A magnitude-7.9 earthquake near Alaska's Aleutian Islands prompted a tsunami warning on Monday, but only small waves of several inches were observed along coastal communities. The National Tsunami Warning Center cancelled all warnings approximately four hours after the quake, which struck at 1:30 pm local time.
The earthquake's epicentre was located about 13 miles south-east of Little Sitkin Island, roughly 1,400 miles south-west of Anchorage. Despite the strength of the tremor, no damage was reported, according to Jeremy Zidek, a spokesman for the Alaska Department of Homeland Security and Emergency Management.
In Adak, one of the largest cities in the affected area, residents evacuated to higher ground as a precaution. City Manager Layton Lockett said the bay's water receded, prompting about 300 people to gather at the primary evacuation centre on Bering Hill. After the warning was lifted, Lockett noted that the community remained on alert, ready to respond if sirens sounded again.
A tsunami wave of about 7 inches was recorded at Amchitka Island, diminishing to a couple of inches at Adak and Shemya. The earthquake was widely felt in Adak, with shaking lasting longer than usual. Lockett described it as one of the top 10 most intense tremors in recent memory, causing vehicles to shake and residents to wait for it to end.
No damage occurred at Eareckson Air Station on Shemya Island, a US military early warning radar installation. Amchitka Island, where the US conducted nuclear tests in the 1960s and '70s, also reported no issues. The earthquake's magnitude was initially reported as 7.1, upgraded to 8.0, then downgraded to 7.9 after data review. Several strong aftershocks, up to magnitude 5.9, were recorded but deemed too small to generate a tsunami.
