As swarms of smaller earthquakes are taking place every day.
"California may be about to be hit by a massive magnitude 7 earthquake after geologists discovered a succession of smaller tremors under a lake near the San Andreas fault."
http://www.independent.co.uk/news/world/americas/massive-7-magnitude-earthquake-southern-california-oes-usgs-experts-swarm-salton-sea-san-andreas-a7340936.html