    in the Years 1825, 1826, and 1827 . London, Murray, 1828. See

    especially App. V and VI, pp.cxxix--cxliv. Veinberg gives a cor–

    rection to certain data in this sche [?] d ule. See also items 16; 23/400,

    406, 412-13, 418; 32/128, 265; 40/11, 20, 26, 37.

    102. John Ross. Narrative of a Second Voyage in Search of a Northwest Passage,

    and of a Residence in the Arctic Regions, During the Years 1829 ,

    1830, 1831, 1832, 1833. Including the Reports of … James Clark

    Ross … and the Discovery of the Northern Magnetic Pole . London,

    Webster, 1833. Chap.42, especially p.566. See also items 16;

    17/696; 23/413, 419; 27; 40/37; 103; 104.

    103. James Clark Ross. “On the position of the North Magnetic Pole,” Roy.

    Soc.Lond. Philos.Trans . vol.124, pp.47-52, 1834.

    104. A. Nippoldt. “Neuberechnung der Beobachtungen von James Clark Ross über

    die Lage des nördlichen magnetischen Pols der Erde,” Preuss.Met.Inst.

    Veröff . Nr.372, pp.137-43, 1930. (The Institute’s Bericht …1929.)

    Abstracted in Terr.Magn. vol.35, p.188, 1930. The matter is also

    discussed in N Nippoldt’s monograph in Einführung in die Geophysik .

    Berlin, Springer, 1929, B.2, T.1, p.53.

    105. George Back. Narrative of the Arctic Land Expedition to the Mouth of the

    Great Fish River and along the Shores of the Arctic Ocean, in the

    Years 1833, 1834, and 1835 . London, Murray. Especially pp.625-34.

    Some further data in the German edition, published at Leipzig, 1836.

    See also items 40/11; 106.

    106. S. Hunter Christie. “Discussion of the magnetical observations made by

    Captain Back, R. N. during his late arctic expedition,” Roy.Soc.Lond.

    Philos.Trans . vol.126, pp.377, 1836. Discusses some interesting

    theoretical points regarding observations near the magnetic poles.

    107. See item 40/11.

    108. See items 16; 23/406, 412-13; 32/128, 265; 40/40.

    109. See item 40/35.

    110. See items 23/409-11, 416-17, 422; 35/251; 40/29.



    Bib. 12      |      Vol_I-0826                                                                                                                  
    EA-I. Knapp: Geomagnetism

    111. Edward Sabine. “Experiments for determining the variation in the

    intensity of terrestrial magnetism,” his Account of Experiments to

    Determine the Figure of the Earth, by Mean s of the Pendulum Vibrating

    Seconds in Different Latitudes . London, Murray, 1825, pp.460-502.

    Includes chart of northern magnetic hemisphere, with circular F–

    isodynamic curves. Includes daily variation of declination at

    Hammerfest and Norway Island. See also items 23/422; 40/38; 154.

    112. See items 23/416, 422; 40/17, 19, 33-34, 37; 154.

    113. See items 23/416, 422; 35/248; 40/26; 124.

    114. See items 40/20; 195.

    115. See items 23/414; 40/20.

    116. Christopher Hansteen. “Magnetiske Iagttagelser paa Island og Spitsbergen,”

    Danske Vidensk.Selsk.Forh. Overs . 1861, pp.394- 3 4 08. See also items

    23/414-15; 40/14.

    117. See items 40/14, 29; 116.

    118. See items 10/200 (8th part); 23/409, 416; 40/15, 28-29; 154.

    119. * “Vtoraia ekspeditsiia Podporuchika Pakhtusova k Vostochnomu beregu Novoi

    Zemli v [ ?] 1834 i 1835 godakh,” Zapiski po Gidrografii vol.2,

    pp.1-163, 1844. (cf. item 229) See also items 35/258; 40/33.

    120. See items 23/416-17, 422; 35/258; 40/33; 119.

    121. See items 23/416; 35/253, 264; 40/31, 44.

    122. Ferdinand Petrovich Wrangel. Narrative of an Expedition to the Polar Sea,

    in the Years 1820, 1821, & 1822, & 1823 . 2d ed. London, Madden, 1844.

    For magnetic data see Appendix. See also items 23/411, 417, 423;

    32/266; 35/243; 40/10; 124; 245/124.

    123. See items 23/411, 417, 423; 35/243, 249; 40/10, 27; 124; 245/118-21.

    124. Christopher Hansteen and Christian Due. Resultate Magnetischer, Astrono–

    mischer und Meteorologischer Beobachtungen auf einer Reise nach dem

    Östlichen Sibirien in den Jahren 1828-1830
    . Christiania, Brøgger &

    Christie, 1863. See also items 23/404-05, 411; 32/265.



    Bib. 13      |      Vol_I-0827                                                                                                                  
    EA-I. Knapp: Geomagnetism

    125. G. Findlay. [?] D irectory for Behring’s Sea and Coast of Alaska.

    Arranged from [Findlay’s] Directory of the Pacific Ocean. Corrected

    from Charts of the United States Surveying Expedition under

    Command of Commodore John Rodgers, 1855, and from Surveys of

    Commander R. W. Meade, Jr . Wash.,D.C., G.P.O., 1869. (U.S.

    Hydrographic Office. [Publication no.20] Scattered through the

    text are values of declination from various sources, mostly dated

    from the Franklin search or early Russian explorations. None of

    them seems to be attributed to the 1855 expedition. Regarding

    Lütke’s results, see also items 31 (1885 Rep. App.6); 32/128, 265;

    35/251; 40/29; 189/530.

    [?]125a. A.T. Kupffer. Rec [?] e uil d’Observations Magn e é tiques Faites a St.-Peéters–

    bourg et sur d’autres Points de l’Empire de Russie
    . Leningrad,

    1837. Sitka data on pp.469ff. The data for 1832 and part of 1833

    are also given in a paper by same author An [a?] n alen Phys ., Leipzig,

    vol.31, p.193, 1834.

    126. See items 23/417; 35/253; 40/31.

    127. J. H. Lefroy. Diary of a Magnetic Survey of a Portion of the Dominion

    of Canada. Chiefly in the North-Western Territories. Executed in

    the Years 1842-1844 . London, Longmans, Green, 1883. Most of the

    data were given by Sabine in an earlier publication, Roy.Soc.Lond.

    Philos.Trans. vol.136, p.237, 1846. See also items 40/14, 28; 136.

    128. See items 23/405-06, 412; 35/253; 40/31.

    129. See items 23/405-06, 412, 417; 32/128, 265-66; 35/248; 40/26.

    130. See items 23/405-06, 411-12, 417-18; [ ?] 32/265-66; 35/248; 40/26.

    131. Edward Sabine. “On hourly observations of the magnetic declination made

    by Captain Rochfor d t Maguire, R. N., and the officers of H.M.S.

    ‘Plover’ in 1852, 1853, 1854 at Point Barrow, on the shores of the

    Polar Sea, ’ Roy.Soc.Lond. Philos.Trans . vol.147, pp.497-532, 1857.

    See also items 17/700; 23/418; 32/128; 35/253; 40/30; 132; 143; 144.

    132. ----. “On the amount and frequency of the magnetic disturbance and of

    the aurora at Point Barrow, on the shores of the B P olar Sea,” Brit.

    Ass.Adv.Sci. Rep . pt.2, p.14, 1857.

    133. See items 23/405-06, 412, 418-19; 32/265; 35/249; 40/17.

    134. See items 23/418; 32/128; 40/30.

    135. See items 23/419-20; 40/15, [?] 37.



    Bib. 14      |      Vol_I-0828                                                                                                                  
    EA-I. Knapp: Geomagnetism

    136. J. H. Lefroy. Magnetic and Meteorological Observations at Lake Athabasca

    and Fort Simpson … and at Fort Confidence … London, Longman, 1855.

    See also items 16; 40/35, 37; 189.

    137. See items 23/419-20, 423-24; 40/9, 33.

    138. See item 40/26.

    139. See items 23/414; 40/25.

    140. See items 23/414, [ ?] 419, 423; 40/9, 13, 21, 26, 30, 37.

    141. See items 23/414, 419-20, 424; 40/14.

    142. See items 17/697; 23/423-24; 40/25, 40; 144; 171-630.

    143. Edward Sabine. “Results of hourly observations of the magnetic declina–

    tion made by Sir Francis Leopold McClintock, and the officers of the

    yacht ‘Fox,’ at Port Kennedy, in the Arctic Sea, in the winter of

    1858-59; and a comparison of these results with those obtained by

    Captain Rochfort Maguire and the officers of H.M.S. ‘Plover’ in

    1852, 53 and 54, at Point Barrow,” Roy.Soc.Lond. Philos.Trans. [ ?]

    [ ?]

    vol.153, pp.649-63, 1864. Abstracted in the Society’s Proc. Vol.13,

    p.84, 1864. See also items 17/702; 23/413-14, 419-20; 40/29.

    144. Isaac I. Hayes and Charles A. Schott. “Physical observations in the Arctic

    Seas, made on the west coast of North Greenland, the vicinity of Smith

    Strait and the west side of Kennedy Channel, during 1860 and 1861,”

    Smithson.Contr.Knowl . vol.15, art.5, 1867. See also items 17/698;

    23/414, 420, 423; 40/22, 35, 171/630.

