False Report of 5.9 Magnitude Earthquake Sends Phones Buzzing in Nevada

An alert that Nevada had been rocked by a 5.9 magnitude earthquake early Thursday sent phones buzzing briefly before the U.S. Geological Survey quickly deleted the warning from its website and said it had been sent in error.

“The event did not occur, and has been deleted from USGS websites and data feeds. The USGS is working to understand the cause of the false alert,” the agency said.

The alert for what would have been one of the largest earthquakes in the United States this year set off a chain of automatic warnings as far away as the San Francisco Bay Area as people in Dayton, Nevada, and nearby Reno began to report that they had felt no shaking.

The alert was released by a USGS tool called ShakeAlert that is designed to warn people about earthquakes before they feel shaking. It was unclear what prompted the false alert, which said the earthquake had occurred at 8:06 a.m. local time. Within minutes, some news outlets published stories detailing the earthquake’s reported location and strength, and fake images of destruction began spreading on social media.

Jon Bakkedahl, the emergency manager for Carson City, Nevada, said local officials were trying to figure out what had triggered the false alert, but had not heard anything from the USGS.

He said that regional emergency management officials had just sprung into action and were preparing to check buildings for damage when they learned from the Nevada Seismological Laboratory at the University of Nevada, Reno, that there had been no actual earthquake.

“It was a false alert, and we’re trying to figure how and why,” Bakkedahl said in an interview. He added that once word went out that it was a false alarm, regional emergency management officials were able to “quell everyone’s expectations and slow everything down.”

Taylor Allison, the emergency manager in Lyon County, Nevada, said that residents had started calling 911 after they got the alert on their phones. Lyon County includes Dayton, where the alert had claimed that the epicenter was located.

“We were ready to activate damage assessments” before the county confirmed that it was a false alarm, Allison said.

In general, several sensors must detect shaking to trigger an alert from the USGS, according to Graham Kent, a seismologist and director emeritus of the Nevada Seismological Laboratory.

But after the alert Thursday morning, staff members at the lab quickly looked at their instruments, “and there was nothing there,” Kent said. Not only that, he said, “we were all close enough, we would have just have felt it.”

A 5.9 magnitude earthquake would have been strong enough to knock objects off shelves, cause damage to older brick buildings and crack the stucco or siding on wood-frame houses, Kent said.

He said he wanted to know more about why the system, designed to give people time to find safe shelter during an earthquake, had failed.

“There has been a lot of successful reporting using the ShakeAlert system in the last few years, so we’re headed in the right direction,” Kent said. “This isn’t a good look.”

The messages people in Nevada and California received on their mobile phones were created by ShakeAlert. The system is designed to detect earthquakes as soon as they start, through tens of thousands of seismic stations buried under the ground in California, Oregon and Washington, the only states that are part of the network. These stations quickly gather information to determine which areas are likely to experience strong shaking.

The MyShake app uses the data to send early earthquake warnings. The Wireless Emergency Alerts system (the same technology used to send Amber Alerts) also delivers early earthquake warning messages to cellphones.

ShakeAlert, the only warning system of its kind in the nation, was introduced in California in 2019 and was expanded to Oregon and Washington in 2021, serving some 50 million residents and visitors.

Angie Lux, project scientist for Earthquake Early Warning at the Berkeley Seismology Laboratory, said this was the first time that ShakeAlert had falsely reported an earthquake. The USGS also has a traditional seismological network and it has reported false earthquakes in the past.

Nevada is not part of the ShakeAlert network, but large earthquakes in states outside the network can trigger the system, according to Christie Rowe, director of the Nevada Seismological Laboratory. On Thursday, people in California, more than 200 miles from the epicenter of the false quake, received alerts through the system. People in Nevada received Wireless Emergency Alert through ShakeAlert.

“We’re advocating to be covered,” Rowe said, but Nevada is “not covered yet.”