Magnitude 5.6 earthquake near Lake Minchumina is felt in Fairbanks and Wasilla

A magnitude 5.6 earthquake struck 27 miles northwest of Lake Minchumina at 3:07 am Thursday, according to the Alaska Earthquake Center at the University of Alaska Fairbanks.

More than 100 people sent "Did You Feel It?" reports to the U.S. Geological Survey, from Lake Minchumina to Fairbanks, 156 miles east of the epicenter, and as far away as Wasilla and Aniak. Neither agency's records mentioned damage or injuries as of Thursday evening.

The quake was about 3 miles deep in a sparsely settled area. Other than Lake Minchumina, the nearest places the center lists are Telida, 60 miles south; Tanana, 69 miles north; and Kantishna, 73 miles southeast.

The two reports from Lake Minchumina described the strongest shaking, rated between moderate and strong on the USGS intensity scale. Fairbanks sent 67 reports, Healy 10, and McGrath and North Pole five each.

Closer to the epicenter, an automated computer model estimated very strong shaking. That is a model's estimate, not reports from people there.

The USGS measured the quake at magnitude 5.0 using a different scale, but its catalog lists the center's 5.6 as the preferred figure.

USGS analysis indicates the blocks of ground on either side of a nearly vertical fault slid sideways past each other, a type of movement called strike-slip.

Quakes this size have hit the area before. The USGS catalog lists three of magnitude 5 or larger within about 60 miles since 1984, and a larger one, a magnitude 5.9 near Tanana, in 1958.

One aftershock, a magnitude 3.0, followed about two hours later. A USGS forecast issued Thursday afternoon gives a 40% chance of another magnitude 3 or larger within a week, a 7% chance of magnitude 4 or larger and less than a 1% chance of magnitude 5 or larger.