    145. See item 40/21.

    146. See items 17/611; 40/14-15, 21, 31; 171/630.

    147. E. W. Creak. “On the results of the magentic observations made by the

    officers of the arctic expedition 1875-76,” Roy.Soc.Lond. Proc . vol.29,

    p.29, 1879. Discusses differential results obtained by the wintering

    parties on the Alert Alert and the Discovery Discovery . See also items 17/11;

    40/9, 10, 13; 42; 171/630.

    148. Russia. Gornyi Department (Dept. of Mines). Annuaire Magn e é tique et

    M e é t e é orologique du Corps des Ing e é nieurs des Mines ou Recueil

    d’Observations M e é t e é orologiques et Magn e é tiques Faites dans l’ E É tendue

    de l’Empire de Russie. Ann e é es 1841-1846. Succeeded by item 148a.

    See also items 18; 31 (1883 Rep Rep . App.13); 125a; 189.

    148a. Leningrad. Glavnaia Geofizicheskiaia Observatoriia. Letopisi … Annales

    de l’Observatoire Physique Central Nicolas. Annees 1847-1867.



    Bib. 15      |      Vol_I-0829                                                                                                                  
    EA-I. Knapp: Geomagnetism

    149. William Healey Dall. “Forschungen in den Aleutischen Inseln, 1873.”

    Petermanns Mitt . vol.20, p.151, 1874. See also items 11/82-83, 189;

    31/117-18 (1873 Rep . App.11); 125.

    150. See items 31/187 (1867 Rep . App.18); 31/5-7 (1881 Rep . App.9).

    151. See items 31/177-81 (1869 Rep . App.8); 31/5-7 (1881 Rep . App.9).

    152. See items 11/83; 31/111 (1873 Rep . App.11); 31/5-7 (1881 Rep . App.9);

    32/125-8, 265; 149.

    152a. See item 193.

    153. See items 23/422; 40/16; 154.

    154. Karl Selim Lemström. “Magnetiska observationer under Svenska polar–

    expeditionen år 1868,” Svenska Vetenskapsakad. Handl . vol.8, no.8, 1870.

    Includes tables of prior observations in the vicinity north of

    74° latitude. See also items 17/612; 23/409, 416, 422; 40/28.

    155. W. von Freeden. “Die wissenschaftligen Ergebnisse der ersten Deutschen

    Nordfahrt, 1868,” Petermanns Mitt . vol.15, p.201, 1869. See also items

    23/422; 40/27.

    156. See items 17/703; 23/420; 40/15, 27.

    [ ?] 157. See items 23/422; 40/16, 25.

    158. * Ivan P. Belavenets. Magnitnyia Nabliudeniia Proizvedennyia vo Vremia

    Plavaniia Velikago Kniazia Aleksiia Aleksandrovicha Rechnym Putem

    iz Peterburga v Arkhangelsk, Belym Morem i Sev. Ledovitym Okeanom

    v 1870 Godu . (Magnetic Observations Carried our During the Voyage

    of the Grand Duke Alexei Alexandrovich by way of Rivers from Petersburg

    to Arkhangelsk, by way of the White Sea and the Arctic Ocean in 1870.)

    Leningrad, 1871. For a condensed report of this program in English

    see Roy.Soc.Lond. Proc . vol. 19, p.361, 1871. See also items

    23/395-96, 404, 410, 416; 35/239; 40/13.

    159. F. F. Miller. “Izsledovanie zemnago magnetizma v Vostochnoi Sibiri.

    Rezultaty ekspeditsii na Nizhniuiu Tunguzku 1 na Olenek v 1873 l

    1874.” (Observations of terrestrial magnetism in eastern Siberia.

    Results of the expedition to the Nizhniaia Tunguzka and Olenek in

    1873 and 1874.) Vsesoiuznoe Geogr.Obshch. C Z apiski vol.29, no.1, 1895.

    Includes a chart of declination and dip, and another showing distribution

    of annual change. See also item 245.



    Bib. 16      |      Vol_I-0830                                                                                                                  
    EA-I. Knapp: Geomagnetism

    160. * Karl Weyprecht. “Die Magnetischen Beobachtungen der österreichisch–

    E ungarischen arctischen e E xpedition, 1872-74,” Akad.Wiss.Wien,Math.-Nat.

    Kl. Denkschr . vol.35, pp.69-292, 1878. For summary of magnetic work

    see Akad.Wiss.Wien Sitzungsber . vol.73, ser.2, p.313, 1876.

    See also items 17/709; 40/15, 43.

    161. August Wijkander. “Observations magn e é tiques faites pendant l’exp e é dition

    arctique su e é doise en 1872-73,” Svenska Vetenskapsakad. Handl . vol.13,

    no.15, 1874; vol.14, no.15, 1875. See also items 17/612; 40[?]/33; 202.

    162. Henrik Mohn and C. Wille. The Norwegian North Atlantic Expedition 1876-78 .

    Oslo, 1882. See also item 40/43.

    162a. A.de Bruyne, and others, eds. “De verslagen omtrent den tocht met de

    Willem Barents naar en in de Ijszee, in dem zomer van 1878,"

    Nederlan d sch Aardrijksk.Genoot Tijdschr . B.5, 1879. Magnetic work

    pp.66-71. Similar data for the summer of 1879 in same series, 1880,

    B.6, with magnetic work on pp.37-40. See also items 40/28, 40; 162b.

    162b * Verslagen Omtrent den Derden Tocht van de “Willem Barents” naar de

    Iis a z ee in den Somer van 1880, Uitgebracht aan het Comit e é van Uitvoering .

    Haarlem, 1881. Magnetic data pp.78-80. A similar publication for

    the 1881 voyage has magnetic data on pp.137-46.

    163. * M. S. Onatsevich. Sobranoie Nabliudenii. Proizvedennykh vo Vremia Gidro–

    graficheskoi Komandirovki v Veostochnyi Okean 1874-1878 g.
    (Collection

    of Observations Carried ourt During the Hydrographic Expedition to the

    Eastern Ocean, 1874-1878.) Leningrad, 1878. See also items 40/33; 187.

    164. August Wijkander. “Observations magn e é tiques, faites pendant l’exp e é dition

    de la Vega, 1878-80," Nils Adolf Erik Nordenskiöld, Vega-Expeditionens

    Vetenskapliga Iakttagelser . Stockholm, Beijer, 1882-87. 5 vol. Vol.2,

    pp.429-504. See also items 1/57; 32/128, 265-66; 40/23; 232/339.

    165. George W. and Emma DeLong. The Voyage of the Jeannette . London, Paul,

    Trench, 1883. 2 vol. See also items 35/273; 40/18.

    166. See items 32/128, 265; 40/23.

    167. See items 32/265; 40/14.

    168. Emil Edlen von Wohlgemuth. Die [?] österreichische Polarstation Jan Mayen .

    Wien, 1887. 3 vols. 2B., 2 Abt. There was intense local [ ?]

    irregularity in the vicinity of this station. See also items 24/211;

    25/361 (no.6); 202.

    169. * A. F. W. Paulsen. Exploration Internationale des R e é gions Arctiques,

    1882-83. Exp e é dition Danoise, Observations Faites a à Godthaab . Copen-

    hagen, Denmark. Meteorologiske Institut, 1889-93. 2 vol.



    Bib. 17      |      Vol_I-0831                                                                                                                  
    EA-I. Knapp: Geomagnetism

    170. G. B. von Neumayer and C. N. J. Börgen. Die Internationale Polarforsch–

    ung 1882-1883. Beobachtungs-Ergebnisse der Deutsche Stationen
    .

    Berlin, Asher Asher , 1886. 2 vol. "Magnetische Beobachtungen," vol.1, Ascher ✓

    pp.183-410, followed by earth current and auroral observations.

    See also items 24/211; 25/361 (no.6) ; 180.

    171. Adolphus W. Greely. International Polar Expedition. Report on the Pro–

    ceedings of the United States Expedition to Lady Franklin Bay,

    Grinnell Land Grinnell Land
    . Wash., D.C., G.P.O. 1888. 2 vol. Vol.2, pp.455-74

    contains a good bibliography, “Authorities on arctic meteorology.”

    Appendix 139, by C. A. Schott, pp.475-655, includes the magnetic

    reductions. Data for earlier expeditions are summarized on p.630.

    See also items 24/211; 25/159 (no.2).

    171a. See items 193; 171-630.

    172. Henry P. Dawson. Observations of the International Polar Expeditions

    1882-83. Fort Rae . London, 1886. See also items 16; 24/211; 189.

    173. P. H. Ray. Report of the International Polar Expedition to Point Barrow,

    Alaska . Wash., D.C., G.P.O., 1885. U.S. Signal Office. Arctic

    Series of Publications . no.1. P. t 6, pp.443-674, “Terrestrial magnetism,” by C. A.

    Schott, contains the magnetic results. See also items 24/211; 31

    (1883 Rep ., App.13); 40/36; 189.

    174. V. E. Fuss, F. Müller, and N. Jürgens. Beobachtungen der Russischen

    Polarstation an der Lenamündung. I. Teil: Astronomie und Magnetische

    Beobachtungen 1882-1884 . Leningrad, 1895. See also items 40/18;

    245/119-21.

    175. Maurits Snellen and H. Ekama. Rapport sur l’Exp e é dition Polaire Neéer–

    landsise
    . Utrecht, Boekhoven, 1910. Magnetic results on pp. 97-98.

    176. K. P. Andreev and R. Z. Lenz. Beobachtungen der Russischen Polarstation

    auf Nowaja Semlja . St. Petersburg, 1886-91. 2 vol.

