5.7 Earthquake Strikes California-Mexico Border [Updated]
An earthquake with the preliminary magnitude of 5.9 (it was later downgraded to a 5.7) struck the California-Mexico border tonight. Originating 5 miles southeast of Ocotillo, CA at 9:26 p.m., it was felt widely across the Southland and is in the same region as the epicenter of the large Mexicali 7.2 quake on Easter Sunday. [Update: Tonight's event is considered an aftershock to the April earthquake, even though it is causing its own aftershocks, Bob Dollar of the USGS told the San Diego Union-Tribune. A seismologist at San Diego State University told the paper that "it is not uncommon to have an aftershock of this size" after the Easter quake.]
Tonight's quake, which was located about 65 miles east of the San Diego and Tijuana areas, had a depth of 6.8 km (4.2 miles), according to the USGS. It was followed by a series of smaller quakes, including a 3.9 shaker at 9:29 p.m.
[Update: More than 30 smaller quakes have occurred since the 5.9 struck. The largest as of 10:10 p.m. was a 4.5.
The Los Angeles Fire Department went into Earthquake Mode as a preventive measure, but said there were no immediate reports of damage within the city.]