A 6.1-magnitude earthquake was felt on Shemya just after 10am on Wednesday. Its epicenter was about 60 miles from the small Air Force base and about 20 from the unpopulated island of Attu. There have been no reports of injuries or damage.

The Aleutian Chain has seen a good deal of seismic activity in recent months. A 7.1-magnitude quake hit the central Aleutians in June, followed by a 6.8-magnitude aftershock in September. But according to seismologist Natasha Rupert with the Alaska Earthquake Information Center, today’s quake likely isn’t a related event.

Rupert adds that because there isn’t much seismic monitoring equipment out in the western Aleutians it will be difficult to track potential aftershocks from the quake in the area.