    177. [Karl] Selim Lemström and Ernest Biese. Exploration Internationale des

    R e é gions Polaires 1882-83 et 1883-84. Exp e é dition Polaire Finlandaise .

    Helsingfors, 1887. 3 vol. Vol.II. "Magn e é tisme terrestre.” See also

    item 24/211.

    178. Aksel S. Steen. Beobachtungs-Ergebnisse der Norwegischen Polarstation

    Bossekop in Alten. 2 Theil. Erdmagnetismus, Nordlicht . Oslo, 1888.

    See also items 24/211; 202.

    179. E. Solander. Exploration Internationale des R e é gions Polaire 1882-1883.

    Observations Faites au Cap Thordsen, Spitzberg, par l’Exp e é dition

    Su e é doise . Stockholm, 1888. T. I:4. "Magn e é tisme terrestre.” See

    also items 25/159 (no.2); 40/18.



    Bib. 18      |      Vol_I-0832                                                                                                                  
    EA-I. Knapp: Geomagnetism

    180. G. Neumayer. Die Deutschen Expeditionen und ihre Ergebnisse, Germany .

    G B erlin, Deutsche Polar-Kommission, 1890. 2 vol. Chapter 1 contains

    a discussion of the International Polar Year expeditions of all

    countries participating, and incudes a striking pictorial drawing

    to show the total intensity over the world. See also item 24/211.

    181. G Lüdeli g n g “Über die tägliche Periode des Erdmagnetismus und der erd–

    magnetischen Störungen an Polarstationen,” Terr.Magn . vol.4, p.245, 1899.

    Accompanied by English abstract [ ?] by L. A. Bauer. (Similar material

    had been published in Akad.Wiss.Berl. Sitzungber . 1898, p.524.)

    181a. Bemmelen, W. van. “The diurnal field of magnetic disturbance,”

    Terr.Magn . vol.8, p.153, 1903.

    182. K. J. V. Steenstrup and R. R. J. Hammer. “Astronomiske observationer

    udførte i Nord-Grønland 1878-80,” Medd.Grønland vol.4, pt.6, pp.243-55,

    1883. See also items 40/21, 41; 195.

    182a. G. Holm, V. Garde, and C. Crone. “Magnetiske observationer, nordiys–

    iagttagelser og van d stands-maalinger 1883-85,” Ibid. vol.9, p.311, 1889

    (cf. item 182). See also item 10/202 (8th pt.).

    183. [?] Frode Petersen. “Opmaalingsexpedition til Egedesminde-Distrikt 1897,”

    Ibid . vol.14, p.263, 1898. (cf. item 182) i See also item 40/34.

    184. Voyage de “La Manche” a à l’ I Î le Jan-Mayen et au Spitzberg (Juillet-Ao u û t 1892) .

    Paris, Leroux, 1894. Magnetic data on pp.125.42. See also items 2;

    40/14.

    185. Carl Hartwig Ryder. Observations M e é t e é orologiques, Magneétiques et Hydro–

    meétriques de l’IÎle de Danemark dans le Scoresby Sound
    . Copenhagen,

    Denmark. Meteorologiske Institut, 1895. See also items 3; 10/200

    (8th pt.).

    186. E. von Drygalski and H. Stade. Grönland-Expedition der Gesellschaft für

    Erdkunde zu Berlin 1891-93 . Berlin, 1897. “Erdmagnetische Beobachtunge n ,”

    also items 25/359 (no.6); 40/40.

    187. E. Stelling. “Magnetische Beobachtungen in Lena-Gebiet im Sommer 1888 und

    Bemerkungen über die säcular Aenderung der Erdmagnetischen Elemente,”

    Akad.Nauk Meteorologicheskii Sborn . vol.13, no.4, 1890. Includes

    review of e r a rlier data for secular change.

    188. Aksel S. Steen. “Terrestrial magnetism,” Fridtjof Nansen, ed. Norwegian

    North Polar Expedition, 1893-96. Scientific Results . Christiania,

    Dybwad, 1901, vol.2, no.7. Summari a z ed by D. L. Hazard in Terr.Magn .

    vol.6, p.27, 1901. See also items 25/291 (no.6); 35/260, 273-74;

    40/39; 42.



    Bib. 18a      |      Vol_I-0833                                                                                                                  
    EA-I. Knapp: Geomagnetism



    Bib. 19      |      Vol_I-0834                                                                                                                  
    EA-I. Knapp: Geomagnetism

    189. Charles A. Schott. “Results of magnetic observations at stations in

    Alaska and in the northwest territory of the Dominion of Canada.

    Observations … in the Years 1889, 1890, and 1891…,” U.S. Coast and

    Geodetic Survey. Annual Report , 1892. Wash., D.C., G.P.O., 1894,

    pt.2, App.11, pp.529-533. Includes daily-variation table for

    earlier stations. See also items 31/87 (1891 Rep .); 40/18, 41.

    190. See items 31/152-55 (1896 Rep . App.1); 40/18, 30, 41; 189.

    191. See items 31 (1894 Rep . App.4); 31/270-75 (1895 Rep . App.1); 31/152-55

    (1896 Rep . App.1); 32.

    192. See items 31/498 (1891 Rep . App.14); 32.

    193. U.S. Hydrographic Office. Contributions to Terrestrial Magnetism, the

    Variat i ion of the Compass. From Observations Made in the United States

    Naval Service During the Period from 1881 to 1894 . Wash., D.C., G.P.O.,

    1894. (Its Publ . no.109) See particularly pp.34-36 for data from

    high [ ?] northern latitudes.

    194. Owen B. French. “Magnetic declinations observed near the Spitzbergen

    islands in 1894,” Terr.Magn . vol.1, p.85, 1896. See also item 40/20.

    195. George R. Putnam. “Results of magnetic observations made in connection

    with the Greenland expedition of 1896, under ch ra ar ge of Prof. A. E.

    Burton,” U. S. Coast and Geodetic Survey. Annual Report , 1897. Wash.,

    D.C., G.P.O., 1898, App.5, pp.285-95. Reprinted from Technology Quart .

    vol.10, p.56, 1897. For summary of results see Terr.Magn . vol.2, p.32,

    1897. See also item 40/20, 35.

    196. See item 31/233 (1898 Rep . App.5).

    197. See item 31/301 (1902 Rep . App.5).

    198. Aksel S. Steen. Terrestrial Magnetism , Kristiania, Brøgger, 1907. Report

    of the Second Norwegian Arctic Expedition in the “Fram,” 1898-1902, no.6.

    199. E. Solander. D e é terminations Magn e é tiques Faites au Spitzberg pendant l’ E É t e é ,

    1899. Stockholm, 1903. Reviewed by J. A. Fleming in Terr.Magn. vol.10,

    p.57, 1905. See also items 199a; 200; 202.

    200

    199a. V. Carlheim-Gyllensköld. “Travaux de l’exp e é dition su e é doise au Spitzberg

    en 1898 pour la mesure d’un arc du m e é ridien. No.3. D e é termination des

    e é l e é ments magn e é tiques,” Svenska Vetenskapsakad. Öfvers.Förh . vol.56,

    p.901, 1899. Abstract including table of results in Terr.Magn . vol.7,

    p.99, 1902.

    200. N. V. Roze. “Nablioudeniia variatsionn a o i stantsii v Gornzunde.” (Observa–

    tions variom e é triques de la station a à Hornsunde.) Vsesoiuznyi Ark.Inst.,

    Leningrad, Materialy Izuch.Ark . vol.7, 1935. (In Russian and French.)



    Bib. 20      |      Vol_I-0835                                                                                                                  
    EA-I. Knapp: Geomagnetism

    201. “Aus den wissenschaftlichen Ergebnissen der Polarfahrt des ‘Matador’

    unter Führung des Kapt.-Leut. a. D. Oskar Bauendahl, Herbst und

    Winter 1900-1901,” Annalen Hydrogr ., Berl. vol.29, pp.414, 445,

    1901. Magnetic results p.456. See also item 25/362 (no.6).

    202. Axel Hamberg. “Astronomische, photogrammetrische und erdmagnetische

    Arbeiten der von A. G. Nathorst geleiteten schwedischen Polar–

    expedition 1898,” Svenska Vetenskapsakad. Handl , vol.39, n9 o .6, [ ?] 1905.

    See also item 40/21.

    203. Filip Åkerblom. “Exp e é dition de M. A.-G. Nathorst en 1899. D e é terminations

    magn e é tiques faites au B G rönland du nord-est,” Arkiv för Mat.Astr.Fys.

    vol.1, p.609, 1903. See also item 40/9.

    204. V. Hjort. “Observations magn e é tiques faites a à Tasiusak et a à d’autres

    points sur la c o ô te orientale di Groenland," G. C. Amdrup. Observations

    Astronomiques, M e é t e é orologiques et Magn e é tiques de Tasiusak dans le

    District d’Angmagsalik 1898-99. Faites par l’Exp e é dition Danoise .

    Copenhagen, Ged, 1904. See also items 40/9; 202.

    205. G. W. Littlehales. “Magnetic declinations by Peary in the arctic regions,

    1900-02,” Terr.Magn . vol.9, p.140, 1904. See also item 40/34.

    206. Luigi Palazzo. “Osservazione magnetiche eseguite dal Conte Umberto

    Cagni nella Baia di Teplitz,” Observazione Scientifiche Eseguite

    durante la Spedizione Polare di S. A. R. Luigi Amedeo di Savoia,

    Duca degli Abruzzi 1899-1900 . Milan, Hoepli, 1903, pp.435-501.

