The United States Geological Survey recorded a Magnitude 4.6 Earthquake at a depth of 14.7 km in northern Baja California State, Mexico, slightly before 9.30 pm local time on Thursday 19 December 2013 (slightly before 5.30 am on Friday 20 December, GMT). There are no reports of any damage or casualties arising from this event, though it was felt across much of northern Baja California as well as southern California and southwest Arizona in the US.
The approximate location of the 19 December 2013 Baja California Earthquake. Google Maps.
The boundary between the Pacific and North American Plates runs beneath the Gulf of California, 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 and in the surrounding area.
See also Magnitude 6.5 Earthquake beneath the Gulf of California, Magnitude 4.6 Earthquake in Chihuahua State, Mexico, Magnitude 2.8 Earthquake in Baja California, Magnitude 5.3 Earthquake in Chihuahua State, Mexico and Magnitude 4.1 Earthquake in northeast Baja California.
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