CSUB professor urges Kern County to plan ahead and follow drop, cover and hold on guidance

A new study is raising concerns about earthquake risk in Southern California, finding the southern San Andreas and San Jacinto faults are under some of the highest stress levels in a thousand years — conditions researchers say could increase the chances of a major earthquake involving multiple faults. While those faults are south of Kern County, CSUB associate professor Matthew Herman said the underlying issue is the same across California: stress continues to build along faults as tectonic plates move. He pointed to the 2019 Ridgecrest earthquake as a reminder that major quakes can strike on faults many people may not know. “We are right in the middle of where these earthquakes happen. We’re no different in many ways than parts of Los Angeles, parts of San Francisco, that are very close to dangerous faults,” Herman said. Earthquakes occur when stress builds underground over years, decades or even centuries. Eventually, rocks break and slip along a fault, releasing energy that causes the ground to shake. In the new study, researchers found the southern San Andreas and San Jacinto faults have built up extremely high levels of stress without a major rupture for more than 160 years. Researchers said those conditions could raise the likelihood of a large earthquake that involves multiple faults. Herman said the San Andreas may get the most attention, but it is not the only fault capable of producing a damaging earthquake. “We have thousands of napped faults, many of which have earthquake potential,” Herman said. “Now, Ridgecrest specifically is part of this broader plate boundary between the Pacific and North America. It actually acts very similarly to the San Andreas; the types of earthquakes it can have are very similar to those along the San Andreas.” Herman said that’s why people should pay attention regardless of how close they live to a well-known fault. “A large earthquake that’s far from us doesn’t affect us very much. A smaller earthquake that’s right under your house can have a really big impact,” he said. When it comes to what to do during an earthquake, Herman said one of the most common mistakes is running to a doorway. “It’s not something especially strong or structurally sound, and the swinging of the door can actually hurt you quite a bit if it’s shaking a lot in the earthquake. So it’s really important when that shaking happens to find cover, get under it, and hold on and make sure things don’t fall on you and hurt you,” Herman said. Herman said Kern County is better prepared than it was decades ago because of stronger building codes and newer construction, but he urged residents to make sure they have a plan and know what to do before the next quake hits.