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The Big One earthquake may not be as big of one

(NewsNation) — In a potentially game-changing revelation, recent research challenges the widely held belief that the anticipated “Big One” earthquake along the San Andreas fault in Southern California could be as devastating as predicted.

The findings, presented at the American Geophysical Union, suggest that the earthquake’s impact may be considerably less severe than previously estimated, particularly in the Los Angeles area, Live Science reported.

Traditionally, earthquake risk models rely on historical data and ground motion recordings from past seismic events, often covering a limited timeframe. However, a team of researchers has turned to an unconventional source for insights — rocks. Located just 9.3 miles from the San Andreas fault in northern Los Angeles County, a cluster of five precariously balanced rocks has become a key focus of the study.

Analysis of these rocks, which have stood witness to seismic activity over the past 50,000 years, challenges existing hazard models. Lead researcher Anna Rood, a seismic hazard scientist at Imperial College London, explained that current earthquake recordings span less than 100 years, making predictions uncertain regarding the potential impact of rare, large earthquakes.

The study’s results indicate that ground shaking during the anticipated Big One could be up to 65% less intense than current hazard models suggest. While geophysicist Mark Petersen from the U.S. Geological Survey acknowledged the significance of the findings, he cautioned that it’s too early to incorporate them into updated maps.

It has been about three centuries since the last great earthquake on the southern San Andreas Fault, according to the New York Times.

Hazard maps play a crucial role in setting building codes, disaster preparation plans, and determining earthquake insurance premiums. If the precarious rock data is included in future map updates, it could have far-reaching implications for these decisions, according to Rood. While designing buildings with an abundance of caution is not necessarily a negative practice, it could result in unnecessarily expensive projects.