Skip to main Content
Alaska News

Aftershocks, some big enough to feel, will follow Alaska earthquake

  • Author: Craig Medred
  • Updated: September 27, 2016
  • Published December 3, 2012

Editor's note: The following report was updated at 6:45 p.m. Monday.

At approximately 4:42 p.m. on Monday, a long-lived earthquake rumbled in Southcentral Alaska.

Officials say the quake's preliminary magnitude was 5.7, and its epicenter was 55 miles southwest of Palmer and 25 miles west of Anchorage at a depth of 33.5 miles. Since the first report, the magnitude has climbed to 5.9.

The Tsunami Warning Center has issued no watches, warnings or advisories, and expects no tsunami.

In calls coming into the center minutes after the quake happened, people mentioned the quake was large enough to cause objects to fall off shelves, but no major damage was immediately reported.

Staff at Alaska Dispatch headquarters at Anchorage's Merrill Field airport felt the waves go on for about a minute, but only light psychological damage occurred.

The earthquake, centered near the land-water border on the Northern end of Cook Inlet 18 miles northeast of Tyonek, was widely felt across Alaska -- throughout the Kenai Peninsula and in the Prince William Sound community of Valdez, north to Anchorage and the Mat-Su Valley. The quake was reportedly felt even hundreds of miles to the north, in the Interior's Golden Heart City, Fairbanks.

The Fairbanks-based Alaska Earthquake Information Center (AEIC) on late Monday had measured the quake as magnitude 5.75, lower than other preliminary estimates being made. Immediately after the rumbling ceased, magnitude estimates briefly went as high as 5.9. It's not unusual, AEIC said, for agencies to have somewhat varied data until they have time to finalize and coordinate information.

If the Monday quake got your attention, though, prepare for more shake-ups. Aftershocks are predicted to occur in decreasing magnitude until the energy from the initial event disperses, and some of them may be felt.

The AEIC uses an easy formula to estimate the number and size of aftershocks, but it can't predict when or where they will hit. Expect 10 aftershocks at magnitude 4.7, 100 at 3.7, 1,000 at 2.7 and so on, AEIC said Monday.

Did you feel the quake? Lose any dishes or whimsical glass curios? Sound off in the comments section below.

For more newsletters click here

Local news matters.

Support independent, local journalism in Alaska.