A vigorous earthquake swarm began on Friday, April 18 at 10:44 am AKDT (18:44 UTC) in the western Brooks Range near the village of Noatak.

The largest events were felt strongly in Noatak and at the Red Dog Mine and as far away as Kotzebue. No major structural damage was reported, however some residents reported items falling off the shelves and cracks appearing in the walls and ceilings.