Earthquakes are not uncommon in parts of California along the San Andreas fault. Major quakes in 1994 in Northridge and 2014 in Napa have given residents reason to take earthquake threats seriously. On September 30th, the California Office of Emergency Services issued a warning to southern California residents. The warning was prompted by information from the US Geological Survey that recorded more than 140 seismic events near Bombay Beach along the Salton Sea. The sea sits directly on the San Andreas fault and the events that triggered the warning ranged from 1.4 to 4.3 on the Richter scale. While quakes are to be expected in this region, the swarm of events all in the same area in such a short time period was out of the norm.
On October 4th, the warning was cancelled, after more information showed that the danger had passed and seismic activity in the area had slowed. While the warning was issued based on sound information, it did cause a bit of anxiety for some California residents. Even with the increased amount of small quakes, the odds of a larger earthquake happening were only increased by one half of one percent.