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Evidence for a new geomagnetic reversal from lava flows in Idaho: Discussion of short polarity reversals in the Brunhes and late Matuyama polarity chrons Evidence for a new geomagnetic reversal from lava flows in Idaho: Discussion of short polarity reversals in the Brunhes and late Matuyama polarity chrons

K-Ar ages and paleomagnetic data for basalt samples from a new core hole (site E) at the Idaho National Engineering Laboratory (INEL) indicate that the age of the reversed polarity event recorded in Snake River Plain lavas is older than 465±50 ka (1000 years before present) reported previously by Champion et al. (1981). Nine basalt flows, eight with normal polarity and one with reversed...
Authors
D.E. Champion, M. A. Lanphere, M. A. Kuntz

New trend- trigonometric model for interpolation and prediction of the geomagnetic field utilizing the new DGRF models New trend- trigonometric model for interpolation and prediction of the geomagnetic field utilizing the new DGRF models

At the IUGG Assembly at Vancouver during August 1987 new definitive geomagnetic reference field (DGRF) models to degree 10 for 1945, 1950, 1955, and 1960 were adopted by IAGA. Before these new DGRF models were accepted, the author developed a trend and trigonometric model (old trig model) based on the models IGRF 1945, IGRF 1950, IGRF 1955, IGRF 1960, DGRF 1965, DGRF 1970, DGRF 1975...
Authors
L.R. Alldredge

Range indices of geomagnetic activity Range indices of geomagnetic activity

The simplest index of geomagnetic activity is the range in nT from maximum to minimum value of the field in a given time interval. The hourly range R was recommended by IAGA for use at observatories at latitudes greater than 65??, but was superceded by AE. The most used geomagnetic index K is based on the range of activity in a 3 h interval corrected for the regular daily variation. In...
Authors
W.F. Stuart, A.W. Green

Landslides, Floods, and Marine Effects of the Storm of January 3-5, 1982, in the San Francisco Bay Region, California Landslides, Floods, and Marine Effects of the Storm of January 3-5, 1982, in the San Francisco Bay Region, California

A catastrophic rainstorm in central California on January 3-5,1982, dropped as much as half the mean annual precipitation within a period of about 32 hours, triggering landslides and floods throughout 10 counties in the vicinity of the San Francisco Bay. More than 18,000 of the slides induced by the storm transformed into debris flows that swept down hillslopes or drainages with little...
Authors
Gerald F. Wieczorek
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