A probabilistic seismic hazard analysis (PSHA) will be conducted to assess the levels of vibratory ground motions expected during various time periods. The results will be used to update current seismic hazard maps that have been used in the Santa Barbara Channel area since the 1960's, in the review of seismic design criteria and seismic performance of offshore structures. This is a 2 year, 3 phase project. The first phase of the study will collect data from the USGS, MMS, relevant experts, and oil companies to identify all available seismic design criteria for offshore platforms. Data collection will focus on data collected in the last few years including proprietary data from industry. Phase 2 will be a 2 day workshop on the state of the art of seismic hazard criteria for offshore platforms on the west coast continental shelf. Phase 3 will be a PSHA analysis of the Phase 1 and 2 studies and a review by a peer review panel. The effort will be conducted as a joint project with the California State Lands Commission.
Two basic models were developed: thick skinned (Model 1) and thin skinned (Model 2). Each model was characterized based on four factors geometries; probability distribution for fault slip rates; probability distribution of characteristic moment magnitudes (Mw); and earthquake recurrence rate distributions.