A significant underwater earthquake off the Humboldt/Mendocino Coast was expected to cause tsunami effects and coastal indundation starting after noon in San Francisco, but the tsunami warning has been lifted.

The earthquake struck, with a preliminary magnitude of 7.3, at 10:44 am, in the Pacific at a depth of 8 miles, about 45 miles southwest of Eureka, California. The USGS has subsequently revised the magntitude to 7.0.

Effects of a possible tsunami were expected to reach San Francisco's coast by 12:10 pm. The San Francisco Emergency Management Department put out a warning for residents to move at least one city block inland from all beaches, marinas, and piers, and to stay off all beaches, docks, and piers.

As the Chronicle reports, the USGS said in a conference call with the media that the tsunami warning was cancelled as of noon. "The only tsunami wave detected was off Marina Cove, and it was just 10 cm in height. No other tsunami waves have been detected at any offshore buoy sites," the USGS said, per the Chronicle.

Tsunami warnings were also issued for Hawaii, Samoa, and Guam.

The National Tsunami Warning Center subsequently sent out the alert, which applies to the entire Pacific Coast from Davenport, California, in Santa Cruz County, to Douglas/Lane Line in Oregon.

"Tsunami warnings mean that a tsunami with significant inundation is expected or occurring," the warning says. "Warnings indicate that widespread dangerous coastal flooding accompanied by powerful currents are possible and may continue for several hours after the initial wave arrival."

In recent past tsunami events, like one triggered by the January 2022 volano in Tonga, beaches were inundated and areas around Santa Cruz Harbor flooded. But this is the first tsunami warning we've had in the Bay Area in recent memory for a large earthquake occurring so nearby.

There are a couple of reports on X on damages on the ground in Ferndale, including a collapsed front door at the Victorian Inn.

This is a developing story.