A magnitude-6.4 earthquake hit about 25 miles east of Nikolski Tuesday morning, and was felt by residents in Nikolski, Unalaska, and Akutan. The earthquake hit just before 7:30 a.m.
It was a "reasonable size tectonic earthquake," according to Dave Schneider, a geophysicist with the Alaska Volcano Observatory. He said Aleutian Island residents can expect to feel some aftershocks.
"This is a pretty typical tectonic earthquake for the region," he said. "It's on a very seismically active part of the Aleutian arc, and there's nothing that jumps out as being unusual."
Schneider said the earthquake was not related to volcanic activity at Makushin Volcano, where a series of significant earthquakes hit over the summer. He said that activity has waned over the past several months.
"It's pretty common when people feel a tectonic earthquake to worry about whether or not it'll trigger additional activity at nearby volcanoes," Schneider said. "That's extremely rare, and it's only happened with larger earthquakes. And even in those cases, it's pretty minor elevation in seismicity."
Scientists at the AVO will continue to monitor activity at Makushin, said Schneider, but said he doesn't expect abnormal activity.
As of 1:30 p.m. on Tuesday, there had been eight "felt reports" on the U.S. Geological Survey's website.