    Reviewed by J. M. Kuehne in Terr.Magn . vol.8, p.92, 1903. See also

    item 40/16.

    207. Aksel S. Steen. “Jordmagnetiske malinger i Norge sommeren 1902,”

    Archiv f r ör Mat.Nat . vol.26, p.7, p.36, 1904. Abstract in Terr.Magn .

    vol.9, p.156, 1904. See also item 40/41.

    208. Julius Herrmann. “Die russischen hydrographischen Forschungen im nörd–

    lichen Eismeere in Jahre 1902,” Annalen Hydrogr ., Berl. vol.31, p.492,

    1903. A summary of original report by A. Warnek. For a further

    condensation in English see Geogr.Rev . vol.35, p.491, 1903. Magnetic

    data extracted in Terr.Magn . vol.9, p.45, 1904.

    209. de Vanssay. “Missions mgn e é tiques organis e é es par le Bureau des Longitudes

    en 1895-1896 sous la direction de M. le Capitaine des vaisseau de

    Bernardi e è res. Rapport d’ensemble," France. Bureau des Longitudes.

    Annales T.6. Paris, Gauthier-Villars, 1903, pp.A-1 - A183. See

    esp. p.20. See also item 40/31, 39.



    Bib. 21      |      Vol_I-0836                                                                                                                  
    EA-I. Knapp: Geomagnetism

    210. Kristian Birkeland. Norwegian Aurora Polaris Expedition 1902-03. Chris–

    tiania, Aschehoug, 1908-13. Vol.1, pts.1-2. “On the cause of

    magnetic storms and the origin of terrestrial magnetism.” See also

    preliminary announcement by same author, Terr.Magn . vol.7, p.81, 1902.

    See also items 3; 10/200-01 (8th pt.); 211; 233.

    211. Charles Chree. Studies in Terrestrial Magnetism . London, Macmillan, 1912.

    Chapter 13, “Comparison of arctic and antarctic disturbances” is based

    on Birkeland’s four arctic stations (see item 210) and on the records

    obtained simultaneously at the winter quarters of the “Discovery” in

    Antarctica.

    212. [L. A. Bauer.] “Norwegian expedition to the magnetic north pole,” Terr.Magn .

    vol.7, p.28, 1902. Includes brief letter from R. Amundsen and editor’s

    comments about magnetic conditions in the region, with a sketch map

    [ ?] by C. A. Schott showing declination and dip immediately around

    the supposed position of the pole. See also item 32/74.

    213. Roald Amundsen. “To the north magnetic pole and through the north-west

    passage,” Geogr.J . vol.29, p.485, 1907. Reprinted in Smithson.Inst.

    Ann.Rep . [ ?] 1906, p.249. For collateral references see Terr.Magn .

    vol.10, p.194 ; , 1905; vol.20, p.75, 1915.

    214. Nils Russeltvedt and Aage Graarud. “Die erdmagnetischen Beobachtungen der

    Gjöa-Expedition, 1903-1906. Vorläufige Mitteilung,” Geogysiske

    Publikasjoner vol.3, no.8, 1925. Summarized by the authors, with

    revisions, in Terr.Magn . vol.31, p.17, 1926.

    215. A Nippoldt. “Roald Amundsens neue Bestimmung des magnetischen Nordpols

    der Erde,” Weltall , Jahrg.25, H.9, pp.192-34, 1926. Discussion includes

    maps and diagrams showing daily and annual motions of pole.

    216. Nils Russeltvedt, Aage Graarud, Aksel S. Steen, and K. F. Wasserfall. “The

    scientific results of the Norwegian arctic expedition in the Gjöa 1903-

    1906 under the conduct of Roald Amundsen. Part 1. Scientific work of

    the expedition; Astronomy; Meteorology. Part 2. Terrestrial magnetism.

    Part 3. Terrestrial magnetism photograms,” Geofysiske Publikasjoner

    vol.6, 1932; vol7, 1933; vol.8, 1930. Described briefly in Terr.Magn . vol.

    36, p.71, 1931; vol.37, p.354, 1932; vol.38, p.343, 1933. This is the

    definitive publication. Items 212 to 217 all deal with this expedition.

    See also items 1/55; 16; 28; 40/9.

    217. K. F. Wasserfall. “Studies on the magnetic conditions in the region between

    Gjöahavn and the magnetic pole during the year 1904,” Terr.Magn . vol.44,

    p.263, 1939. Includes a recomputation of the position of the pole.

    See also Terr.Magn . vol.43, p.219, 1938.

    218. John A. Fleming, ed. The Ziegler Polar Expedition 1903-05, Anthony Fiala,

    Commander, Scientific Results . Wash., D.C., National Geographic Society,

    1907. Extended abstract in Terr.Magn . vol.12, p.105, 1907. Brief

    report in Terr.Magn . vol.10, p.130, 1905. See also items 3; 40/34.



    Bib. 22      |      Vol_I-0837                                                                                                                  
    EA-I. Knapp: Geomagnetism

    219. J. W. Tyrrell and C. C. Fairchild. “Exploratory survey between Great

    Slave Lake and Hudson Bay, districts of Mackenzie and Keewatin,”

    Canada. Department of the Interior. Annual Report 1900-01, pt.3,

    pp.98-155. Declination at 47 stations tabulated p.133. See also

    item 16; and Terr.Magn . vol.7, p.84, 1902.

    219a. H. Harrison. In Search of a Polar Continent, 1905-1907 . London,

    Arnold, 1908. The map accompanying this book has an inset table

    of 23 observed values of declination, and is reproduced in Geogr.J .

    vol.31, p.277, 1908. See also item 40/22.

    220. See items 16; 40/14, 24.

    221. See items 6/78, 85, 115 (vol.1); 40/17.

    221a. Brückmann, W. “Magnetische Beobachtungen der Danmark-Expedition,”

    Medd.Grønland (cf. item 182) vol.42, p.593, 1914. See

    also Geogr.J . vol.35, p.553, 1910.

    222. A. Nippoldt. “Magn e é tisme terrestre,” Duc d’Orleans. Campagne arctique

    de 1907 . Brussels, 1911, pp.4 7 9 -77. See also items 35/258; 40/35.

    223. H. Philipp. “Ergebnisse der Filchnerschen Vorexpedition nach Spitzbergen

    1910,” Petermanns Mitt.Ergänzungsch . Nr.179, p.48, 1914. See also item [ ?]

    40/19.

    224. See items 4/5; 35/242; 40/43.

    225. See items 4/69; 40/38; 245/113.

    226. Alfred de Quervain and P.-L. Mercanton. "Ergebnisse der schweizerischen

    Grönlandexpedition 1912- [ ?] 1913,” Schweizerische Naturforsch.Ges.,

    Zurich, Denkschr . vol.53, pp.11, 180, 1920. See also Medd.Grønland

    vol.59, pp.70, 186, 1925 (cf. item 182). Review including abstracted

    magnetic results given in Terr.Magn . vol.31, p.15, 1926. See also

    items 25/35 (no . 9); 40/31.

    227. F. A. McDiarmid. “Geographical determinations of the Canadian Arctic

    Expedition,” Geogr.J. vol.62, p.293. Magnetic results on pp.301-

    02. See also items 1; 28; 40/41.

    228. J. P. Ault and L. A. Bauer. “Magnetic declinations and chart corrections

    obtained by the ‘Carnegie’ from Hammerfest, Norway, to Reykjavik,

    Iceland, and thence to Brooklyn, New York, July to October, 194 1914,”

    Terr.Magn . vol. 19, p.234, 1914. Similar data for the segment of the

    cruise preceding arrival at Hammerfest are given on p.126. See also

    items 6/170, 286 ( [ ?] vol.3); 40/16.

    228a. J. P. Ault. “Magnetic declinations and chart correct i ions obtained by the

    Carnegie from Dutch Harbor, Alaska, to Lyttelton, New Zealand, [ ?]

    August-November, 1915,” Terr.Magn . vol.21, p.15, 1916. See also

    Terr.Magn . vol.20, p.104, 1915; vol.21, p.175, 1916; and his paper in

    Amer.Geophys.Un. Trans . 1926, p.131, also 1925, p.75. See also

    item 6/6, 10, 56, 70 (vol.5).



    Bib. 22a      |      Vol_I-0838                                                                                                                  
    EA-I. Knapp: Geomagnetism



    Bib. 23      |      Vol_I-0839                                                                                                                  
    EA-I. Knapp: Geomagnetism

    229. N. V. Roze. “Magnitnye nabliudeniia, proizvedennye v 1918, 1919, 1920

    i [ ?] 1921 g. g. na severe Evropeiskoi Rossii i poberezhi Severnogo

    Ledovitogo okeana.” (Magnetic observations carried out in 1918, 1919

    1920 and 1921 in north European Russia and on the shores of the

    Arctic Ocean.) Zapiski po Gidrografii vol.48, pp.77-105, 1924.

    See also items 4/18; 35/259; 40/37.

    230. J. Keränen. Results of magnetic observations in the years 1917, 1918,

    1922 and 1923 in North Finland,” Erdmagnetische Untersuch.Finnl . Nr.12.

    Helsinki, 1925. Related material by this author described in Terr.Magn .

    vol.26, p.75, 1921; vol.27, p.134, 1922; vol.30, p.156, [ ?] 1925.

    See also item 40/26.

