4.6 earthquake near Barstow sends seismic energy to northern San Diego County

A magnitude 4.6 earthquake occurred 14 miles north-northeast of Barstow at 7:03 p.m. on Friday, producing energy that was picked up by seismic stations in parts of northern San Diego County, according to the U.S. Geological Survey.

The temblor began 2.3 miles beneath the earth’s surface, making it a fairly shallow quake. The quake happened in the Mojave Desert, not far from the northern end of the Calico-Hidalgo fault system.

The USGS says the quake was picked up by seismometers at Santa Ysabel, Pala, Lake Henshaw, and Palomar Mountain. Light shaking was felt as far away as San Diego, Los Angeles and Las Vegas.

“I sure wish I could tell when a quake is going to be a foreshock,” Center for Science and Society seismologist Lucy Jones said on Twitter. “I spent many years looking at foreshocks to try to find something that made them different. Never found it ...

“We will know if it’s one of the 5% that become a foreshock if something bigger happens.”

Jones added that the quake, “Occurred on an unmapped thrust fault. Only Barstow seems to care.”

The Los Angeles Times reported that an average of 25 earthquakes with magnitudes between 4.0 and 5.0 occur per year in California and Nevada, according to a three-year data sample.