Should Southern California Be Shaken by the Recent Quake Warning?

Last week, a swarm of 200 small earthquakes rumbled under the Salton Sea, a saline lake in Southern California. Although only three of the quakes measured above 4.0 on the Richter scale, seismologists worry that these temblors may portend a more dramatic earthquake to come.

According to research published in Nature by geologist Colin Amos of Western Washington University, the vast amount of recent groundwater extraction in the agriculturally productive San Joaquin Valley could actually be contributing to earthquakes along the San Andreas fault. The reason: Water is heavy, and when it's removed in great volumes, tectonic plates deep beneath the aquifer can move more freely.