Publications
Geomagnetism publications.
Fact Sheets
Fact Sheets
1-2 page plain language summaries of geomagnetism topics and research
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The geomagnetic jerk of 1969 and the DGRFs The geomagnetic jerk of 1969 and the DGRFs
Cubic spline fits to the DGRF/IGRF series indicate agreement with other analyses showing the 1969-1970 magnetic jerk in the h ??12 and g ??02 secular change coefficients, and agreement that the h ??11 term showed no sharp change. The variation of the g ??01 term is out of phase with other analyses indicating a likely error in its representation in the 1965-1975 interval. We recommend...
Authors
D. Thompson, J.C. Cain
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, August 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, June 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, June 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, May 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, May 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, March 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, February 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, February 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, January 1987 Preliminary geomagnetic data, College Observatory, Fairbanks, Alaska, January 1987
No abstract available.
Authors
John B. Townshend, R. V. O’Connell, L.Y. Torrence
Localized sudden changes in the geomagnetic secular variation. Localized sudden changes in the geomagnetic secular variation.
There is much debate as to whether there was a worldwide geomagnetic jerk in 1969 or 1970. It is agreed that there was an unusual sharp change in the secular variation in the east component, Y, in Europe at that time. This note points out how a localized sudden change in the secular variation pattern of one component in Europe can occur without having any large worldwide effects in any...
Authors
L.R. Alldredge
The Steens Mountain (Oregon) geomagnetic polarity transition: 3. Its regional significance The Steens Mountain (Oregon) geomagnetic polarity transition: 3. Its regional significance
Study of the variations of direction and intensity of the geomagnetic field as recorded by the Miocene lava flows on Steens Mountain, southeastern Oregon, has resulted in a detailed description of total field behavior during a reversal in polarity. In addition to information about the polarity reversal itself, the detailed paleomagnetic record includes several thousand years of...
Authors
E. A. Mankinen, E.E. Larson, C. S. Grommé, M. Prevot, R. S. Coe
On predicting changes in the geomagnetic field On predicting changes in the geomagnetic field
The present method of using constant secular variation rates to forecast magnetic components at a given site or to forecast spherical harmonic coefficients is known to be inaccurate. A new predictive method using trend and trigonometric functions fitted to known past values is used to extrapolate for a few years into the future. This provides an improvement over the usual linear...
Authors
L.R. Alldredge
Assessment of models proposed for the 1985 revision of the international geomagnetic reference field Assessment of models proposed for the 1985 revision of the international geomagnetic reference field
Geomagnetic measurements from land, marine and aerial surveys conducted in the years 1945-1964 were used to test the 14 models proposed as additions, for that period, to the series of definitive geomagnetic reference field (DGRF) models. Overall, NASA's 'SFAS' models and the BGS (British Geological Survey) models agree best with these data. Comparisons of the two proposed definitive main...
Authors
N.W. Peddie, A.K. Zunde
A model of geomagnetic secular variation for 1980-1983 A model of geomagnetic secular variation for 1980-1983
We developed an updated model of the secular variation of the main geomagnetic field during 1980 through 1983 based on annual mean values for that interval from 148 worldwide magnetic observatories. The model consists of a series of 80 spherical harmonics, up to and including those of degree and order 8. We used it to form a proposal for the 1985 revision of the International Geomagnetic...
Authors
N.W. Peddie, A.K. Zunde