Characterization of the San Andreas Fault at Parkfield by Fault-Zone Trapped Waves: A SAFOD Pre-EarthScope Activity

University Of Southern California, Los Angeles CA

Investigators

Abstract

0207214 Li EarthScope is a major earth science research initiative that will integrate scientific information derived from seismology (US Array), geodesy (Plate boundary Observatory), subsurface sampling and measurement (SAFOD), remote sensing (InSAR), and complementary geology and geophysics to understand continental scale plate deformation and evolution. Funding for the EarthScope initiative is currently being discussed in Congress as part of NSF's FY 2003 budget. The Division of Earth Sciences has made FY 2002 funds available for projects that qualify as pre-EarthScope activity, i.e. activities that will facilitate or enable the construction, fabrication, installation or operation of EarthScope once it is funded under the MREFC (Major Research Equipment Facilities and Construction) account. Such activities include meetings and workshops, prototype development, site selection or characterization. This award will provide funds to support the deployment of dense linear seismic arrays across and along the San Andreas fault (SAF) near the SAFOD drilling site at Parkfield, CA to record fault-zone trapped waves generated by explosions and microearthquakes. Since the features of fault-zone trapped waves strongly depend on the fault geometry and physical properties, these waves can be used to determine spatial and temporal variation in fault properties with high precision. This experiment will be a supplement to other seismic experiments at Parkfield scheduled in the Fall of 2002. ***