Powerful 7.3 magnitude earthquake jolts off Alaska Coast

A powerful 7.3-magnitude earthquake struck off the southern coast of Alaska on Wednesday, triggering immediate tsunami warnings that were later rescinded. The U.S. Geological Survey (USGS) confirmed the tremor occurred at 12:37 a.m. local time (2037 GMT), with the epicenter situated 87 kilometers (54 miles) south of Sand Point.

The quake originated at a shallow depth of 12.5 miles, intensifying its felt impact. The National Tsunami Warning Center (NTWC) initially issued a tsunami warning for South Alaska and the Alaska Peninsula, prompting precautionary measures across coastal regions.

Roughly two hours later, NTWC downgraded the warning to an advisory before eventually cancelling it entirely. “The Tsunami Advisory is canceled for the coastal areas of South Alaska and the Alaska Peninsula,” the center announced in an official bulletin.

While the earthquake caused only a minor tsunami wave of 6.1 centimeters (0.2 feet) at Sand Point, over a dozen aftershocks were recorded in its aftermath. The strongest aftershock registered at 5.2 magnitude, according to USGS data.

Authorities urged residents in coastal hazard zones to remain cautious. “Do not re-occupy hazard zones until local emergency officials indicate it is safe to do so,” the NTWC warned.

No immediate damage or casualties have been reported. However, the event underscores Alaska’s vulnerability as it lies within the seismically volatile Pacific Ring of Fire, an area notorious for frequent and intense tectonic activity.

This latest quake follows another 7.2-magnitude earthquake recorded off the Alaska Peninsula in July 2023, which similarly prompted tsunami warnings but resulted in no significant damage.

Alaska has a long history of seismic activity. The 1964 Great Alaska Earthquake, measured at 9.2 magnitude, remains the most powerful quake in North American history, unleashing a tsunami that ravaged Anchorage, parts of the U.S. West Coast, and Hawaii, claiming many lives and causing over $400 million in damages.