    231. I. Zhongolovich. “Opredelenie astronomicheskogo i magnitnogo punkta v

    gube Chernoi na Novoi Zemle v 1921 g.” (Observations at an astronomical

    and magnetic station in Chernaia Bay, Novaia Zemlia, in 1921.)

    Zapiski po Gidrografii vol.48, p.195-99, 1924. In Russian. (Cf. item

    229) See also item 40/24-25.

    232. H. U. Sverdrup “Magnetic, atmospheric-electric, and auroral results,

    Maud expedition, 1918-25,” Carneg.Inst.Wash. Publ . no.175, vol.6,

    pp.309-524, 1927. Reviewed by H. W. Fisk and J. A. Fleming in Tree.Magn .

    vol.33, p.37, 1928. Includes a comparison of daily variation at seven

    arctic stations. Contains an isogonic chart, which also appears in

    item 4a. See also items 1/56; 40/10, 27, 30, 43; 232a.

    [ ?]

    232a. H. U. Sverdrup and C. R. Duvall. “Results of magnetic observations on

    the ‘Maud Expedition, 1918-1921,” Terr.Magn . vol.27, p.35, 1922.

    This account of the eastward progress of the expedition is devoted

    primarily to the many land observations ma d e in the U.S.S.R.

    233. O. Krogness. “The importance of obtaining magnetic registration from a

    comparatively close net of stations in the polar regions,” “Various

    papers on the projected co-operation with Roald Amundsen’s North Polar

    expedition,” Geofysiske Publikasjoner vol.3, no.4, 1920.

    234. See item 4/15, 51.

    235. E. Deville. “Magnetic declination results. Topographical Survey of Canada,

    Franklin District, Northwest Territories, Canada, 1923,” Terr.Magn .

    vol.29. p.47, 1924. See also item 40/22.

    236. See items 1 / ; 6/62, 208, (vol.6); 40/23.

    237. See items 1; 3; 6/65, 144, 261 (vol.6); 40/20.

    238. See Items 1; 40/37; 289/13.



    Bib. 24      |      Vol_I-0840                                                                                                                  
    EA-I. Knapp: Geomagnetism

    239. P. L. Mercanton. “Rapport sur les observations de magn e é tisme terr s e stre

    faites au cours de la croisi e é re du ‘Pourquois Pas?’ durant l’ e é t e é de

    1929,” Annalen Hydrogr ., Berl. ser.3, vol.10, p.87, 1930.

    240. E. R. Relf. “Central Spitzbergen and North-East Land. II. The cruise of

    the ‘Termingen,’” Geogr.J . vol.64, p.204, 1924. See also item 2 4 0/36.

    241. F. C. Binney. “The Oxford Univeristy Arctic Expedition, 1924. Appendix V.

    Magnetic observations (E. Relf),’ Ibid . vol.66, p.129, 1925. See also

    item 40 . / 37.

    242. H. G. Watkins. “The Cambridge expedition to Edge Island,” Ibid . vol.72,

    p.117, 1928. Magnetic results given in Appendix 2, also in Terr.Magn .

    vol.32, p.147, 1927.

    24 3 2 a. K. Wilkins. “The advisability of geophysical investigation in the Arctic

    by submarine,” Amer.Geophys.Un. Trans . [?] 1930, pp.125-26. See also item

    6/71, 110 (vol.8).

    243. P. Collinder. “Variation of the compass south of Franz Joseph Land,”

    Terr.Magn . vol.35, p.114, 1930.

    [?]

    244. N. E. Malinin. “Sur les variations s e é culaires du magn e é tisme terrestre

    au nord de la Russie d’Europe,” Zhurnal Geofiz i . Met . vol.1, no.1, pp.19-35,

    1924. (Russian with French reésumeé.) Includes a table of repeat observa–

    tions at about 40 stations. See also item 34.

    245. E. V. Shtelling, D. A. Smirnov, and N. V. Roze. “Resultaty ezhechasnykh

    nabliudenii nad magnitnym skloneniem, proizvedennykh vo vremia

    zimovok Russkoi Poliarnoi Ekspeditsii, 190[0?]-1902.” (Contributions to

    the study of terrestrial magnetism in Yakutia.) Akad.Nauk. Komissia

    Izucheniiu Yakutskoi Avtonomnoi. Trudy vol.2, pp.1-143, 1926. (Russian

    with English summary.) Of the four parts, the first two cover the work of the

    Toll expedition of 1900-03, the third gives results of three unrelated

    campaigns dating from 1893 to 1911, and the fourth summarizes all known

    work in the area. Reviewed by H. U. Sverdrup (see item 232/369, 423).

    246. N. V. Roze. “Problemy izucheniia zemnogo magnetizma na territorii Yakutii.”

    (Certain problems in the [?] study of terrestrial magnetism in Yakutia.)

    Ibid . vol.11, pp.183-95, 236-37, 1928. Reviewed in Terr.Magn. vol.33,

    210, 1928. (Russian with English summary.) Includes isogonic chart for

    1925.

    247. N. V. Roze. “Zur Konstruktion von magnetischen Karten für die arktische

    Zone der U.S.S.R.,” Petermanns Mitt.Ergänzungsch . Nr.201, p.46, 1929.

    Includes 3 charts. Abstracted by Blavous (see item 2 above).

    248. See items 40/37; 42.



    Bib. 25      |      Vol_I-0841                                                                                                                  
    EA p - I. Knapp: Geomagnetism

    249. R. E. G. Amundsen and Lincoln Ellsworth. First Crossing of the Polar Sea .

    N.Y., Doran, 1927. This volume cited for Riiser-Larsen’s account,

    though it seems to contain no [ ?] magnetic data.

    250. Hubert Wilkins. “The flight from Alaska to Spitsbergen, 1928, and the

    preliminary flights of 1926 and 1927,” Geogr.Rev . vol.18,p.527, 1928.

    251. L. Palazzo. “Vorstudien für die erdmagnetischen Forschungen auf der

    Luf t schiffexpedition in die Arktis,” Petermanns Mitt.Ergänzungsch . Nr.205,

    pp.80-86, 1929. Gives observing [ ?] program and instrumental

    details. See also related discussion, pp.22, 36, 87-88, 94.

    252. G. Romagna Manoia. “Spedizione artica della regia nave ‘Citt a à di Milano’

    Anno 1928. Ricerche magnetiche, by Mario Tenani,” Annali Idrogr . vol.12,

    p.161, 1939. See also item 40/41.

    253. Gustaf S. Ljungdahl. “Preliminary report of the magnetic observations

    made during the Aeroarctic expedition of the ‘Graf Zepplin’ 1931,”

    Terr.Magn . vol.36, p.349, 1931. (The same data are given in Petermanns

    Mitt.Ergänzungsch . Nr.216, p.81, 1933.) For another discussion of the

    magnetic work see Gegor.J. vol.22, p.61, 1932. See also items 13; 254.

    254. * K. Haussmann. Karte der Magnetischen Meridiane für 1931 zwischen M N owaja

    Semlija und den Neu-Sibirischen Inseln . Scale 1:5,000,000. 118 by 108 cm.

    Berlin, Internationalen Gesellschaft Aeroarctic, 1931. Includes

    statement of published sources used.

    255. C. A. French and R. G. Madill. “Magnetic results, 1921-23,” Ottawa.Dom.Astr.

    Obs. Publ. vol.8, p.135, 1927.

    256. C. A. French and R. G. Madill. “Magnetic results, 1927-37,” Ibid . vol.11,

    p.259, 1940.

    257. Karl Schering. “Karte der erdmagnetischen Observatorien,” Petermanns Mitt .

    vol.59, pt.2, p.146, 1913. Stations in seve m n categories are shown by

    different symbols.

    258. N.N. Nikolskil. “Polar magnetic observatories of the U.S.S.R.,” Informatai–

    onnyi Sbornik Magn.& Elekt
    . no.4. Leningrad, 1937, p.101. Summarized in

    Terr.Magn . vol.43, p.333, 1938. Cf. articles by Pushkov and Roze, Terr .

    Magn . vol.40, p.393, 401, 1935. See also items 3; 276; 304; 305, 320a;

    331.

    258a. A. P. Nikolskii. “Magnitnye Nabliudeniia na Zemle Frantsa-Iosifa 1934-1936

    Godakh.” (Magnetic observations on Franz-Joseph Land, 1934- [ ?] 36.)

    Problemy Ark . no.4, pp.99-108, 1937. (cf. item 42.) Russian, with

    English summary.

    259. Carl Störmer. “Probleme und Richtlinien der künftigen Polarlichtforschung,”

    Arktis vol.1, p.70, 1928. Discusses by Heck, Amer.Geophys.Un. Trans .

    1929, p.67. See also item 7.



    Bib. 26      |      Vol_I-0842                                                                                                                  
    EA-I. Knapp: Geomagnetism

    260. John A. Fleming. “Progress-report on the International Polar Year of

    1932-33,” Amer.Geophys.Un. Trans . 1933, p.146. Inc n l udes a table showing

    the positions of 37 specially established stations and many other

    permanent stations that cooperated through special observations or

    registrations. See also items 233; 261; 262; 263; 264. See additional

    references at 264.

    261. John A. Fleming. “The relation of magnetic and electric work in the

    Pacific Ocean to the Polar Year campaign, 1932-33, : Pacific Science

    Congress. 5th, Vancouver, 1933. Proceedings vol.3, p.1685, 1934.

    Includes a list of special and cooperating observatories.

