HR: 16:15h
AN: S34A-02    [Abstracts]
TI: Seismic Hazard Model for Chile
AU: * Williams, C R
EM: Chesley.Williams@rms.com
AF: Risk Management Solutions Inc, 7015 Gateway Boulevard, Newark, CA 94560 United States
AU: Molas, G L
EM: Gilbert.Molas@rms.com
AF: Risk Management Solutions Inc, 7015 Gateway Boulevard, Newark, CA 94560 United States
AU: Hall, L S
EM: Lisa.Hall@rms.com
AF: Risk Management Solutions Inc, 7015 Gateway Boulevard, Newark, CA 94560 United States
AU: Windeler, D S
EM: Don.Windeler@rms.com
AF: Risk Management Solutions Inc, 7015 Gateway Boulevard, Newark, CA 94560 United States
AB: A seismic hazard model for Chile has been created as part of the development of a seismic risk model for the region. The methodology used to implement the model follows that used by the U.S. Geological Survey in the 2002 National Seismic Hazard Maps. The seismic sources are divided into shallow crustal (active faults and background seismicity), interface and intraslab. The Nazca subduction zone has been segmented based on historical seismicity. The interface event set includes multisegment cascading events. The fault and subduction zones sources are modeled based on slip rates using characteristic recurrence; where applicable, time dependent assumptions have been included. The background and intraslab event rates are defined based on observed seismicity and modeled using a Gutenberg-Richter recurrence model. The ground motion model differentiates between seismic source types. Regional scale geotechnical data for Chile has been incorporated via the 1:1m scale national geologic map by SERNAGEOMIN, 2002. Hazard curves have been created for the major cities in Chile, including Santiago, Valparaiso, Concepcion and Antofagasta. The hazard for these cities has been deaggregated to show the contribution to the hazard by source type, magnitude and distance. This analysis shows that the seismic hazard in the coastal cities is driven by the subduction zone sources, while the inland cities such as Santiago are also impacted by the shallow crustal and intraslab seismicity. This model has also been utilized to develop a suite of seismic hazard maps for PGA at various return periods (475, 1000 and 2500 years).
DE: 7223 Seismic hazard assessment and prediction
SC: Seismology [S]
MN: 2004 AGU Fall Meeting