Slide Words: Earthscope
Slide Image: The illustration shows the Earthscope observatory, installed four kilometers beneath the surface of California below the San Andreas Fault Zone. The image shows a 4 kilometer-deep drilled hole on the left side of San Andreas Fault Zone. The hole curves under the Fault Zone and shows sensors after 2.5 kilometers to 4 kilometers. The sensors search for signals that could alert us to a major earthquake.
Credit: Trent Schindler, National Science Foundation