LEAP; local earthquake analysis programs on VAX-VMS for Southern California Seismic Network data

1992 ◽  
Author(s):  
L.A. Wald ◽  
L.M. Jones
Keyword(s):  
Southern California ◽  
Seismic Network ◽  
Network Data ◽  
Local Earthquake

scholarly journals Global positioning system resurvey of Southern California Seismic Network stations

1995 ◽  
Vol 85 (1) ◽  
pp. 361-374
Author(s):  
Jennifer S. Haase ◽  
Egill Hauksson ◽  
Hiroo Kanamori ◽  
Jim Mori
Keyword(s):  
Global Positioning System ◽  
Southern California ◽  
Seismic Station ◽  
Seismic Network ◽  
Positioning System ◽  
Dual Frequency ◽  
Time Data ◽  
Phase Measurements ◽  
Station Coordinates ◽  
Global Positioning

Abstract Systematic errors in travel-time data from local earthquakes can sometimes be traced to inaccuracies in the published seismic station coordinates. This prompted a resurvey of the stations of the Caltech/USGS Southern California Seismic Network (SCSN) using the Global Positioning System (GPS). We surveyed 241 stations of the SCSN using Trimble and Ashtech dual-frequency GPS receivers and calculated positions accurate to 3 m using differential positioning from carrier phase measurements. Twelve percent of the stations that were surveyed were found to be mislocated by more than 500 m. Stations of the TERRAscope and USC networks were also surveyed, as well as a network of portable seismic stations deployed shortly after the 1992 Joshua Tree and Landers earthquakes. The new coordinates and the offsets from the old coordinates are given below. The new coordinates are being used in SCSN locations as of 1 January 1994.

The 1997 Southern California Seismic Network Bulletin

1998 ◽  
Vol 69 (6) ◽  
pp. 532-549 ◽  
Author(s):  
L. A. Wald ◽  
L. M. Jones ◽  
S. Schwarz ◽  
L. K. Hutton
Keyword(s):  
Southern California ◽  
Seismic Network

Methods for Amplitude Calibration and Orientation Discrepancy Measurement: Comparing Co‐Located Sensors of Different Types in the Southern California Seismic Network

2019 ◽  
Vol 109 (4) ◽  
pp. 1563-1570 ◽  
Author(s):  
Zefeng Li ◽  
Egill Hauksson ◽  
Jennifer Andrews
Keyword(s):  
Southern California ◽  
Dynamic Range ◽  
Strong Motion ◽  
Seismic Network ◽  
Motion Sensors ◽  
Vertical Orientation ◽  
Horizontal Orientation ◽  
California Institute Of Technology ◽  
Short Period ◽  
Institute Of Technology

Abstract Modern seismic networks commonly equip a station with multiple sensors, to extend the frequency band and the dynamic range of data recorded at the station. In addition, in our recent study we showed that comparison of data from co‐located seismometers and accelerometers is useful for detecting instrument malfunctions and monitoring data quality. In this study, we extend comparison of data from different co‐located sensors to two other applications: (1) amplitude calibration for data from vertical short‐period sensors with strong‐motion sensors as baseline and (2) measurement of orientation discrepancy between strong‐motion and broadband sensors. We perform systematic analyses of data recorded by the California Institute of Technology/U.S. Geological Survey Southern California Seismic Network. In the first application, we compare the amplitude of data from vertical short‐period sensors to that of data from co‐located strong‐motion sensors and measure the amplitude calibration factors for 93 short‐period sensors. Among them, 49 stations are measured at ∼1.0, 42 measured at ∼0.6, as well as two outlying stations: GFF at 0.3 and CHI at 1.3. These values are found to be related to the sensors’ sensitivity values. In the second application, we measure orientation discrepancy between 222 co‐located broadband and strong‐motion sensors. All the vertical orientation differences are found to be within 5°. However, the horizontal orientation differences of 22 stations are greater than 6°, among which four stations have reverse rotation or 180° from the expected orientation. These measurements have been communicated to network operators and fixes are being applied. This study, together with our previously developed data monitoring framework, demonstrates that comparison of different co‐located sensors is a simple and effective tool for a broad range of seismic data assessment and instrument calibration.

Education and Outreach Based on Data from the Anza Seismic Network in Southern California

2003 ◽  
Vol 74 (5) ◽  
pp. 522-528 ◽  
Author(s):  
D. Kilb ◽  
R. L. Newman ◽  
F. L. Vernon ◽  
J. A. Eakins ◽  
L. Ziegler ◽  
...  
Keyword(s):  
Southern California ◽  
Seismic Network ◽  
Education And Outreach

The 1998 Southern California Seismic Network Bulletin

1999 ◽  
Vol 70 (4) ◽  
pp. 404-416
Author(s):  
L. A. Wald ◽  
D. J. Wald
Keyword(s):  
Southern California ◽  
Seismic Network
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