Southern San Andreas Fault Evaluation (SoSAFE)

The newly formed SCEC Southern San Andreas Fault Evaluation (SoSAFE) Project will increase our knowledge of slip rates, paleo-event chronology, and slip distributions of past earthquakes, for the past two thousand years on the southern San Andreas fault system. From Parkfield to Bombay Beach, and including the San Jacinto fault, the objective is to obtain new data to clarify and refine relative hazard assessments for each potential source of a future 'Big One.'

The first year of SoSAFE is expected to be funded at $240K by USGS, but these funds are still pending. If funded, targeted research by each of several selected self-organized multiinvestigator teams will be supported to rapidly advance SCEC research towards meeting objective A1. We encourage investigator teams to propose jointly in response to the RFP, despite the fact that funds are still pending at this time. Each team will address one significant portion of the fault system, and all teams will agree to collaboratively review one another’s progress.

Other SCEC objectives will also be advanced through the research funded by SoSAFE, such as A2, A10, and B1. For example, interaction between SoSAFE and the scenario rupture modeling activity will occur as we discuss whether or not additional radiocarbon dating could be used to eliminate the scenario of a “wall-to-wall” rupture (from Parkfield to Bombay Beach). SoSAFE will also work to constrain scenario models by providing the best possible measurements of actual slip distributions from past earthquakes on these same fault segments as input, thereby enabling a more realistic level of scenario modeling. Use of novel methods for estimating slip rates from geodetic data would also potentially be supported within the first year of funding, although it is expected that much support will go towards improved dating (e.g., radiocarbon and OSL) of earthquakes so that event correlations can be further refined.

A SCEC SoSAFE Project workshop on January 8-9, 2007 will commemorate the 1857 Fort Tejon earthquake by establishing our first year SoSAFE plan. Each proposing team will make a coordinated cluster of presentations at the upcoming workshop to describe their planned approach to making progress on understanding the specific section of the fault system where they propose to work. We will also discuss common longer-term research interests and engage in facilitating future collaborations in the broader context of a decade-long series of interdisciplinary, integrated and complementary studies on the southern San Andreas fault system.