AVO

A magnitude-4.7 earthquake hit the Fox Islands early Monday morning and was felt in Unalaska.

According to the Alaska Earthquake Center (AEC), at 12:21 a.m. an earthquake at a depth of about 53 miles hit 26 miles southeast of Unalaska. 

Natalia Ruppert, a seismologist with the AEC, said the quake was not unusual for the region.

"Last night's M4.7 occurred within a known source of earthquake activity," said Ruppert.

A magnitude 3.5 earthquake occurred at Great Sitkin Volcano on Friday.

Since then, seismic activity has returned to lower levels, and no eruptive activity has been detected at the volcano – located 26 miles east of the community of Adak.

Hans Schwaiger, a scientist with the Alaska Volcano Observatory (AVO), said it appears the shallow earthquake was an isolated event, although small local earthquakes have continued over the past day.

Following a series of flight-canceling explosions, activity at Shishaldin Volcano has decreased over the past three weeks.

Matt Haney, a geophysicist with the Alaska Volcano Observatory (AVO), said this marks a pause for the eastern Aleutian volcano's eruptive phase, which has been underway since late last year.

A magnitude-6.2 earthquake struck Wednesday night about 50 miles from Adak.

"To give you an idea of how large that is, you get only about 100 magnitude-6 earthquakes on the globe annually," said seismologist Ken MacPherson of the Alaska Earthquake Center. "So that's a fairly significant earthquake."

Adak residents felt the shallow earthquake, which followed a series of smaller quakes in the same area.

MacPherson also said there have been dozens of aftershocks.

Updated 01/20/20 at 10:30 a.m.

The Alaska Volcano Observatory (AVO) has decreased the Aviation Color Code to "orange" and Alert Level to "watch" for Shishaldin Volcano. 

Ash emissions declined greatly Sunday night and seismicity is currently low. A SIGMET warning from the National Weather Service is still in effect for the detached volcanic cloud drifting east-southeast over the Pacific Ocean.