Los Angeles: An earthquake with a magnitude of 7.3 struck off the coast of Alaska on Wednesday, prompting a tsunami warning that was later withdrawn, according to the United States Geological Survey (USGS).

The tremor occurred at approximately 12:37 local time (20:37 GMT), with its epicentre located around 54 miles (87 kilometres) south of Sand Point, a small island town. The quake had a relatively shallow depth of 12.5 miles (20 km), which can intensify shaking.

Authorities initially issued a tsunami warning for coastal areas of southern Alaska and the Alaska Peninsula. This was later downgraded to an advisory before being cancelled altogether roughly two hours after the quake.

“The Tsunami Advisory is cancelled for the coastal areas of South Alaska and the Alaska Peninsula,” said the National Tsunami Warning Center (NTWC) in an official statement.

A small tsunami, with a maximum wave height of just 0.2 feet (6.1 centimetres), was recorded at Sand Point. Though the threat passed quickly, officials urged residents in potentially affected zones to remain cautious.

“Do not re-occupy hazard zones until local emergency officials indicate it is safe to do so,” the NTWC warned.

The main quake was followed by a series of aftershocks—more than a dozen in total—the strongest of which registered at magnitude 5.2, according to the USGS.

There were no immediate reports of significant damage or injuries.

Seismically active Alaska

Alaska lies on the seismically active Pacific Ring of Fire, an area known for frequent and powerful earthquakes. The region has a long history of major seismic events, including the devastating 9.2-magnitude quake of March 1964, the most powerful ever recorded in North America. That disaster triggered a tsunami that ravaged Anchorage and impacted the US west coast and Hawaii, resulting in significant loss of life and over $400 million in damages.

More recently, in July 2023, a 7.2-magnitude earthquake struck off the Alaska Peninsula, though it caused no major damage.