Publications
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Paleoseismic Investigations of the Walnut Site on the San Jacinto Fault
The Walnut paleoseismic site is located along the northern San Jacinto fault about 3 km southeast of the San Bernardino, California city center (Figures 1, 2). More than 340 meters of trenches were excavated across the fault zone at this site as part of an Alquist-Priolo fault study (Figure 3). We photographed and logged the SE wall and most of the NE wall of trench 1, both walls of trenches 2 and
Authors
T. E. Fumal, K.J. Kendrick
Empirical estimation of regional time variation in seismicity rates
No abstract available.
Authors
Karen R. Felzer
A-priori rupture models for Northern California Type-A faults
This appendix describes how a-priori rupture models were developed for the northern California Type-A faults. As described in the main body of this report, and in Appendix G, “a-priori” models represent an initial estimate of the rate of single and multi-segment surface ruptures on each fault. Whether or not a given model is moment balanced (i.e., satisfies section slip-rate data) depends on assum
Authors
Chris J. Wills, Ray J. Weldon, Edward H. Field
Conditional, time-dependent probabilities for segmented Type-A faults in the WGCEP UCERF 2
This appendix presents elastic-rebound-theory (ERT) motivated time-dependent probabilities, conditioned on the date of last earthquake, for the segmented type-A fault models of the 2007 Working Group on California Earthquake Probabilities (WGCEP). These probabilities are included as one option in the WGCEP?s Uniform California Earthquake Rupture Forecast 2 (UCERF 2), with the other options being t
Authors
Edward H. Field, Vipin Gupta
Cascadia Subduction Zone
The geometry and recurrence times of large earthquakes associated with the Cascadia Subduction Zone (CSZ) were discussed and debated at a March 28-29, 2006 Pacific Northwest workshop for the USGS National Seismic Hazard Maps.
The CSZ is modeled from Cape Mendocino in California to Vancouver Island in British Columbia. We include the same geometry and weighting scheme as was used in the 2002 mod
Authors
Arthur D. Frankel, Mark D. Petersen
Spatial seismicity rates and maximum magnitudes for background earthquakes
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,
Authors
Mark D. Petersen, Charles S. Mueller, Arthur D. Frankel, Yuehua Zeng
Calculating California seismicity rates
Empirically the rate of earthquakes = magnitude M is well fit by the Gutenberg-Richter relationship, logN=a-bM (1) where N is the number of earthquakes = M over a given time period, a is the number of M = 0 earthquakes over the same period, and b is a parameter that determines the ratio of larger to smaller earthquakes (Ishimoto and Iida 1939; Gutenberg and Richter 1944). Thus to characterize the
Authors
Karen R. Felzer
WGCEP historical California earthquake catalog
This appendix provides an earthquake catalog for California and the surrounding area. Our goal is to provide a listing for all known M > 5.5 earthquakes that occurred from 1850-1932 and all known M > 4.0 earthquakes that occurred from 1932-2006 within the region of 31.0 to 43.0 degrees North and -126.0 to -114.0 degrees West. Some pre-1932 earthquakes 4 < M < 5.5 are also listed. The completeness
Authors
Karen R. Felzer, Tianqing Cao
Summary of geologic data and development of A Priori Rupture Models for the Elsinore, San Jacinto, and Garlock faults
This appendix to the WGCEP Earthquake Rate Model 2 summarizes geologic data and documents the development of the rupture models for the Elsinore, San Jacinto, and Garlock faults. For the summary of available geologic data, the documentation is organized by fault and fault segment and includes a summary of slip rates, event timing and recurrence, slip-per-event, and historical seismicity for each s
Authors
Timothy E. Dawson, Tom K. Rockwell, Ray J. Weldon, Chris J. Wills
Development of final a-fault rupture models for WGCEP/ NSHMP Earthquake Rate Model 2
This appendix discusses how we compute the magnitude and rate of earthquake ruptures for the seven Type-A faults (Elsinore, Garlock, San Jacinto, S. San Andreas, N. San Andreas, Hayward-Rodgers Creek, and Calaveras) in the WGCEP/NSHMP Earthquake Rate Model 2 (referred to as ERM 2. hereafter). By definition, Type-A faults are those that have relatively abundant paleoseismic information (e.g., mean
Authors
Edward H. Field, Ray J. Weldon, Thomas Parsons, Chris J. Wills, Timothy E. Dawson, Ross S. Stein, Mark D. Petersen
Overview of the Southern San Andreas Fault Model
This appendix summarizes the data and methodology used to generate the source model for the southern San Andreas fault. It is organized into three sections, 1) a section by section review of the geological data in the format of past Working Groups, 2) an overview of the rupture model, and 3) a manuscript by Biasi and Weldon (in review Bulletin of the Seismological Society of America) that describe
Authors
Ray J. Weldon, Glenn P. Biasi, Chris J. Wills, Timothy E. Dawson
Earthquake Rate Model 2 of the 2007 working group for California earthquake probabilities, magnitude-area relationships
The Working Group for California Earthquake Probabilities must transform fault lengths and their slip rates into earthquake moment-magnitudes. First, the down-dip coseismic fault dimension, W, must be inferred. We have chosen the Nazareth and Hauksson (2004) method, which uses the depth above which 99% of the background seismicity occurs to assign W. The product of the observed or inferred fault l
Authors
Ross S. Stein