Massive earthquake hits Alaska: Tsunami warning issued

A massive M 7.8 earthquake that hit off the coast of Alaska, forced authorities to issue a tsunami warning.

The seismic shock occurred on July 22, 2020, at 10:12 p.m. local time. Its magnitude was M 7.8, according to the United States Geological Survey (USGS), and its epicenter was located about 96 kilometers southeast of Perryville, situated in the Alaska Peninsula. 

The earthquake was relatively shallow as it struck at a depth of 27 kilometers on a thrust fault located near or on the boundary plate between the North American and the Pacific plates. In the area that it took place, the Pacific Plate subducts under the North American Plate at a rate of 64 millimeters per year.

People in Alaska living in a 160-kilometer area from the epicenter, reported strong shaking while the tremblor was felt as far as 800 kilometers away near Anchorage. Nevertheless, fortunately, there have been no reports about victims or severe infrastructure damage associated with the event.

A warning for a potential tsunami threat was issued after the seismic shock for the Alaska Peninsula and South Alaska. People in coastal areas were evacuated from their residences and sent to higher ground. There were no alerts about potentially hazardous areas in Canada.

Schools in local communities were transformed into shelters to accommodate the people who evacuated their houses. Due to the COVID-19 spread, all of them were advised to wear masks and obey social distancing.  “We’ve got a high school full of people. I’ve been passing out masks since the first siren sounded. Everything’s as calm as can be. We’ve got probably 300, 400 people all wearing masks., Larry LeDoux, superintendent of the Kodiak Island Borough School District, stated.

The alert was canceled a few hours later with officials mentioning that there was indeed a small tsunami event but its impact was subtle. "A tsunami was generated by this event, but no longer poses a threat. Some areas may continue to see small sea level changes,” the U.S. National Tsunami Warning Center reported.

The main event was followed by more than 20 aftershocks between M 2.8 and M 6.1 which hit on the following day with minor impact.

In 1964, Alaska was struck by the largest ever recorded earthquake in North America. The M 9.2 event shook the region for a stunning duration (about 5 minutes) and triggered a 35-meter tsunami. 131 people were reported dead while the total infrastructure damage was estimated at $2.3billion