Series of earthquakes off Aleutian Islands builds to magnitude 6.4

An escalating series of earthquakes Monday off the Aleutian Islands wasn't expected to produce tsunami activity, according to the National Tsunami Warning Center.

An earthquake at 9 a.m. with a preliminary magnitude of 6.4, according to the Alaska Earthquake Center, struck at a depth of 7 miles about 82 miles west of Adak.

Natalia Ruppert, an AEC seismologist, said the center had been tracking a series of lesser shocks off Adak, including 5.2 and 5.7 quakes roughly 80 miles south of Adak at 7:31 a.m. and 7:47 a.m. Both temblors struck at a depth of about 25 miles.

"At this time the activity's still ongoing," Ruppert said.

[Magnitude 5.2 earthquake shakes Southcentral Alaska]

Ruppert said the quakes were likely felt in Adak, but the center hadn't heard any immediate reports from the remote community.

The center is continuing to monitor quakes in the area Monday.