scholarly journals Basic data features and results from a spatially dense seismic array on the San Jacinto fault zone

2015 ◽  
Vol 202 (1) ◽  
pp. 370-380 ◽  
Author(s):  
Yehuda Ben-Zion ◽  
Frank L. Vernon ◽  
Yaman Ozakin ◽  
Dimitri Zigone ◽  
Zachary E. Ross ◽  
...  
Keyword(s):  
Fault Zone ◽  
Seismic Array ◽  
Basic Data ◽  
San Jacinto Fault ◽  
San Jacinto Fault Zone ◽  
Dense Seismic Array

High-resolution imaging of the San Jacinto fault zone with a dense seismic array and local seismic noise

2015 ◽  
Vol 138 (3) ◽  
pp. 1764-1764 ◽  
Author(s):  
Philippe Roux ◽  
Albanne Lecointre ◽  
Ludovic Moreau ◽  
Michel Campillo ◽  
Yehuda Ben-Zion ◽  
...  
Keyword(s):  
High Resolution ◽  
Fault Zone ◽  
Seismic Noise ◽  
Seismic Array ◽  
High Resolution Imaging ◽  
San Jacinto Fault ◽  
San Jacinto Fault Zone ◽  
Resolution Imaging ◽  
Dense Seismic Array

A re-examination of historic earthquakes in the San Jacinto fault zone, California

1991 ◽  
Vol 81 (6) ◽  
pp. 2289-2309
Author(s):  
Allison L. Bent ◽  
Donald V. Helmberger
Keyword(s):  
Fault Zone ◽  
Source Parameters ◽  
Travel Times ◽  
Considerable Uncertainty ◽  
San Jacinto Fault ◽  
San Jacinto Fault Zone ◽  
Moment Estimates ◽  
The Moment ◽  
Recent Earthquakes ◽  
Historic Earthquakes

Abstract The high level of seismic activity and the potential for large earthquakes in the San Jacinto fault zone, southern California, make it desirable to have accurate locations and source parameters for as many previous events as possible. Prior to the installation of a dense seismic network in this region, earthquakes were located using only a few stations with generally poor azimuthal coverage resulting in considerable uncertainty in the locations. We relocate and obtain moment estimates for historic (pre-WWSSN) earthquakes in the western Imperial Valley by comparing the waveforms and travel times with recent earthquakes in the region. All the events are in the ML 5.5 to 6.5 range. The historic earthquakes of interest occurred in 1937, 1942, and 1954. We use the 1968 Borrego Mountain, 1969 Coyote Mountain, and 1987 Elmore Ranch earthquakes as calibration events. We employ regional and teleseismic data from continuously operating stations, with Pasadena, DeBilt, Berkeley, Ottawa, and St. Louis recording most of the events. The waveforms imply that all the events are almost pure strike-slip events on vertical or near-vertical faults. Approximate values for the strikes were obtained and are within the range of observed strikes for well-studied earthquakes in this region. The earthquakes are relocated by comparing S-P and surface-wave - S travel times of historic events with the presumably well-located recent events. The relocations require only a small change in location for the 1954 event and a larger adjustment in the 1942 epicenter. It also appears that the 1969 earthquake may have been mislocated. The moment estimates are obtained by direct comparison of the maximum amplitudes. The moment estimates imply that the 1968 and not the 1942 earthquake is the largest to have occurred in the region this century. Previous magnitude estimates suggested the 1942 event was larger.

Sign in / Sign up

Export Citation Format

Share Document