Publications
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Preliminary catalog of earthquakes in northern Imperial Valley, California, January 1, 1977 to March 31, 1977
The northern section of the Imperial Valley region in Southern California is an area of known geothermal resources and an area of high seismicity. To study in detail the relationship between geothermal areas and earthquakes, the U.S. Geological Survey has been monitoring seismicity in the Imperial Valley with a sixteen station network since 1973. Six new stations were added to the network in Novem
Authors
Madeline Schnapp, Gary S. Fuis
Playback Station #2 for Cal Net and 5-day-recorder tapes
A second system (Playback Station #2) has been set up to play back Cal Net 1" tapes and 5-day-recorder 1/2" tapes. As with the first playback system (Playback Station #1) the tapes are played back on a Bell and Howell VR3700B tape deck and the records are written out on a 16-channel direct-writing Siemens "0scillomink." Separate reproduce heads, tape guides, and tape tension sensor rollers are req
Authors
Jerry P. Eaton
Proceedings of Conference IV: the use of volunteers in the Earthquake Hazards Reduction Program, convened under the auspices of National Earthquake Hazards Reduction Program, 2-3 February, 1978, Menlo Park, California
There are tens of thousands of people in the United States who could
play an important voluntary role in reducing earthquake hazards and are
probably willing to do so. Under the Earthquake Hazard Reduction Act of
1977 the Federal government is significantly increasing its effort "to
reduce the risk of life and property from future earthquakes in the
United States through the establishment and main
Five-day recorder seismic system
The 10-day recorder seismic system used by the USGS since 1965 has been modified substantially to improve its dynamic range and frequency response, to decrease its power consumption and physical complexity, and to make its recordings more compatible with other NCER systems to facilitate data processing. The principal changes include:
1. increasing tape speed from 15/160 ips to 15/80 ips (red
Authors
Ed Criley, Jerry P. Eaton, Jim Ellis
FORTRAN programs for calculating nonlinear seismic ground response in two dimensions
The programs described here were designed for calculating the nonlinear seismic response of a two-dimensional configuration of soil underlain by a semi-infinite elastic medium representing bedrock. There are two programs. One is for plane strain motions, that is, motions in the plane perpendicular to the long axis of the structure, and the other is for antiplane strain motions, that is motions par
Authors
W. B. Joyner
Estimation of ground motion parameters
Strong motion data from western North America for earthquakes of magnitude greater than 5 are examined to provide the basis for estimating peak acceleration, velocity, displacement, and duration as a function of distance for three magnitude classes. Data from the San Fernando earthquake are examined to assess the effects of associated structures and of geologic site conditions on peak recorded mot
Authors
David M. Boore, Adolph A. Oliver, Robert A. Page, William B. Joyner
Historic ground failures in Northern California triggered by earthquakes
A major source of earthquake-related damage and casualties in northern California has been ground failures generated by the seismic shaking, including landslides, lateral spreads, ground settlement, and surface cracks. The historical record shows that, except for offshore shocks, the geographic area affected and the quantity and general severity of ground failures increase markedly with Richter ma
Authors
T. Leslie Youd, Seena N. Hoose
The effects of the α‐β phase transformation on the creep properties of hydrolytically‐weakened synthetic quartz
Nine rectangular prisms of hydro‐thermally‐grown synthetic quartz crystals with 900 atomic ppm H+ were loaded in compression at 1400 bars stress and temperatures between 403 and 764°C. The a and c directions were at 45° to the compression direction, and the slip system appears to operate over the entire range of temperatures. The strain vs. time curves were sigmoidal in shape; an incubation stage
Authors
Stephen H. Kirby
Mechanical twinning in diopside Ca(Mg,Fe)Si2O6: Structural mechanism and associated crystal defects
iopside twins mechanically on two planes, (100) and (001), and the associated macroscopic twinning strains are identical (Raleigh and Talbot, 1967). An analysis based on crystal structural arguments predicts that both twin mechanisms involve shearing of the (100) octahedral layers (containing Ca2+, Mg2+ and Fe2+ ions) by a magnitude of c/2. Small adjustments or shuffles occur in the adjacent layer
Authors
Stephen H. Kirby, J.M. Christie
Late Quaternary depositional history, Holocene sea-level changes, and vertical crustal movement, southern San Francisco Bay, California
Sediments collected for bridge foundation studies at southern San Francisco Bay, Calif., record estuaries that formed during Sangamon (100,000 years ago) and post-Wisconsin (less than 10,000 years ago) high stands of sea level. The estuarine deposits of Sangamon and post-Wisconsin ages are separated by alluvial and eolian deposits and by erosional unconformities and surfaces of nondeposition, feat
Authors
Brian F. Atwater, Charles W. Hedel, Edward J. Helley
Application of linear statistical models of earthquake magnitude versus fault length in estimating maximum expectable earthquakes
Correlation or linear regression estimates of earthquake magnitude from data on historical magnitude and length of surface rupture should be based upon the correct regression. For example, the regression of magnitude on the logarithm of the length of surface rupture L can be used to estimate magnitude, but the regression of log L on magnitude cannot. Regression estimates are most probable values,
Authors
Robert K. Mark