Alaska's Aleutian islands rocked by second quake

A second earthquake in less than 24 hours shook Alaska's desolate Aleutian Islands Tuesday measuring a magnitude of 6.3, US seismologists said.

The quake hit some 75 miles (120 kilometers) from Nikolski off the coast at a depth of some 8.5 miles (13.7 kilometers) at 12:21 pm Tuesday (2021 GMT), the US Geological Survey reported.

It came after a 6.2-magnitude earthquake struck the islands late Monday at 9:37 pm (0537 GMT Tuesday) about 91 kilometers (57 miles) southwest of Unalaska, a town of about 4,000 people, according to the USGS.

A message from the West Coast and Alaska Tsunami warning center said the second quake was not expected to trigger a tsunami.

"However, in coastal areas of intense shaking, locally generated tsunamis can be triggered by underwater landslides," the center added in a statement.

There were no immediate reports of injuries or damage. The chain of about 300 small islands with dozens of volcanoes sits on the Pacific ring of fire and is often subjected to seismic activity.

The readings were based on the open-ended Moment Magnitude scale, now used by US seismologists, which measures the area of the fault that ruptured and the total energy released.