An ongoing swarm of earthquakes, with the largest quakes measuring M6.3, M6.2 and M5.2, is currently rattling near Skagway, Alaska.
The two earthquake >M6.0 are the strongest to be felt in Southeast Alaska since a magnitude 7.5 earthquake centered west of Craig on Jan. 4, 2013. No reports of damages and no tsunami threat.
A series of strong quakes is currently hitting the Canadian-Alaskan border. Shaking was felt across hundreds of miles, from Petersburg to the center of the Yukon.
In downtown Whitehorse, the shaking set off alarms in at least one business, and small landslides were also observed from that city’s clay cliffs. Power was briefly disrupted in Whitehorse as well. By email, Yakutat resident Don Bremner said he was awoken by the 4:30 a.m. quake, and the following event two hours later “felt as if you were getting a dizzy spell in slow motion!”
According to the U.S. Geological Survey’s preliminary estimates, the first temblor was a magnitude 6.2 quake that hit at 4:31 a.m. (12:31 pm UTC) along the Haines Highway in British Columbia, between Haines Junction in the Yukon and Haines in Alaska.
Subsequent quakes followed in the Tatshenshini-Alsek Provincial Park area, the sliver of British Columbia between Southeast Alaska and the Yukon. The largest had a preliminary magnitude of 6.3 and happened at 6:18 a.m. (2:18pm UTC). A magnitude 5.2 quake was recorded at 4:49 a.m. (12:49 pm UTC), and there have been more than two dozen temblors with magnitudes between 2.5 and 4.5.
The National Tsunami Warning Center in Palmer issued a statement three minutes after the first quake, saying a tsunami was not expected. That expectation has been repeated after each earthquake.
Both strongest earthquakes came from the offshore Queen Charlotte-Fairweather fault, where the undersea Pacific plate slides northwest against the North American plate. Monday morning’s quakes appeared near the Eastern Denali Faultbefore splitting into the Chatham Strait Fault and the Coastal Shear Zone near the northern end of Lynn Canal.
Strong earthquakes are unusual in Southeast Alaska, but not rare. These earthquakes are the strongest to be felt in Southeast Alaska since a magnitude 7.5 earthquake centered west of Craig on Jan. 4, 2013. A magnitude 6.0 earthquake centered at Palma Bay, near Icy Strait, occurred in July 2014.