An M3.1 earthquake rattled Southern California last night at 11:07pm PDT, approximately 15 kilometers (9 miles) east of Mecca, CA and emanating from a depth measured at 9.4 kilometers (5.8 miles).
As the quake was small enough to produce only light shaking in the region, no damage was caused and according to the USGS website’s “Did You Feel It?” feature, only one report was submitted.
Assigned a II on the Modified Mercalli Intensity Scale, the shaking produced by the quake would likely have only been detectable by a small number of people located on the upper floors of buildings and would probably not be immediately recognized as an earthquake.
Tectonic Setting of Last Night’s Quake
The earthquake last night, like many others in California, can be attributed to movement along the San Andreas Fault. This infamous geologic feature stretches along the western flank of the state and forms the boundary between the northwest moving Pacific plate and the southeast moving North American plate.
Known as a transform boundary, this type of fault produces lateral movement of the crust on either side as plates grind past one another. At a convergent boundary, one plate will override another, and at a divergent plate boundary, plates are pulling apart from one another.
Mecca California’s Seismic Past
With its long history of geologic activity, this region is no stranger to earthquakes. Just a few weeks ago on June 14, a M2.8 was detected in the Mecca area, though at a much shallower depth of 0.1 kilometers.
The largest earthquake to ever occur in the area was the M7.4 Owens Valley event in 1872. The small town of Lone Pine was hardest hit, with 52 of 59 houses destroyed and 27 residents were killed. In certain areas along the fault, the ground had been horizontally displaced as much as seven meters. The quake was felt across most of California and into Nevada as well.
San Andreas Fault’s Seismic Future
As the two large Pacific and North American plates continue their slow movement around the planet,seismic activity along the San Andreas will also occur. Because it is impossible to predict or prevent earthquakes, being educated about potential hazards and being prepared for a possible disaster is key to living in an earthquake-prone region.