    262. J. Charcot. “L’ann e é e polaire 1932-1933. Historique et organization

    materielle,” France. Bureau des Longitudes. Annuaire pour l’An 1935.

    Paris, Gauthier-Villars, 1935, pp.A1 to A24. Details of French

    participation, preceded by a brief historical account covering the

    overall program.

    263. Ch. Maurain. “L’ann e é e polaire 1932-1933. Organisation g e é n e é rale et travaux

    scientifiques,” Ibid , pp. B1 to B22. A detailed statement of the back–

    ground and purposes of the program, with explanations of various

    problems to be studied.

    264. G. van Dijk. “Rapport sur la publication des caract e è res magn e é tiques

    pendant l’ann e é e polaire 1932-33,” Int.Geodetic & Geophys.Un.Ass.Terr.

    Magn.& Elect. Bull . no.10, pp.218-20, 1937. Also see p.417, and Bull .

    no.11, p.304. (Lists of stations showing types of data obtained.)

    See also Terr.Magn . vol.42, p.429, 1937 . , and Nature , Lond. Vol.164, p.170, 1949.

    265. R. Kanitscheider and M. Toperczer. “Bearbeitung des erdmagnetischen Beo–

    bachtungensmaterials der österreichischen Jan Mayen Expedition im

    Polarjahre 1932-33,” Akad.Wiss.Wien Sitzungsber . vol.144, p.517, 1935.

    266. J. P. Roth e é . “Sur la variati i o n diurne des el e é ments magn e é tiques au Scoresby

    Sund (Est-Groenland),” Terr.Magn . vol.40, p.165, 1935.

    267. J. P. Roth e é . “Observations magn e é tiques au Scoresby Sund pendant l’Ann e é e

    Polaire avec tableaux horaires des elements D, H, et Z,” Paris.Univ.Inst.

    Phys.Globe, Annales vol.13, pp.99-140, 1935; vol.14, pp.92-96, 1936.

    268. Ann e é e Polaire Internationale 1932-33. Participation Fran c ç iase . Paris,

    1936-38. 2 vol. Includes summary of older observations in the vicinity

    of Scoresby Sound. See also items 262; 266; 267.

    269. Netherlands. Meteorologisch Instituut. Observations Magn e é tiques a à

    Angmagssalik pendant l’Ann e é e Polaire Internationale 1932-33.

    De Bilt, 1940.



    Bib. 27      |      Vol_I-0843                                                                                                                  
    EA-I. Knapp: Geomagnetism

    270. Johannes EOlsen and Knud Thiesen. Anneée Polaire Internationale 1932-

    1933. Observations Magneétiques aà Julianehaab 1932-1934.

    Copenhagen, Denmark. Meteorologiske Institut, 1940.

    271. Viggo Laursen. Observations Faites aà Thule, Ann eé e Polaire Internationale

    1932-33. Pt.I. Magneétisme Terrestre. Copenhagen, Denmark.

    Meteorologiske Institut, 1943. See also Terr.Magn . vol.39, p.83, 1934.

    272. Canadian Polar Year Expeditions, 1932-33. Terrestrial Magnetism, Earth-

    Currents, Aurora Borealis
    . Ottawa, 1939. Vol.2: “Chesterfield Inlet,

    Meanook, Saskatoon.” Reviewed in Terr.Magn . vol.45, p.368, 1940.

    See also item 275.

    273. British Polar Year Expedition to Fort Rae, Northwest Canada, 1932-33.

    British Polar Year Expedition, Fort Rae, N.W. Canada, 1932-33.

    London, Published under the direction of the British National Committee

    for the Polar Year, the Royal Society, 1937. 2 vol. Reviewed in

    Terr.Magn. vol.42, p.330, 1937.

    274. H. Herbert Howe. Magnetic Observatory Results at College, near Fairbanks.

    Alaska for the Second Polar Year, October, 1932 to March, 1934 . Wash.,

    D.C., G.P.O., 1944. U.S. Coast & Geodetic Surv. [?] M O no.21.

    275. Frank T. Devies. “The diurnal variation in magnetic and auroral activity at

    three high-latitude stations,” Terr.Magn . vol.40, p.173, 1935. Uses

    data from Chesterfield Inlet and Point Barrow stations of the Polar

    Year 1932-33. Regarding Point Barrow, see also item 6/73, 111 (vol . 8).

    276. I. L. Rusinova, ed. “Rezultaty magnitnykh nabliudenii poliarnykh magnitnykh

    observatorii Matochkin Shar, Zemlia, Frants-Iosifa i Dikson za 1933 god.”

    (The results of magnetic observations of the magnetic observatories of

    Matochkin Shar, Franz Josef Land and Dickson, 1933.) Leningrad.

    Arkticheskii Nauchyi-Issled.Inst. Trudy vol.78, pp.21-63, 1937.

    Headings of tables given in Russian and French. See also items 3; 258.

    277. Mauri Tommila. Ergebnisse der Magnetischen Beobachtungen des Polarjahr-

    Observatoriums zu Petsamo im Polarjahre 1932-1933.
    Helsinki, Akad.

    Wissen., Geophysikalischen Observatorium, 1937.

    278. Leiv Harang, et al. “Norwegian publications from the International Polar

    Year 1932-33. No.2: Work on terrestrial magnetism, aurora and

    allied phenomena,” Norske Institutt for Kosmisk Fysikk, Tromsø,

    Publikasjoner Nr.6, 1935. Contains results of observations at

    Bossekop, Tromsö and Bodö, including a separate report on rapid

    oscillations recorded at the latter two stations.



    Bib. 28      |      Vol_I-0844                                                                                                                  
    EA-I. Knapp: Geomagnetism

    279. Polska Ekspedycja Narodowa Roku Polarnego 1932/33. Wyniki Spostrzeze n ń .

    Polskiej wyprawy Roku Polarnego 1932/33 na Wyspie Niedzwiedziej.

    R e é sultats des Observations de l’Exp e é dition Polonaise de l’Ann e é e

    Polaire 1932-33 a l’ I Î le des Ours . Warsaw, Drukarnia Pa n ń stwowego

    Instytutu Meteorologicznego, 1936. 4 vol. vol.2: “Magnetyzm

    Ziemski.”

    280. F. Lindholm. Swedish Polar Year Expedition, Sveagruvan, Spitzbergen,

    1932-33. General Introduction: Terrestrial Magnetism . Stockholm,

    1939. Reviewed by E. H. Vestine, Terr.Magn. vol.44, p.378, 1939.

    281. E. H. Vestine and S. Chapman. “The electric current-system of geo–

    magnetic disturbance,” Ibid . vol.43, p.351, 1938.

    281a. E. H. Vestine. “The geographic incidence of aurora and magnetic dis–

    turbance, northern menisphere,” Ibid . vol.49, p.77, 1944.

    282. M. Hasegawa. “Provisional report of the statistical study of the diu r nal

    variations of terrestrial magnetism in the North Polar regions,”

    Inst.Geodetic & Geophys.Un.Ass.Terr.Magn.[&?] Elect. Bull . no.11, p.311,

    1940. For a Russian study of the same topic see Pushkov, Klimat i

    Pogoda vol.11, no.4, p.25, 1935. Hasegawa used nineteen stations,

    Pushkov ten (five of which were from the first Polar Year).

    283. Fritz Errulat. “Über die mittlere Intensität von starken erdmagnetischen

    Stürmen in Abhängigkeit von der geomagnetischen Breite,” Germ.Hydrogr.

    Rev . vol.1, p.72, 1948. Has English abstract.

    284. Daniel L. Hazard. Terrestrial Magnetism. Alaska Magnetic Tables and

    [ ?] Magnetic Charts for 1920 . Wash.,D.C., G.P.O., 1920. U.S. Coast

    & Geodetic Surv. Spec.Publ. no.63. Tables of declinations from

    boundary and reconnaissance surveys on pp.23-26. Local anomalies

    are discussed in Amer.Geophys.Un. Trans . 1933, p.116.

    285. See item 284/10-13, 22.

    286. See item 284/22.

    287. Daniel L. Hazard. Results of Magnetic Observations Made by the United

    States Coast and Geodetic Survey in 1921 . Wash., D.C., G.P.O., 1922.

    U.S. Coast and Geodetic Surv. Spec.Publ . no.87.

    [ ?]

    288. See item 287/6.

    289. Daniel L. Hazard. Results of Magnetic Observations Made by the United States

    Coast and Geodetic Survey in 1925 . Wash.,D.C., G.P.O., 1926. U.S.

    Coast and Geodetic Surv. Spec.Publ . no.125.



    Bib. 29      |      Vol_I-0845                                                                                                                  
    EA-I. Knapp: Geomagnetism

    290. ----. Res [?] u lts of Magnetic Observations Made by the United States Coast

    and Geodetic Survey in 1928 . Wash., D.C., G.P.O., 1929. U.S. Coast

    and Geodetic Surv. Serial 455. See p.6.

    291. ----. Terrestrial Magnetism. Alaska Magnetic Tables and Magnetic Charts

    for 19k 1930 . Wash., D.C., G.P.O., 1934. Ibid . 570. See p.3.

    292. Henry R. Joestling. Magnetometer and Direct-Current Resistivity Studies

    in Alaska . N.Y., 1941., Amer.Inst.Min.Metall.Engrs. Tech.Publ . 1284.

    Reprinted with discussion added, in the Society’s Trans . vol.164,

    p.66, 1945.

