Time-independent and Time-dependent Seismic Hazard Assessment for the State of California: Uniform California Earthquake Rupture Forecast Model 1.0

Ground-shaking hazard maps based on sound earth-science research are effective tools for mitigating damage from future earthquakes. Assuming that future earthquakes will occur on active faults or near previous events and that the ground shaking from these events will fall within the range of globally recorded ground motions leads to probabilistic hazard maps that predict ground-shaking potential across a region. Developing hazard and risk maps requires technical interactions between earth scientists and engineers to estimate the rate of potential earthquakes across a region, quantify likely ground-shaking levels at a site, and understand how buildings respond to strong ground shaking. For the past 25 years the U.S. Geological Survey (USGS) and California Geological Survey (CGS) have cooperated with government officials and professional organizations to incorporate hazard maps and other hazard products in public and corporate documents such as building codes, insurance rate structures, and earthquake risk mitigation plans (Algermissen and Perkins 1982; Frankel et al. 1996, 2002; Petersen et al. 1996). Because these hazard products are used in making public-policy decisions, it is essential that the official USGS-CGS hazard models reflect the “best available science.” This qualification is also required by the statute that regulates the California Earthquake Authority, which provides most earthquake insurance in the state. To adequately represent the “best available science,” hazard maps need to be updated regularly to keep pace with new scientific advancements. The methodologies, computer codes, and input data used in developing these products need to be openly available for review and analysis. Input parameters and codes for current hazard maps may be obtained at http://earthquake.usgs.gov/hazmaps and http://www.consrv.ca.gov/cgs. At these Web sites a user may access documentation that describes methodologies and parameters, a relational database and tables that contain explanations of how the fault parameters and uncertainties were chosen, interactive …

[1]  James H. Dieterich,et al.  Probabilities of large earthquakes occurring in California on the San Andreas Fault , 1988 .

[2]  Mark D. Petersen,et al.  A Time-Dependent Probabilistic Seismic-Hazard Model for California , 2000 .

[3]  K. Campbell,et al.  Updated Near-Source Ground-Motion (Attenuation) Relations for the Horizontal and Vertical Components of Peak Ground Acceleration and Acceleration Response Spectra , 2003 .

[4]  Mark D. Petersen,et al.  Comparison of the Historical Record of Earthquake Hazard with Seismic- Hazard Models for New Zealand and the Continental United States , 2006 .

[5]  D. P. Schwartz,et al.  Fault behavior and characteristic earthquakes: Examples from the Wasatch and San Andreas Fault Zones , 1984 .

[6]  William A. Bryant,et al.  Probabilistic seismic hazard assessment for the state of California , 1996 .

[7]  L. Knopoff,et al.  Is the sequence of earthquakes in Southern California, with aftershocks removed, Poissonian? , 1974, Bulletin of the Seismological Society of America.

[8]  A. Frankel.  Mapping Seismic Hazard in the Central and Eastern United States , 1995 .

[9]  Gail M. Atkinson,et al.  Empirical Ground-Motion Relations for Subduction-Zone Earthquakes and Their Application to Cascadia and Other Regions , 2003 .

[10]  R. Youngs,et al.  Attenuation Relationships for Shallow Crustal Earthquakes Based on California Strong Motion Data , 1997 .

[11]  David M. Boore,et al.  SEA99: A Revised Ground-Motion Prediction Relation for Use in Extensional Tectonic Regimes , 2005 .

[12]  David D. Jackson,et al.  Seismic hazards in southern California: probable earthquakes, 1994 to 2024 , 1996 .

[13]  Mark D. Petersen,et al.  Simulations of Seismic Hazard for the Pacific Northwest of the United States from Earthquakes Associated with the Cascadia Subduction Zone , 2002 .

[14]  D. Perkins,et al.  National Seismic-Hazard Maps: Documentation June 1996 , 1996 .

[15]  N. Abrahamson,et al.  Empirical Response Spectral Attenuation Relations for Shallow Crustal Earthquakes , 1997 .

[16]  B. Gutenberg,et al.  Frequency of Earthquakes in California , 1944, Nature.

[17]  W. B. Joyner,et al.  Equations for Estimating Horizontal Response Spectra and Peak Acceleration from Western North American Earthquakes: A Summary of Recent Work , 1997 .

[18]  S. T. Algermissen,et al.  A probabilistic estimate of maximum acceleration in rock in the contiguous United States , 1976 .

[19]  H. Kanamori,et al.  A seismotectonic analysis of the Anza Seismic Gap, San Jacinto Fault Zone, southern California , 1984 .

[20]  D. P. Schwartz,et al.  Probabilities of Large Earthquakes in the San Francisco Bay Region, California , 1990 .

[21]  Mark D. Petersen,et al.  Discrepancy between Earthquake Rates Implied by Historic Earthquakes and a Consensus Geologic Source Model for California , 2000 .

[22]  W. Silva,et al.  Strong Ground Motion Attenuation Relationships for Subduction Zone Earthquakes , 1997 .

[23]  S. Harmsen,et al.  Documentation for the 2002 update of the national seismic hazard maps , 2002 .