Spatial seismicity rates and maximum magnitudes for background earthquakes

Open-File Report 2007-1437- J
Prepared in cooperation with the California Geological Survey and the Southern California Earthquake Center
By: , and 



The background seismicity model is included to account for M 5.0 - 6.5 earthquakes on faults and for random M 5.0 ? 7.0 earthquakes that do not occur on faults included in the model (as in earlier models of Frankel et al., 1996, 2002 and Petersen et al., 1996). We include four different classes of earthquake sources in the California background seismicity model: (1) gridded (smoothed) seismicity, (2) regional background zones, (3) special fault zone models, and (4) shear zones (also referred to as C zones). The gridded (smoothed) seismicity model, the regional background zone model, and the special fault zones use a declustered earthquake catalog for calculation of earthquake rates. Earthquake rates in shear zones are estimated from the geodetically determined rate of deformation across an area of high strain rate. We use a truncated exponential (Gutenberg-Richter, 1944) magnitude-frequency distribution to account for earthquakes in the background models.

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Spatial seismicity rates and maximum magnitudes for background earthquakes
Series title Open-File Report
Series number 2007-1437
Chapter J
DOI 10.3133/ofr20071437J
Edition Version 1.0
Year Published 2008
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Earthquake Hazards Program, Earthquake Science Center, Geologic Hazards Science Center
Description iii, 8 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Appendix J in The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2)
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