Publications

A total of 1,075 earthquakes occurred in the Pahute Mesa area with 2.5≤ML≤4.9 during the period October 28, 1975, to June 28, 1976. The majority of these earthquakes are aftershocks of the nuclear events, Kasseri, Inlet, Muenster, Fontina, Cheshire, Estuary, Colby, and Pool (5.8≤ML≤6.3). Smaller nuclear events (ML≤5.5) on Rainier Mesa and Yucca Flat detonated in the same time period did not trigge

The seismograph stations listed in this catalog were established over the period January 1964 through June 1976 in support of the Energy Research and Development Administration, Nevada (ERDA/NV) underground weapons testing program at the Nevada Test Site (NTS), central Nevada, and Amchitka, Alaska. For station listings before 1964 see Coast and Geodetic Survey publication, "Seismic Data Summary Nu

The United States Geological Survey (USGS), Branch of Earthquake Hazards (BEH), Las Vegas, Nevada has provided ERDA, Nevada Operations Office, with seismic monitoring support to the underground nuclear weapons test program conducted at the Nevada Test Site (NTS) since September 1961. Activities from September 15, 1961 to September 13, 1963 are summarized in the report, "Seismic Dats Summary Nuclea

The program described here was designed for calculating the nonlinear seismic response of a system of horizontal soil layers underlain by a semi-infinite elastic medium representing bedrock. Excitation is a vertically incident shear wave in the underlying medium. The nonlinear hysteretic behavior of the soil is represented by a model consisting of simple linear springs and Coulomb friction element

The USGS telemetered seismic system was intended primarily to record small to moderate earthquakes (magnitude 0 to 4) at distances of a few km to several hundred km. Its frequency response is such that the recorded background noise at a moderately quite Coast Range site has a relatively flat 'record' spectrum from about 1/3 Hz to about 20 Hz. With the system magnification set so that the backgroun

Seismic wave velocities (compressional and shear) are important parameters for estimating the seismic response characteristics of various geologic units when subjected to strong earthquake ground shaking. Seismic velocities of various units often show a strong correlation with the amounts of damage following large earthquakes and have been used as a basis for certain types of seismic zonation stud

The epicenter of the Hollister earthquake (ML = 5.1) of November 28, 1974, is located near the center of an 81‐line trilateration network which has been surveyed annually since 1971. Five lines in the neighborhood of the epicenter were surveyed just 2 days before the earthquake, and two other lines nearby were surveyed 48 days earlier. Although some of these measurements suggest a possible preeart

Precise distance measurements of a 10×25 km 15‐station trilateration network that spans the San Andreas fault west of Palmdale, California, have been repeated annually in the period 1971–1975. The network appears to be deforming under simple uniform tensor shear of about 0.21±0.03 μstrain/yr with the direction of maximum right‐lateral shear parallel to the local strike of the San Andreas fault. Co

Measurements of ground motion generated by nuclear explosions in Nevada have been completed for 99 locations in the San Francisco Bay region, California. The recordings show marked amplitude variations in the frequency band 0.25 to 3.0 Hz that are consistently related to the local geological conditions of the recording site. The average spectral amplifications observed for vertical and horizontal

Relatively rigid plates making up the outer 50 to 100 km of the Earth are steadily separating from one another along narrow globe-circling zones of submarine volcanism, the oceanic spreading centers. Continuity requires that the viscous underlying material rise beneath spreading centers and accrete onto the steadily diverging plates. It is likely that during the rise the viscosity changes systemat

Seismic wave velocities (compressional and shear) are important parameters for determining the seismic response characteristics of various geologic units when subjected to strong earthquake ground shaking.Seismic velocities of various units often show a strong correlation with the amounts of damage following large earthquakes and have been used as a basis for certain types of seismic zonation stud

A four-level downhole array of three-component instruments was established on the southwest shore of San Francisco Bay to monitor the effect of the sediments on low-amplitude seismic ground motion. The deepest instrument is at a depth of 186 meters, two meters below the top of the Franciscan bedrock. Earthquake data from regional distances (29 km ≤ Δ ≤ 485 km) over a wide range of azimuths are com