San Andreas Drillers Find a Strangely Weak Fault

摘要

Drillers have punched kilometers down through the San Andreas fault for the first time. A first glance at this "natural earthquake machine" reveals that the fault is relatively weak but not what weakened it, researchers reported at the meeting. In their quest to understand how quakes get started and why almost all fizzle out, investigators will drill straight through the heart of San Andreas quakes as they build the San Andreas Fault Observatory at Depth (SAFOD).