SAFOD as part of Earth Scope has drilled and instrumented an inclined borehole across the San Andreas Fault Zone to a depth of 3.2 km, targeting a repeating microearthquake source. 

The array includes: Fiber-optic cable head, DS325 locking arm, Pinnacle high-temperature tiltmeter, GERI DS250/DS150 adaptor, GERI DS150 65m interconnect, GERI DS150 seismometer, GERI DS150 65m interconnect, GERI DS150 seismometer, GERI DS150 3m interconnect and weight bar.

8 ½” borehole, 125 °C static temperature, max. depth 3998 m, longest operation: 2 months

Sept. 2006: the array had to be recovered due to cable transmission failures and gas influx in the instrument packages. Waiting on NSF approval for a new installation since.