The United States Geological Survey recorded a Magnitude 3.1 Earthquake at a depth of 4.5 km to the north of the Gulf of California in Baja California State, Mexico, slightly after 2.05 pm local time (slightly after 9.05 pm GMT) on Thursday 5 September 2013. This is not a large quake, and is unlikely to have caused any damage or casualties, though it was probably felt locally.
The approximate location of the 5 September 2015 Gulf of California Earthquake. Google Maps.
The Gulf of California lies on the boundary between the Pacific and North American Plates, with Beja California lying on the Pacific Plate and the Mexican mainland on the North American. The Pacific Plate is moving northwest with regard to the North American Plate, while the North American Plate is moving southeast relative to the Pacific Plate. This creates a transform plate margin along the center of the Gulf of California, as the two plates slide past one-another, a margin that continues northward under California as the San Andreas Fault. The plates do not move past one-another smoothly, but continuously stick together then break apart as the pressure builds up, leading to regular Earthquakes beneath the Gulf of California.
There is also a degree of spreading starting to occur on this plate margin, to the south it becomes a spreading plate margin, the East Pacific Rise, generating new seafloor on the Rivera, Cocos and Nazca Plates, and feeding the subduction zones off the coasts of Central and South America.
See also Magnitude 3.2 Earthquake in southern California, Los Angeles shaken by Earthquake, Magnitude 6.3 Earthquake off the coast of Baja California, Earthquake in the Gulf of California and Earthquake swarm strikes southern California.
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