    293. James R. Balsley, Jr. The Airborne Magnetometer . Wash., D.C., G.P.O., 1946.

    U.S. Department of the Interior. Geophysical Investigations. Prelimin–

    ary Report
    no.3. (Processed. ) Includes an illustrative map of an

    area of 18,000 square miles of Alaska adjoining the arctic coast east

    of Point Barrow, with anomalies of total intensity shown by means of

    isanomalic curves spaced at ten-gamma intervals. For a report about a comparable Soviet survey in the Kara Sea area,

    see Polar Re c . vol.5, p.336, 1949.

    294. Samuel A. Deel. Alaska Magnetic Tables and Magnetic Charts for 1940 . Wash.,

    D.C., G.P.O., 1944. U.S. Coast and Geodetic Surv. MO -8. (Processed)

    295. N. H. Heck. “Magnetic work of the United States Coast and Geodetic Survey,

    April 1939 to March 1940,” Amer.Geophys.Un. Trans . 1940, p.325. See

    also item 294/3-4.

    296. O. W. Swainson. “Magnetic work of the United States Coast and Geodetic

    Survey from April 1944 through March 1945,” Ibid . vol.26, p.447, 1945.

    297. Elliott B. Roberts. “Magnetic work of the United States Coast and Geodetic

    Survey from July 1, 1946 to June 30, 1947,” Ibid . vol.29, p.104, 1948.

    For results of the observations by Campbell see item 314.

    298. I. L. Russinova. “Magnitnye Nabliudeniia, Proizvedennye Ekspeditsiei na

    ‘Sibiriakove’ v 1932 g.” (Magnetic observations takes by the expedition

    on the “Sibiriakov” in 1932.) Leningrad. Arkticheskii Nauchyi-Issled.

    Inst. Trudy vol.33, pp.75-78, 1936. (cf. item 276) Russian, with

    brief English summary.

    299. P. E. Fedulov. “The work done in terrestrial magnetism by the expedition

    of the ‘Malygin’ in 1935,” Informatsionnyi Sbornik Magn.& Elekt . 1936,

    p.25. In Russian. Has only 5 paragraphs. (cf. item 258) See also

    Rogachev, same publication, no.4, p.28, 1937. See [ ?] also item 302.



    Bib. 29a      |      Vol_I-0846                                                                                                                  
    EA-I. Knapp: Geomagnetism



    Bib. 30      |      Vol_I-0847                                                                                                                  
    EA-I. Knapp: Geomagnetism

    300. I. A. Kireev, et al. Nauchnye Rezultaty Ekspeditsii na “Sedove” v 1934

    Gody. B.2. (The Scientific Results of the Expedition on “sedov” in

    1934. Part 2.) Leningrad, 1937. Leningrad.Arkticheskii M N auchyi-Issled.

    Inst. Trudy vol.83. (Cf. item 276) “Magnitnye nabliudeniia,” (Magnetic

    observations) by P. E. Fedulov, pp.21-33. Tabulation gives three

    elements and includes 14 stations. Russian text. See also item 302.

    301. E. K. R F edorov. “Magnitnye opredeleniia 1935 goda na Taimyrskom Poluostrove.”

    (Magnetic observations in 1935 on Taimyr Peninsula.) Ibid . vo . l .97,

    pp.63-76, 1937. Russian with English summary. (Cf. item 276) See also

    item [ ?] 302.

    302. “Notes. 20. Magnetic Survey of the U.S.S.R.,” Terr.Magn . [ ?] vol.42,

    p.333, 1937. Mentions a new isogonic chart of the Kara Sea, based on

    observations made in 1934-35.

    303. S. D. Lappo. “D e é clinaison magn e é tique dans la mer Lapt e é v,” Zhurnal

    Geofiziki vol.5, 1935. In Russian. (Cf. item 38) A review and

    comparison of scattered data since 1822.

    304. P. P. Lazarev, et al. “U.S.S.R. Report on work in terrestrial magnetism

    and electricity during 1936-1939,” Int.Geodetic & Geophys.Un.Ass.Terr.

    Magn.& Elect. Bull . no.11, pp.162-76, 1940. Abs. in Terr.Magn . vol.45,

    p.71, 1940.

    305. U.S.S.R. Glavnoe Upravlenie Severnogo Morskogo Puti. Gidrograficheskoe

    Upravlenie. Severnyi Morskoi Put. (U.S.S.R. Northern Sea Route Admin–

    istration. Hydrographic Office. North Sea Route.) Collection of

    Articles on Hydrography and Navigation. Leningrad, 1934-38. 10 pts.

    Pt.8, pp.72-74, contains “Establishment of a system of magnetic

    information in the Arctic,” by P. E. Fedulov. In Russian.


    Fedulov, P.E. “On the magnetic information in the Arctic,” U.S.S.R.

    Glavnoe Upravlenie Severnogo Morskogo Puti. Gidrograficheskoe

    Upravlenie. Severnyi Morskoi Put. (U.S.S.R. Northern Sea

    Route Administration. Hydrographic Office. North Sea Route.)

    Sbornik Statei po Gidrografice i Moreplavaniiu . (North Sea

    Route. Compendium of Articles on Hydrography and Navigation.)

    Pt.8, Leningrad, 1937, pp.72-76. In Russian.

    306. N. V. Roze. “Zadachi magnitnoi Semki, okolo severnogo poliusa.” (Problems

    of magnetic observations in vicinity of the North Pole.) Problemy Ark .

    no.4, pp.37-38, 1937. In Russian. (Cf. item 42)

    307. E. K. Fedorov. “Magnetic and elec g t rical observations [planned for] the

    drift expedition to the North Pole,” Informatsionnyi Sbornik Magn.& Elek .

    no.4. Leningrad, 1937, p.5. Russian with English summary. (Cf. item

    258) A general account of the scientific work appeared in Nature, Lond.

    vol.141, p.629, 1938. For r e é sum e é and table of magnetic work see

    Terr.Magn . vol.43, p.335, 1938, and corrigendum on p.408. See also

    item 306.

    308. * S. I. Issaev. “Magnitnye Nabliudeniia v Dreife L/P ‘Sedov’ s 27 Marta po

    27 Augusta 1938 goda.” (Magnetic observations on the drift of the “Sedov”

    from March 27 to August 27, 1938.) Problemy Ark . no.9, pp.83-88, 1940.

    (Cf. item 42) Briefed in Terr.Magn . vol.45, p.388, 1940. For a

    general account see Nature , Lond. vol.145, p.533, 1938.



    Bib. 30a      |      Vol_I-0848                                                                                                                  
    EA-I. Knapp: Geomagnetism



    Bib. 31      |      Vol_I-0849                                                                                                                  
    EA-I. Knapp: Geomagnetism

    309. See Terr.Magn . vol.42, p.333, 1937.

    310. H. F. Johnston. “MacGregor Arctic Expedition, 1937-38,” Terr.Magn . vol.42,

    p.315, 1937. See also same journal vol.43, p.244, 1938. For

    summarized results see item 6/114 (vol.8).

    311. Louise A. Boyd. The Coast of North-East Greenland . N.Y., 1948. Amer.

    Geogr.Soc. Spec.Publ. no.30. Especially p.325.

    312. B. Trumpy and Rolf Kjaer. A Magnetic Survey of Norway made 1938-41 by

    Magnetisk Byrå, Bergen and Norges Sjökartverk, Oslo . 1945.

    Jordmagnetiske Publikasjoner Nr.1.

    313. See items 6/25, 112-15 (vol.8); 314.

    313a. See item 6/24-5, 112-5 (vol.8).

    314. R. Glenn Madill. “Declination results at Canadian statrons north of

    latitude 60° N, 1938-47,” Ottawa.Dom.Astr.Obs. Publ . vol.11, p.343, 1949.

    314a. Larsen. H.A. H.A. Larsen. “Reactions of the compasses of the R.C.M.P. Schooner

    St. Roch, when navigating arctic waters,” Navigation vol.1, p.87, 1946.

    315. Ia. Ia. Gekkel. “O deviatsii magnitnykh kompasov v arktike.” (On the

    deviation of the magnetic compass in the Arctic.) Problemy Ark. no.3,

    pp.65-80, 1937. Russian, with English summary. (Cf. item 42)

    Includes chart of horizontal intensity.

    315a. K. G. Bronshtein. “Use of the magnetic compass in the Arctic,” Severnyi

    Morskoi Put (See item 305). Pt.8, pp.67-72. In Russian.

    315b. A. P. Nikolskii. “Sutochnyi Khod vozmushchennosti magnitnogo polia v

    vysokikh shirotakh.” (Diurnal cycle of disturbances of the magnetic

    field in high latitudes.) Problemy Ark. no.4, pp.5-43, 1938. In

    Russian. Has bibliography of 20 references. (Cf. item 42) See also

    items 281a; 317.

    316. Leiv. Harang. “Pulsations in the terrestrial magnetic records at high

    latitude stations,” Geofysiske Publikasjoner vol.13, no.3, 1942.

    See also item 278.

    316a. See item 6/339-56 (vol.5).

    317. E. O. Hulburt. “Some suggestions for auroral and magnetic observations

    in polar regions,” Amer.Geophys.Un. Trans . 1930, p.188. See also

    item 315b.

    318. A. B. Whatman. “Observations made on the ionosphere during operations

    in Spitsbergen in 1942-43,” Phys.Soc.Lond. Proc . B, vol.62, p.307,

    1949. For an earlier example of similar studies see Discovery vol.18,

    pp.3, 35, 1937.



