Why San Andreas Fault is ‘sleeping’

Birds hunting for food during sunset at the Salton Sea in Desert Shores, California, United States. ­— ©2023 The New York Times Company

IT has been about three centuries since the last great earthquake on the southern San Andreas Fault, the most treacherous seismic hazard in California. For decades researchers have puzzled over why it has been so long. The average interval of large earthquakes along that portion of the fault has been 180 years over the past 1,000 years.

While seismologists agree that Southern California is due for the Big One, a group of researchers published a paper recently in the journal Nature that offers a reason for the period of seismic silence along the southern San Andreas, the tension-wracked meeting point of the North American and Pacific tectonic plates.