Noatak swarm winding down?
November 18, 2014

Matt Gardine

It's been nearly a month since the September 25 magnitude 2.9 earthquake that, at least for now, stands as the last event in the Noatak swarm. For Noatak residents, this must be a welcome change from the 460 earthquakes - many of them felt - that were recorded from April through July:


The Noatak swarm has been one of the more interesting sequences in an unusually busy earthquake year in Alaska. It began on the morning of April 18 with a pair of magnitude 5.7 earthquakes 12 minutes apart, felt strongly in Noatak and at the Red Dog Mine and as far away as Nome. A third M5.7 occurred on May 3, followed by a M5.8 on June 7 and another M5.7 on June 16:


Each of these earthquakes was followed by a vigerous aftershock sequence, including about 20 events with magnitudes of 4 or greater. Altogether, we located more than 500 aftershocks before the swarm appeared to wind down in September. You can read about our response to the swarm in the News-Miner here:

Our summary of the swarm, including information about the tectonic setting and source mechanism, is on our Notable Events page (here).