San Andreas Fault Observatory at Depth
EarthScope's San Andreas Fault Observatory at Depth (SAFOD) is a 3-kilometer deep hole drilled directly into the San Andreas Fault near Parkfield, California. SAFOD is providing the first opportunity to directly observe the conditions under which earthquakes occur in an active fault.
For the first time, rocks and fluids have been collected from deep within an active fault. Scientists were surprised to find a pretty common mineral deep in the San Andreas fault: Talc. If you have used baby powder, you have used talc. The slippery talc contributes to the slipperiness of this section of the San Andrea fault, leading to more frequent and smaller earthquake on this section of the fault.