Publications
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DEFORESTATION AND LANDSLIDES IN YUNNAN, CHINA.
Landslides historically have caused severe erosion problems in the Xiao River drainage region of northeastern Yunnan Province, China, that hence resulted in serious economic and social consequences. Owing to monsoonal storms of high rainfall intensity, the erosion potential is high in this mountainous, seismically active region. Landslides transported large quantities of materials into the ravines
Authors
Gerald F. Wieczorek, Jishan Wu, Tianchi Li
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 geomagnetic history
Authors
E. A. Mankinen, E.E. Larson, C. S. Grommé, M. Prevot, R. S. Coe
Landslides of Eastern North America
No abstract available.
Authors
Arthur P. Schultz, C. S. Southworth
Real-time landslide warning during heavy rainfall
A real-time system for issuing warnings of landslides during major storms is being developed for the San Francisco Bay region, California. The system is based on empirical and theoretical relations between rainfall and landslide initiation, geologic determination of areas susceptible to landslides, real-time monitoring of a regional network of telemetering rain gages, and National Weather Service
Authors
D. K. Keefer, R. C. Wilson, R. K. Mark, E. E. Brabb, W. M. Brown, S. D. Ellen, E. L. Harp, G. F. Wieczorek, C.S. Alger, R.S. Zatkin
Some effects of quiet geomagnetic field changes upon values used for main field modeling
The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the average of all values during the year. For H these differences were 2-3 gammas, f
Authors
W.H. Campbell
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-field mod
Authors
N. W. Peddie, A. K. Zunde
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 that future d
Authors
D. Thompson, J.C. Cain
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 Reference
Authors
N. W. Peddie, A. K. Zunde
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 magnetizati
Authors
E.R. Benton, L.R. Alldredge
Rainfall, ground-water flow, and seasonal movement at Minor Creek landslide, northwestern California: Physical interpretation of empirical relations
Simple ground-water flow analyses can clarify complex empirical relations between rainfall and landslide motion. Here we present detailed data on rainfall, ground-water flow, and repetitive seasonal motion that occurred from 1982 to 1985 at Minor Creek landslide in northwestern California, and we interpret these data in the context of physically based theories. We find that landslide motion is clo
Authors
R. M. Iverson, J. J. Major
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 is the Ca
Authors
L.R. Alldredge
Current loops fitted to geomagnetic model spherical harmonic coefficients.
One hundred-sixty circular current loops with radial axes were fitted by least squares to the 899 spherical harmonic coefficients of a 29th degree model. In the first case, the parameters that were fitted for each loop were the normalized magnetic moment, the distance from the center of the Earth to the current element, the colatitude and E. longitude of the loop axis, and one-half of the central
Authors
L.R. Alldredge