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Publications

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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

On regional geomagnetic charts On regional geomagnetic charts

When regional geomagnetic charts for areas roughly the size of the United States were compiled by hand, some large local anomalies were displayed in the isomagnetic lines. Since the late nineteen sixties, when the compilation of charts using computers and mathematical models was started, most of the details available in the hand drawn regional charts have been lost. One exception to this...
Authors
L.R. Alldredge

On the interpretation of the geomagnetic energy spectrum On the interpretation of the geomagnetic energy spectrum

Two recent high-degree magnetic energy spectra, based mostly on MAGSAT data, are compared and found to agree very well out to order and degree n = 15, but the spectrum remains somewhat uncertain for higher degrees. The hypothesis that a primary break in the slope of the spectrum, plotted semi-logarithmically, is due to a transition from dominance by core sources to dominance by crustal
Authors
E.R. Benton, L.R. Alldredge

System designed for issuing landslide alerts in the San Francisco Bay area System designed for issuing landslide alerts in the San Francisco Bay area

A system for forecasting landslides during major storms has been developed for the San Francisco Bay area by the U.S Geological Survey and was successfully tested during heavy storms in the bay area during February 1986. Based on the forecasts provided by the USGS, the National Weather Service (NWS) included landslide warnings in its regular weather forecasts or in special weather...
Authors
D. Finley

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
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