An unusual swarm of hundreds of mostly small earthquakes has struck southern California over the last three days and shaken the nerves of residents, but scientists say the cluster is not a sign a larger temblor is imminent.
The earthquakes, the largest of which measured magnitude 5.5, began on Saturday evening.
They have been centred near the town of Brawley, close to the state's inland Salton Sea, said Jeanne Hardebeck of the U.S. Geological Survey.
