For the second time in four months, a false-alarm alert about an earthquake was triggered in Northern California, and this was actually multiple alerts, but this time there thankfully were no loud alarms on cellphones rattling Bay Area residents awake.
The US Geological Survey has some questions to answer about a series of false alerts that were somehow triggered on its automated earthquake detection system Monday night in multiple locations. As the Chronicle reports, these included two off-shore earthquakes west of the Bay Area, as well as locations near Bonny Doon in Santa Cruz County, near Point Reyes, near Yreka, and near Shaver Lake in Fresno County.
The false alerts were for quakes ranging in size from 3.2M to 3.8M.
The Sacramento Bee, for instance, has this report, via the CA Earthquake Bot, showing an earthquake with a preliminary magnitude of 3.7 having struck offshore, 53 miles west-southwest of Bonny Doon, at 8:48 pm. If you look at the USGS earthquake site today, however, no such quake appears, and the only Bay Area quake in the last 24 hours was a 2.8M that struck just after midnight near San Ramon — the site of an ongoing earthquake swarm that began last fall.
As the Chronicle notes, the USGS's automated earthquake detection system can "occasionally produce erroneous readings due to signal interference or processing errors," but these instances are reportedly supposed to be "rare."
In early December, Bay Area residents were alarmed by an 8:06 am "Critical" earthquake warning about a 5.9M quake, pushed out to cellphones that subscribe to the ShakeAlert system with a blaring alarm sound, however the warning seemed immediately suspect because of the location of the false quake — which was centered in Lyon County, Nevada.
Even an earthquake of that size likely would not have been felt over 200 miles away in the Bay Area.
The USGS quickly retracted the report and issued an apology on X, saying "There was no M5.9 earthquake," and "We are currently looking into why the alerts were issued."
The incident prompted a rebuke from California politicians the following week, with Representative Kevin Mullin and four other Democratic House members writing to the USGS and saying, "The public relies on USGS for authoritative, real-time information during earthquakes," and this public trust is "essential." Governor Gavin Newsom also said that the error put a spotlight on the Trump administration's cuts to federal agencies like the USGS.
Per the New York Times, Christie Rowe, director of the Nevada Seismological Laboratory at the University of Nevada, Reno, put out a statement suggesting that "a faulty power system" at one of the seismic monitoring stations in Nevada was likely to blame for the false alarm.
The malfunction at that one station reportedly caused data transmission issues throughout the ShakeAlert system.
And this system is gaining a reputation for unfortunate glitches that can lead to widespread, if brief, panic. You'll recall that after the system went online, there was an earthquake drill scheduled for 10:19 am on October 19, 2023, but the loud alert instead went out seven hours early, at 3:19 am, to cellphones around the Bay Area.
The USGS blamed that one on a time-zone mix-up.
Previously: That 5.9M Earthquake Warning Out of Nevada Was Fake News
