SCEC Award Number 07126 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title Assessing the Magnitude of Off-Fault Damage along the Southeastern San Jacinto Fault Zone: Is It 20-30% of the Slip?
Name Organization
Susanne Janecke Utah State University
Other Participants
SCEC Priorities A7, A1, A2 SCEC Groups Geology, FARM, SoSAFE
Report Due Date N/A Date Report Submitted N/A
Project Abstract
The San Jacinto fault zone accommodated up to half the plate motion in southern California yet estimates of total displacement, and the lifetime slip rate may underestimate the actual strain accumulation if a large fraction of slip is taken up by folded crystalline rocks and basin fill adjacent to the fault zone.
This proposal will test our hypothesis that there is up to 20-30% ADDITIONAL
strain in a damage zone parallel to the main strands of the Clark and Coyote Creek fault. We have identified two thin, distinctive zone of marbles within the Eastern Peninsular Ranges mylonite zone that are likely to correlate across the faults and appears to be folded, faulted and rotated in a 1-2 km wide damage zones adjacent to both faults. If our hypothesis is correct, the San Jacinto fault zone may have slipped at a lifetime slip rate approaching 23 mm/yr. This value exceeds even the highest estimates from paleoseismic studies.