Project Abstract
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Assessments of seismic hazard in southern California are determined, in part, by fault geometry and slip rate estimates which can be used to constrain both potential rupture areas and earthquake recurrence intervals. An accurate accounting of fault slip rate estimates is essential for characterizing not only potential earthquake activity but also the partitioning of deformation between the Pacific and North American plates. A extant challenge in quantifying the total deformation budget in southern California is the extent to which deformation on a large number of small slip rate faults might accommodate a significant fraction of the relative plate motion. This is style of hypothesized deformation is sometimes referred to as “off fault” or “distributed”.
In 2007 we propose to apply a newly developed statistical model of fault slip rates to quantify the extent of “distributed deformation” in southern California. These models will provide new constrains on the partitioning slip between different parts of the fault system and address a fundamental question in seismic hazard analysis. In particular whether or not “off-fault” or “distributed deformation” contributes significantly to earthquake hazard from a moment balance perspective. This analysis is a necessary step along the way to rigorously computing the rates and spatial pattern of moment accumulation and release across the southern California fault system. The proposed work will make use of existing SCEC derived research products, in particular the geodetically constrained fault slip rate models (e.g., Meade and Hager, 2005) and compilations of geologically constrained fault slip rates (e.g., Petersen and Wesnousky, 1994). |
