A Magnitude 4.6 Earthquake occurred at a depth of 7.4 km roughly 2 km off the coast of Isla Vista, California, slightly before 7.40 am local time (slightly before 4.40 pm GMT) on Wednesday 29 May 2013, according to the United States Geological Survey. This is a moderately large Earthquake in an area with a fairly high population, though California is used to and prepared for such events. The USGS estimates there is a 26% chance of a quake of this size in this area causing at least one fatality, though no damage or injuries have been reported from this event. The quake was felt as far away as Los Angeles, 150 km to the east.
The location of the 29 May 2013 Earthquake. Google Maps.
California is extremely prone to Earthquakes due to the presence of the San Andreas Fault, a tectonic plate margin that effectively bisects the state. The west of California, including Isla Vista, Santa Barbara and Los Angeles, is located on the Pacific Plate, and is moving to the northwest. The east of California, including Fresno and Bakersfield is on the North American Plate, and is moving to the southeast. The plates do not move smoothly past one-another, but constantly stick together then break apart as the pressure builds up. This has led to a network of smaller faults that criss-cross the state, so that Earthquakes can effectively occur anywhere.
Movement on the San Andreas Fault. David Lynch/SanAndreasFault.org.
Witness accounts of Earthquakes can help geologists to understand these events and the underlying structures that cause them. If you felt this quake (or if you were in the area but did not, which is also useful information) then you can report it to the United States Geological Survey here.
See also Northeast California shaken by Magnitude 5.7 Earthquake, Los Angeles shaken by Earthquake, Magnitude 6.3 Earthquake off the coast of Baja California, Central California shaken by Earthquake and Earthquake swarm strikes southern California.
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