4.7 Earthquake in Anza Shows Earthquake Early Warning's Potential

Courtesy of USGS

On March 11, 2013, a magnitude 4.7 earthquake struck about 13 miles ESE of Anza, CA, which is west of the Salton Sea by about 20 miles. The earthquake was located on the San Jacinto Fault, which is very active and is capable of earthquakes around the magnitude of 7.0.

The earthquake was immediately detected, and provided a warning to the test users of the Shakealert system, giving about 30 seconds warning to scientists in Pasadena. The earthquake was originally estimated to be 5.2 in magnitude but was later downgraded to 4.7. Although the system slightly overestimated the magnitude, the quake shows the potential of the warning system to protect vulnerable infrastructure.

If you felt this earthquake in your location and would like to contribute your experience to USGS, visit:
http://earthquake.usgs.gov/earthquakes/eventpage/ci15296281#dyfi_form