Southern Californians are used to earthquakes the way those in New England are used to blizzards, but they can be alarming even when they don’t cause serious damage.
That’s the case for a tremor that was centered in Pasadena, near Los Angeles, on August 12. At 20 minutes past 12, the U.S. Geological Survey said a quake measuring 4.4 on the Richter Scale gave people a “pretty good jolt.” That’s how seismologist Susan Hough described it, adding that it was a “decent shake.”
A quake of 4.4 might break windows or cause small objects to tip over.
Most quakes are followed by smaller aftershocks, and this one was no different. About two minutes after the initial shake, a 2.1 aftershock could be felt as far away as San Diego and Bakersfield, each more than 100 miles from Pasadena. The epicenter of the quake was apparently in the Los Angeles neighborhood of El Sereno.
Though California sits on the famous San Andreas fault, that’s not the only rift between large pieces of land in the area. Earthquakes happen when two large pieces of earth, or plates, “slip” along a fault line. Researchers think the quake may have come from the Puente Hills fault which starts out in Los Angeles and runs through Orange County to the south. The Puente Hills fault was not even known about until its discovery in 1999, but it was making its presence known long before anyone knew it was there. It is believed to have triggered the large 1987 Whittier Narrows quake responsible for eight fatalities.
The Monday afternoon quake did not generate much damage if the reports to emergency workers are any indication. The LA Fire Department’s Margaret Stewart said they hadn’t received any complaints of big damage. Just to be sure, the department sent firefighters out to tour their coverage areas (there are 106 stations in LA) and give a more complete report.
Similarly, the California Highway Patrol did not receive any reports of car accidents or similar damage.
