Publications
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Seismic evidence for active magmatic underplating beneath the Basin and Range Province, western United States
Near-vertical and wide-angle seismic reflection data provide evidence for the presence of a magma body at the base of the crust beneath Buena Vista Valley in northwestern Nevada. The seismic response of this hypothesized magma body is characterized by high-amplitude, near-vertical P wave reflections and a comparably strong P-to-S converted phase. The magma body, referred to here as the Buena Vista
Authors
Craig M. Jarchow, George A. Thompson, Rufus D. Catchings, Walter D. Mooney
Deformation from 1973 to 1987 in the epicentral area of the 1959 Hebgen Lake, Montana, earthquake (Ms = 7.5)
A 40‐km aperture trilateration network centered on the 1959 Hebgen Lake earthquake epicenter has been surveyed in 1973, 1974, 1976, 1978, 1981, 1984, and 1987. The deformation inferred from those surveys is described roughly by a uniaxial, 0.266 ± 0.014 μstrain/yr, N15°E ± 1°extension that is uniform in both time and space. That extension is orthogonal to the strike (N78°W ± 5°) of the 1959 ruptur
Authors
James C. Savage, Michael Lisowski, W. H. Prescott, A. M. Pitt
Deformation from 1973 through 1991 in the epicentral area of the 1992 Landers, California, Earthquake (Ms = 7.5)
Deformation of a 50 × 60 km trilateration network that spans the epicenter of the 1992 Landers earthquake(Ms = 7.5) was measured by seven surveys over the 19 years preceding the earthquake. Three moderate earthquakes (1979 Homestead Valley, Ms = 5.6; 1986 North Palm Springs, Ms = 6.0; and 1992 Joshua Tree, Ms = 6.1) occurred within the network during those 19 years. Here we use geodetic and seismi
Authors
James C. Savage, Michael Lisowski, M. Murray
On the estimation of site-dependent response spectra
No abstract available.
Authors
Roger D. Borcherdt
Klamath Falls earthquakes, September 20, 1993 — Including the strongest quake ever measured in Oregon
Earthquakes struck the Klamath Falls area on Monday night, September 20, 1993, resulting in two deaths and extensive damage. The quakes were felt as far away as Coos Bay to the west, Eugene to the north, Lakeview to the east, and Chico, California, to the south. A foreshock recorded at 8:16 p.m. had a Richter magnitude of 3.9. The first of two main shocks, measuring 5.9 on the Richter scale, rumbl
Authors
T. J. Wiley, David R. Sherrod, David K. Keefer, Anthony Qamar, Robert L. Schuster, James W. Dewey, Matthew A. Mabey, Gerald L. Black, Ray Wells
Galileo observations of Post-Imbrium lunar craters during the first Earth-Moon flyby
Copernican‐age craters are among the most conspicuous features seen on the far side and western limb of the Moon in the Galileo multispectral images acquired in December 1990. Among the new morphologic observations of far‐side craters are bright rays, continuous ejecta deposits, and dark rings associated with probable impact‐melt veneers. These observations suggest that the mapped age assignments
Authors
Alfred S. McEwen, Lisa R. Gaddis, Gerhard Neukum, Harald Hoffman, Carle M. Pieters, James W. Head
Site response estimates in Salt Lake Valley, Utah, from borehole seismic velocities
The general correlation of Salt Lake Valley sites located on soft, saturated unconsolidated silty and clayey deposits (that is, deposits with low S-wave velocity) with high seismic amplification at the ground surface motivated our investigation of the relationship between the P- and S-wave seismic velocity (Vp and Vs) of these units and their corresponding observed site response. We found that low
Authors
R. A. Williams, K. W. King, John Tinsley
Landslides triggered by the storm of November 3-5, 1985, Wills Mountain Anticline, West Virginia and Virginia: Chapter C in Geomorphic studies of the storm and flood of November 3-5, 1985, in the upper Potomac and Cheat River basins in West Virginia and V
More than 3,000 landslides were triggered by heavy rainfall in the central Appalachian Mountains of West Virginia and Virginia, November 3-5, 1985. These landslides provided the opportunity to study spatial controls on landslides, magnitude and frequency of triggering events, and the effects of landslides on flood-induced geomorphic change. The study area consists of parts of the Wills Mountain an
Authors
Robert B. Jacobson, John P. McGeehin, Elizabeth D. Cron, Carolyn E. Carr, John M. Harper, Alan D. Howard
The Parkfield prediction fallacy
The Parkfield earthquake prediction is generally stated as a 95% probability that the next moderate earthquake there should occur before January 1993. That time limit is based on a two-sided 95% confidence interval. Because at the time of the prediction (1985) it was already clear that the earthquake had not occurred prior to 1985, a one-sided 95% confidence interval would have been more appropria
Authors
James C. Savage
Rainfall-threshold conditions for landslides in a humid-tropical system
Landslides are triggered by factors such as heavy rainfall, seismic activity, and construction on hillslopes. The leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall. A rainfall threshold for rainfall-triggered landsliding is delimited by 256 storms that occurred between 1959 and 1991 in the central mountains of Puerto Rico, where mean annual rainfall is close to or in
Authors
Matthew C. Larsen, Andrew Simon
Broad trends in geomagnetic paleointensity on Hawaii during Holocene time
Paleointensity determinations have been obtained from 22 basaltic lava flows on the island of Hawaii using the Thelliers' method. Radiocarbon dating indicates that these flows erupted at intervals ranging from about 200 to 1000 years, and results of the experiments provide an estimate of broad trends in geomagnetic paleointensity during Holocene time in the vicinity of Hawaii. Most of the samples
Authors
Edward A. Mankinen, Duane E. Champion
GIS mapping of earthquake ground shaking in San Francisco, California
Severe earthquakes of the last decade in Mexico, Armenia, and the United States have reemphasized the importance of local geologic site conditions in estimating damage and consequent losses. Recent advances in geographic information system (GIS) technology have created new opportunities for maintaining and integrating extensive spatial databases for applications in seismic hazard analysis. Ground
Authors
S.A. King, Anne S. Kiremidjian, Roger D. Borcherdt, Carl M. Wentworth