Even Environmentalists Face Trade-Offs: Plans to Refill the Salton Sea May Hasten an Overdue Large Earthquake

(p. A1) 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 on Wednesday [June 7, 2023] 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.

. . .

Mr. Hill and his co-authors found that major earthquakes along the southern San Andreas fault tended to happen when a large body of water, Lake Cahuilla, was filling or was full with water from the Colorado River in what are now the Coachella and Imperial valleys.

The lake has drained over the last three centuries and all that remains is the vestigial Salton Sea.

. . .

The research published in Nature, which builds on a paper on which Dr. Philibosian was a writer in 2011, raises questions about plans to rehabilitate parts of the Salton Sea, . . . .  . . .  As the sea dries out, toxic dust is left behind and blown into the air, posing a hazard for nearby residents.

. . .

Impounding more water in the Salton Sea could tamp down the dust.Impounding more water in the Salton Sea could tamp down the dust.  . . .  But a major change in the water level could also trigger seismic activity, according to Dr. Philibosian.

For the full story, see:

Thomas Fuller. “Scientists Offer Reason for a Sleepy San Andreas Fault.” The New York Times, First Section (Sunday, June 11, 2023): A20.

(Note: ellipses, and bracketed date, added.)

(Note: the online version of the story has the date June 7, 2023, and has the title “The San Andreas Fault Is Sleepy Near Los Angeles. Researchers Have an Idea Why.”)

The Nature article published online on June 7 and mentioned above is:

Hill, Ryley G., Matthew Weingarten, Thomas K. Rockwell, and Yuri Fialko. “Major Southern San Andreas Earthquakes Modulated by Lake-Filling Events.” Nature (2023) DOI: 10.1038/s41586-023-06058-9.

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