On Monday, San Diego experienced a 5.2 magnitude earthquake, which was felt widely across the region. Fortunately, there were no reported injuries or major damage, although the quake served as a reminder of the need for ongoing earthquake preparedness. Jade Hindman from KPBS Midday Edition spoke with seismologist Alice Gabriel from UCSD Scripps Institution of Oceanography to discuss the geology behind earthquakes and what residents can do to be better prepared for future events.
Gabriel explained that California is prone to earthquakes due to its many fault lines which are areas of weakness in the Earth’s crust caused by the movement of tectonic plates. Over time, these faults accumulate strain until they release energy in the form of an earthquake. The recent quake, described as a moderate earthquake, was the largest in the region since 2010. Gabriel noted that the San Andreas Fault zone is a particularly dangerous structure that is monitored closely due to its proximity to major population centers like San Diego and Los Angeles.
Although the recent earthquake was measured at a 5.2 on the magnitude scale, Gabriel explained that the logarithmic nature of this scale means that a shift from a magnitude five to a magnitude six indicates an earthquake with 32 times more energy released. Thus, while a 5.2 quake might have rattled dishes and caused minor disturbances, a magnitude six earthquake could be significantly more destructive. The US Geological Survey reported that the earthquake was moderate, and people primarily felt the shaking as a loud boom followed by rattling.
In the aftermath, it was reported that over 100 aftershocks occurred, including a notable 3.9 aftershock later the same day. Gabriel mentioned that aftershocks are essential for seismologists as they help highlight which parts of the fault system moved during the main event and provide data necessary for further analysis. While some people felt aftershocks immediately, Gabriel assured listeners that the likelihood of a larger earthquake following was statistically low.
Regarding tsunami risks, Gabriel clarified that the earthquake’s inland location—120 miles from the Pacific Ocean—means that residents need not worry about tsunami warnings following this event. Tsunamis typically result from underwater earthquakes that can significantly displace the seafloor and trigger large waves, but since this earthquake occurred inland, there was no potential for such a tsunami.
The discussion then shifted to preparedness. Gabriel strongly recommended that residents subscribe to ShakeAlert, California’s earthquake early warning system. The system operates through a network of sensors that can detect early seismic activity and send warnings to inhabitants, potentially providing seconds of notice to seek shelter. Gabriel noted that this warning system can be particularly crucial since earthquakes generally strike without warning, catching many individuals off guard.
Before wrapping up the conversation, Hindman welcomed Jacob Margolis, a science reporter for LAist public radio and host of the podcast The Big One: Your Survival Guide, to share insights on how homes can be better prepared for earthquakes. Margolis reinforced Gabriel’s advice and underscored the importance of developing an emergency plan, particularly for families with children. He advised against attempting to run outside during an earthquake, recommending instead to seek shelter under a sturdy table or desk where possible.
Safe spaces inside homes might include areas away from windows or heavy objects that could fall. Margolis also emphasized the importance of preparedness kits, including supplies like water and food, as well as additional medication. It is vital to have a plan to ensure that both individuals and families will be safe from immediate harm during an earthquake, as well as equipped to survive in the aftermath.
He explained the challenges of predicting catastrophic earthquakes, asserting that while some warning systems exist, the unpredictability of earthquakes necessitates personal readiness. He elaborated on the various vulnerabilities of building structures during earthquakes. Unreinforced masonry and non-ductile concrete buildings are particularly susceptible to severe damage during strong quakes. Margolis noted that these types of structures, even if slightly damaged, can pose serious psychological issues for occupants who may feel unsafe to return after tremors.
Recognizing that children may be particularly affected by earthquakes, Margolis suggested engaging them in discussions about the science behind earthquakes to help normalize the fear associated with them. By incorporating earthquake drills into family activities, participants can better recognize the need for safety when an earthquake occurs. Ultimately, the conversation highlighted the reality of living in an earthquake-prone area, emphasizing that preparation is not merely a precaution, but a necessary aspect of life in California.
As listeners processed this important information, the overarching takeaway was clear: while the seismic activity may be unsettling, understanding how to prepare and protect oneself can instill a sense of security and confidence for the community. Looking ahead, residents are reminded that being prepared and educated can make all the difference when an earthquake strikes.
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