Publications
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A seismic-refraction profile across the San Andreas, Sargent, and Calaveras faults, west-central California
In 1981, the United States Geological Survey recorded a seismic-refraction profile across the southern Santa Cruz Mountains in west-central California to examine the shallow velocity structure of this seismogenic region. This 40-km-long profile, which consisted of three shotpoints, extended northeastward from near Watsonville, California, to Coyote Lake, crossing the San Andreas, Sargent, and Cala
Authors
Walter D. Mooney, Robert H. Colburn
In situ stress, natural fracture distribution, and borehole elongation in the Auburn Geothermal Well, Auburn, New York
Hydraulic fracturing stress measurements and a borehole televiewer survey were conducted in a 1.6‐km‐deep well at Auburn, New York. This well, which was drilled at the outer margin of the Appalachian Fold and Thrust Belt in the Appalachian Plateau, penetrates approximately 1540 m of lower Paleozoic sedimentary rocks and terminates 60 m into the Precambrian marble basement. Analysis of the hydrauli
Authors
Stephen H. Hickman, John H. Healy, Mark D. Zoback
A general earthquake-observation system (GEOS)
Microprocessor technology has permitted the development of a General Earthquake-Observation System (GEOS) useful for most seismic applications. Central-processing-unit control via robust software of system functions that are isolated on hardware modules permits field adaptability of the system to a wide variety of active and passive seismic experiments and straightforward modification for incorpor
Authors
R. D. Borcherdt, Joe B. Fletcher, E.G. Jensen, G.L. Maxwell, J.R. VanSchaack, R.E. Warrick, E. Cranswick, M.J.S. Johnston, R. McClearn
High-frequency observations and source parameters of microearthquakes recorded at hard-rock sites
We have estimated the source parameters of 53 microearthquakes recorded in July 1983 which were aftershocks of the Miramichi, New Brunswick, earthquake that occurred on 9 January 1982. These events were recorded by local three-component digital seismographs at 400 sps/component from 2-Hz velocity transducers sited directly on glacially scoured crystalline basement outcrop. Hypocentral distances ar
Authors
Edward Cranswick, Robert Wetmiller, John Boatwright
Saudi Arabian seismic-refraction profile: A traveltime interpretation of crustal and upper mantle structure
The crustal and upper mantle compressional-wave velocity structure across the southwestern Arabian Shield has been investigated by a 1000-km-long seismic refraction profile. The profile begins in Mesozoic cover rocks near Riyadh on the Arabian Platform, trends southwesterly across three major Precambrian tectonic provinces, traverses Cenozoic rocks of the coastal plain near Jizan, and terminates a
Authors
Walter D. Mooney, M. E. Gettings, H. R. Blank, J. H. Healy
Geographic variation in ground shaking as a function of changes in near-surface properties and geologic structure near Los Angeles, California
No abstract available.
Authors
A. M. Rogers, Ladislaus C. Tinsley, Roger D. Borcherdt
Deformation in the White Mountain seismic gap, California-Nevada, 1972-1982
A 100×40 km trilateration network extending from Bishop, California, to near Hawthorne, Nevada, crosses the east end of the Long Valley caldera, site of renewed magma inflation in the 1979–1980 interval, and spans most of the White Mountain seismic gap. The network was surveyed in 1972, 1973, 1976, 1979, 1980, and 1982. The 1980 survey may be contaminated by a scale error. In addition, leveling su
Authors
James C. Savage, Michael Lisowski
Earthquake swarm in Long Valley caldera, California, January 1983: Evidence for dike inflation
The 1982–1983 deformation observed by trilateration and leveling surveys across the Long Valley caldera is apparently related to the 8.5‐km‐long by 8‐km‐deep vertical rupture surface defined by the January 1983 earthquake swarm that occurred in the south moat of the caldera. The observed deformation can be explained as follows. In late 1982, 0.03 km3 of magma was injected into a dike that dips 30°
Authors
James C. Savage, R.S. Cockerham
Regional deformation near Palmdale, California, 1973-1983 (USA)
The Tehachapi trilateration network spans the intersection of the San Andreas and Garlock faults in southern California in the “Big Bend” region of the San Andreas fault. Analysis of data from 1973–1983 shows strain differences between the northwest and southeast regions of the network and slip at depth on both faults. The Palmdale network, spanning the San Andreas fault entirely within the Tehach
Authors
N.E. King, James C. Savage
A comparative ground response study near Los Angeles using recordings of Nevada nuclear tests and the 1971 San Fernando earthquake
A comparative ground response study at sites in the Los Angeles region is based on the extensive strong-motion data set recorded in the 1971 San Fernando earthquake and 159 three-component recordings of distant nuclear tests in Nevada. Amplitude spectral ratios computed for the nuclear test data over those frequency bands for which there is an adequate signal-to-noise ratio provide statistically s
Authors
A. M. Rogers, Roger D. Borcherdt, P. A. Covington, D. M. Perkins
On recent advances in strong-motion data acquisition capabilities
No abstract available.
Authors
Roger D. Borcherdt
A seismic refraction study of the Oregon Cascades
A 275‐km‐long reversed refraction profile in the Oregon Cascades, two shallow earthquakes of magnitude 5 in southern Washington, a shallow earthquake of magnitude 4.6 in northern California, and a previously published analysis of the Bouguer gravity field are used to develop a crustal P wave velocity model for the Oregon Cascades. Travel time analysis of the refraction profile indicates a crustal
Authors
Donald S. Leaver, Walter D. Mooney, W. M. Kohler