    Bib. 31a      |      Vol_I-0850                                                                                                                  
    EA-I. Knapp: Geomagnetism

    319. J. Egedal, Johannes Olsen and V. Laursen. Denmark, Report on Magnetic

    Work in the Years 1939-47 . Wash.,D.C., G.P.O., 1948, p.11.

    International Association of Terrestrial Magnetism and Electricity.

    Reprints of National and Committee Reports and Scientific Communications…

    Prepared for Distribution at the Oslo Assembly.

    319a. J.Geophys.Res. vol.55, p.104, 1950.



    Bib. 32      |      Vol_I-0851                                                                                                                  
    EA-Knapp: Geomagnetism

    320. R. G. M[adill] . “Magnetic observatories in the Canadian Arctic. National

    Research Council of Canada,” Canadian Geophys.Bull . vol.3, no.1,

    p.22, 1949. Other numbers of this quarterly contain reports of

    other recent magnetic work and related bibliographies.

    320a. Results [?] of Observations Made by the Polar Magnetic Observatories in 1938 .

    Leningrad, 1941. Leningrad.Arkticheski Nauchyi-Issled. Inst. Trudy

    vol.180. Russian text; tables Russian and French. (Cf. item 276).

    Four observatories covered: Matochkin Shar, Dickson Island, Bay

    Tikhaya, and Jekman Island. The last-named was a temporary station

    operated for several months, in the Nordenskiöld Archipelago.

    321. Victor Vacquier and James Affleck. “A Computation of the average depth to

    the bottom of the [ ?]

    [ ?] earth’s magnetic crust, based on a statistical study of

    local magnetic anomalies,” Amer.Geophys.Un Trans . 1941, p.446.

    322. A. G. McNish. “Physical representations of the geomagnetic field,” Ibid .

    1940, p.287.

    323. Sydney Chapman. “Notes on isomagnetic charts,” Terr.Magn . vol.45, p.433,

    1940; vol.46, pp.7, 163, 1941; vol.47, pp. 1, 115, 1942. See esp.

    [ ?] vol.46, pp.20-21. Discussed by W. M. Mitchell in Nature , Lond.

    vol.150, p.439, 1942.

    324. G. Sidney Stanton. “Let’s Simplify navigation,” Flying, Chicago, vol.37,

    p.32, July, 1945. Shows magnetic meridians in the North American

    Arctic. For a similar chart of another area see item 254.

    325. [?] U.S.S.R. Glavnoe Upravlenie Severnogo Morskogo Puti (Northern Sea Route

    Administration). Arkticheskii Nauchno-Issledovatelskii Institut

    (Arctic Study and Investigating Institute). Ekspeitsiia na Semolete

    [ ?] SSSR-N-169 v Reion Poliusa Nedostupnosti . (Expedition

    of aircraft “USSR N 169” in area of pole of inaccessibility). Moscow,

    1946. Some of the conclusions are summarized in item 326a.

    326. B. P. Veinberg. “Symmetry of the magnetic field in polar regions,” Akad.Nauk

    Comptes Rendus (Doklady) vol.31, no.2, p.117, 1941. This study dis–

    cussed in item 326a.

    326a. Mikhail Ostrekin. “V severnom polusharii vozmozhen vtoroi magnitnyi polius.”

    (Second magnetic pol ar e in Northern Hemisphere). Prinoda , Moscow, no.10,

    p.60, Oct., 1947. English translation in Australian J.Sci . vol.10,

    p.107, 1948. The Stefansson Library, New York City, also has a

    translation.

    327. D. C. McKinley. “The arctic flights of Aries,” Geogr.J Geogr.J . vol.107, p.90, 1946.

    328. Great Britain. Royal Air Force. Empire Air Navigation School. North Polar

    Flights of “Aries.” 1947. 10 pts. Its Report no.45/24. (Processed)

    See pt.5, “Compasses and terrestrial magnetism,” and pt.10,

    “Bibliography.” See also item 327.



    Bib. 33      |      Vol_I-0852                                                                                                                  
    EA-I. Knapp: Geomagnetism

    329. Frank O. Klein. “Preliminary magnetic chart for 1947,” Amer.Geophys.Un.

    Trans . vol.30, p.221, 1949. An isogonic chart of the Beaufort Sea

    to latitude 85°.

    330. E. O. Schonstedt and H. R. Irons. “Airborne magnetometer for [ ?] determining

    all magnetic components,” Ibid . vol.30, p.469, 1949. Title only.

    See also Science vol. 110, p. 377, 1949.

    331. M. E. Ostrekin. “Novye magnityne i ionosfernye stantsii v Sovetskoi

    Arktike.” (The new magnetic and ionospheric stations in the Soviet

    Arctic.) Problemy Ark . no.2, p.120, 1944. (Cf. item 42)

           

    David G. Knapp

    The Search for the North Magnetic Pole



    Unpaginated      |      Vol_I-0853                                                                                                                  
    EA-I. (R. Glenn Madill)

    THE SEARCH FOR THE NORTH MAGNETIC POLE

           

    CONTENTS

    Page
    Nature of the Magnetic Pole 2
    Earlier Determination of the Magnetic Pole 3
    Modern Studies 5
    Observations During 1947 7
    Determination of the Position of the Magnetic Pole 9
    Work Still Remains to be Done 11



    Unpaginated      |      Vol_I-0854                                                                                                                  
    EA-I. Madill; The Search for the North Magnetic Pole

           

    LIST OF FIGURES

    Page
    Fig. 1 Chart of magnetic meridians for a portion of northern

    Canada constructed from recent Canadian declination

    observations by the Dominion Observatory, Ottawa
    10-a



    001      |      Vol_I-0855                                                                                                                  
    EA-I. (R. Glenn Madill)

           

    THE SEARCH FOR THE NORTH MAGNETIC POLE

            On June 2, 1931, Ross fixed the British flag to a spot on Cape Adelaide

    Regin e a , Boothia Peninsula, and took possession of the North Magnetic Pole in

    the name of Great Britain and King William the Fourth. The spot was a fixed

    geographical point — 70°5′ N. Latitude, 96°46′ W. Longitude — about which

    the Magnetic Pole was perpetually moving. During Ross’ observations, extend–

    ing over a 24-hour period, the Pole was moving within an area whose diameter

    was of the order of 16 miles. Ross arrived at the North Magnetic Pole on

    foot having walked from his base at Victory Harbour about 100 miles away.

            On May 3, 1904, Amundsen reached a point on Boothia Peninsula apparently

    about 20 miles from the Magnetic Pole. He had traveled by sledge from

    Gjoa Haven, King William Island, some 150 miles distant. The Pole at that

    time was computed to be in 70°30′ N. latitude, and 95°30′ W. longitude,

    about 40 miles northeast of Ross’ position. Amundsen established at Gjoa Haven

    a temporary magnetic observatory, which operated from November 1903 to May 1905,

    and furnished control to field observations made during a magnetic survey of

    parts of King William Island and Boothia Peninsula. This long series of

    magnetic measurements showed, among other things, that the Pole could be

    displaced in a north-south direction by a range of 150 miles. Had Amundsen

    been able to surround the Magnetic Pole area by magnetic stations, his site

    for the mean position of the Pole might have been somewhat different.



    002      |      Vol_I-0856                                                                                                                  
    EA-I. Madill: Search for Magnetic Pole

            On August 22, 1947, Serson and Clark landed on the shore of Allen Lake,

    northeastern Prince of Wales Island, from a Royal Canadian Air Force Canso

    having flown from Cambridge Bay, Victoria Island, about 325 miles away. The

    North Magnetic Pole was probably within 10 miles of them before receding on

    its uneasy course. The observations at Allen Lake offered evidence that the

    Magnetic Pole described some sort of a rough orbit whose radius was of the

    order of 25 miles on a magnetically quiet and 50 miles on a magnetically

    disturbed day. The results for this station appear in Table I.

            Nature of the Magnetic Pole . The Magnetic Pole may be defined as an

    area rather than a precise point. There the earth’s magnetic field is vertical

    and the dipping needle points towards the center of the earth. The compass

    needle is useless since the horizontal force required to hold it in its

    direction has vanished. The daily fluctuations in position of the Pole result

    from deformations in the magnetic field caused by solar activity operating in

    the earth’s upper atmosphere, while the secular or long-term movement has its

    origin within the earth. The daily fluctuations are limited to a movement

    about a fixed geographical point which represents the mean position of the

    Pole at the time. It is understood, therefore, when a position for the

    Magnetic Pole is indicated, it represents the mean center of an area at a

    par [?] t cular epoch.

            There exist throughout Canada centers of local attraction where the

    earth’s field is distorted by the presence of magnetic materials in either the

    rocks or the overburden. The attraction at some of these centers has sufficient

    strength to create local poles. The effect of local poles is quickly dissipated

    in a comparatively short distance form the area. The Canadian Arctic is not

    free from this condition. There are, for example, known areas of local

    002a      |      Vol_I-0857                                                                                                                  

    TABLE 1

    Preliminary values of declination (D) inclination (I) horizontal intensity (H) total intensity

    (F) and distance (R) from magnetic pole according to local mean time (L.M.T) at

    Allen Lake*, northeastern Prince of Wales Island latitude 73° 41′N. longitude 98° 26′W.
    DATE L.M.T D I H F R
    1947 H m ° ° gammas gammas miles
    Aug. 22 16 43 108 58 89 35 422 58177 50