New Look at the San Andreas Fault

Seismologists are particularly interested in the stretch of the San Andreas Fault shown in the new composite image at right. Just north of this region in 1857, one of the largest earthquakes ever recorded in U.S. history erupted, measuring an estimated 8.0 in magnitude on the Richter scale. The quake shook buildings in Los Angeles, rattled Las Vegas and ruptured the ground's surface along 350 kilometers of the fault, which itself runs for 1,200 kilometers. To better visualize the region, scientists married an enhanced, true-color Landsat satellite image with data from NASA's Shuttle Radar Topography Mission (SRTM), doubling the elevation of prominant features for better perspective. The result looks southeast towards the snowcapped peak of Mt. Pios. The fault is the linear feature running along the base of mountains in the Temblor Range near Bakersfield. Parts of the agriculturally rich San Joaquin Valley appear to its left, and the Carrizo Plain is on its right. The three-dimensional measurements of the earth's surface came from the space shuttle Endeavour's flight last February. During its 10 days in orbit, SRTM gathered similar data for 80 percent of the earth's landmass, generating the most extensive high-resolution collection of information about our planet's topography yet.