7.0 Earthquake Hits California Coast, Prompting Tsunami Warnings

7.0 Earthquake Hits California Coast, Spurring Aftershocks and Tsunami Warnings.

A powerful 7.0-magnitude earthquake struck near California’s coast at 10:44 a.m. Pacific Time on Thursday, with its epicenter located 62 miles west-southwest of Ferndale, according to the US Geological Survey (USGS). The quake triggered over 35 aftershocks within three hours, ranging from 2.5 to 4.7 in magnitude.

Harold Tobin, director of the Pacific Northwest Seismic Network, noted the ongoing activity, and the USGS predicts up to 130 aftershocks of magnitude 3 or higher within the week, with a 53% chance of quakes stronger than magnitude 5. The odds of another 7.0 or larger quake are estimated at 1 in 100.

The Fault Behind the Quake

The earthquake originated from the Mendocino triple junction, where the Pacific, North American, and Juan de Fuca tectonic plates meet. This region, at the intersection of the San Andreas Fault and Cascadia Subduction Zone, is highly active but typically produces quakes no larger than magnitude 7.

Historically, five magnitude 7+ quakes have occurred here in the past century. While Thursday’s quake could slightly raise stress on nearby faults, Tobin stated that the risk of triggering major earthquakes in adjacent zones remains low.

Tsunami Warning and Response

The quake initially triggered tsunami warnings and evacuations from northern California to southern Oregon, including the San Francisco Bay Area. The National Tsunami Warning Center canceled the alerts within an hour, as the strike-slip motion of the quake—primarily horizontal rather than vertical—did not displace enough water to generate a wave.

Tobin emphasized the importance of the precaution, saying such warnings are prudent until more data confirms the risk level.

Damage and Impact

The USGS reported a low likelihood of significant fatalities but noted the potential for localized damage. Governor Gavin Newsom declared a state of emergency for three Northern California counties near the epicenter, enabling faster resource allocation.

Initially, 10,000 homes and businesses in Humboldt County lost power, though fewer than 500 remained without electricity by Thursday afternoon, according to PowerOutage.us. Early damage assessments are ongoing, but no major updates have been provided.

Read Original Article: Science Alert

Read More: Scitke