Descr: We shall deploy 100 three-component REFTEKS in dense seismic arrays across and along the SAF at Parkfield to record fault-zone trapped waves generated by near-surface explosions and micro- earthquakes for a month in 2002 fall. The data will be used for characterization of internal structure and physical properties of the SAF in 4-D. This research project is a SAFOD Pre-EarthScope activity. We shall work with other research teams (John Hole of VT, Cliff Thurber of UW, and Michael Rymer and Rufus Catchings of USGS et al.) in the field under the coordination of SAFOD program PIs.