Publications
Geomagnetism publications.
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Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska: April 1976
The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.
Authors
John B. Townshend, J.E. Papp, M.J. Moorman, C.E. Deadmon, S.P. Tilton
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska: March 1976
The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.
Authors
John B. Townshend, J.E. Papp, M.J. Moorman, C.E. Deadmon, S.P. Tilton
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska: June 1976
The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.
Authors
J.B. Townshend, J.E. Papp, M.J. Moorman, C.E. Deadmon, S.P. Tilton
Pacific geomagnetic secular variation
A smooth field over the central Pacific for a million years indicates a nonuniform lower mantle of the earth.
Authors
Richard R. Doell, A. Cox
Geomagnetic polarity epochs: age and duration of the olduvai normal polarity event
New data show that the Olduvai normal geomagnetic polarity event is represented in Olduvai Gorge, Tanzania, by rocks covering a time span of roughly from 0.1 to 0.2 my and is no older than 2.0 my. Hence the long normal polarity event of this age that is seen in deep-sea sediment cores and in magnetic profiles over oceanic ridges should be called the Olduvai event. The lava from which the Gilsàeven
Authors
C. S. Grommé, R. L. Hay
History of the geomagnetic field
Direct measurements of the direction and strength of the earth's magnetic field have provided a knowledge of the field's form and behavior during the last few hundreds of years. For older times, however, it has been necessary to measure the magnetism of certain rocks to learn what the geomagnetic field was like. For example, when a lava flow solidifies (at temperatures near 1000°C) and cools throu
Authors
Richard R. Doell
Geomagnetic reversals
Although decreasing rapidly, the earth's magnetic field is probably not now reversing.
Authors
A. Cox
Geomagnetic polarity epochs: Nunivak Island, Alaska
New paleomagnetic and potassium-argon dating measurements have been made of basalt flows from Nunivak Island, Alaska, with the following results. (1) The best estimate of the age of the Brunhes/Matuyama polarity epoch boundary is found to be 0.694 m.y. (2) The best estimate of the age of the Gauss/Gilbert boundary is 3.32 m.y. (3) Three normally magnetized flows with ages from 0.93 to 0.88 m.y. ar
Authors
A. Cox, G. B. Dalrymple
Geomagnetic polarity zones for icelandic lavas
Analysis of cores collected from a sequence of lavas in Eastern Iceland has made possible an accurate calculation of the average rate of reversal of the Earth's magnetic field.
Authors
P. Dagley, R.L. Wilson, J. M. Ade-Hall, G.P.L. Walker, S.E. Haggerty, T. Sigurgeirsson, N.D. Watkins, P.J. Smith, J. Edwards, R.L. Grasty
Geomagnetic polarity epochs: new data from Olduvai Gorge, Tanganyika
The lower lava flow of Bed I in Olduvai Gorge, Tanganyika, carries natural remanent magnetization (NRM) having normal polarity. Thermal demagnetization experiments demonstrate the stability of this NRM. Thus the Olduvai geomagnetic polarity event, which was originally named from the upper lava flow in Bed I, is represented in its type locality by two normally magnetized lavas. These lavas have bee
Authors
C. S. Grommé, R. L. Hay
Pliocene geomagnetic polarity epochs
A paleomagnetic and K-Ar dating study of 44 upper Miocene and Pliocene volcanic units from the western United States suggests that the frequency of reversals of the earth's magnetic field during Pliocene time may have been comparable with that of the last 3.6 m.y. Although the data are too limited to permit the formal naming of any new polarity epochs or events, four polarity transitions have been
Authors
G. B. Dalrymple, A. Cox, Richard R. Doell, C. S. Grommé
Geomagnetic polarity epochs: A new polarity event and the age of the Brunhes-Matuyama boundary
Recent paleomagnetic-radiometric data from six rhyolite domes in the Valles Caldera, New Mexico, indicate that the last change in polarity of the earth's magnetic field from reversed to normal (the Brunhes-Matuyama boundary) occurred at about 0.7 million years ago. A previously undiscovered geomagnetic polarity event, herein named the "Jaramillo normal event," occurred about 0.9 million years ago.
Authors
Richard R. Doell, G. B. Dalrymple