More than 100 aftershocks have now rocked the southern California town of Ridgecrest in the Mojave Desert, with the ground shaking every few minutes.
Yesterday's 6.4 magnitude earthquake was the strongest to hit the area in 20 years, and a state of emergency has been declared for Kern County.
Seismologists at the California Institute of Technology say residents should be prepared for aftershocks to continue for a few more days, with a one in 20 chance of an aftershock bigger than the actual 6.4 quake.