San Andreas Fault
The San Andreas Fault Observatory at Depth (SAFOD) consists of a main borehole that cuts across the active San Andreas Fault at a depth of approximately 3 km and a pilot hole about 2 km southwest of San Andreas Fault. Data from the instruments installed in the holes, which consist of geophone sensors, data acquisition systems, and GPS clocks, as well as samples collected during drilling, will help to better understand the processes that control the behavior of the San Andreas Fault.