A strong 7.8 magnitude earthquake shook the southern coast of Alaska last night, according to the U.S. Geological Survey (USGS). A resulting tsunami warning, that has since been canceled, advised coastal residents to head for higher ground.
The earthquake struck at around 10:12 pm local time at a depth of roughly six miles. The epicenter was located just over 61 miles south-southeast of Perryville, Alaska.
The National Weather Service’s (NWS) National Tsunami Warning Center in Palmer, Alaska, issued tsunami Warnings and Advisories for much of southern Alaska, the Alaska Peninsula, and the Aleutian Islands.
BULLETIN Public Tsunami Message Number 2 NWS National Tsunami Warning Center Palmer AK 1050 PM AKDT Tue Jul 21 2020 UPDATES ------- * Revised alert areas * Revised magnitude ...THE TSUNAMI WARNING REMAINS IN EFFECT... ...A TSUNAMI ADVISORY IS NOW IN EFFECT... Tsunami Warning in Effect for; * SOUTH ALASKA AND THE ALASKA PENINSULA, Pacific coasts from Kennedy Entrance, Alaska (40 miles SW of Homer) to Unimak Pass, Alaska (80 miles NE of Unalaska) * ALEUTIAN ISLANDS, Unimak Pass, Alaska (80 miles NE of Unalaska) to Samalga Pass, Alaska (30 miles SW of Nikolski) Tsunami Advisory in Effect for; * SOUTH ALASKA AND THE ALASKA PENINSULA, Pacific coasts from Cape Suckling, Alaska (75 miles SE of Cordova) to Kennedy Entrance, Alaska (40 miles SW of Homer) * ALEUTIAN ISLANDS, Samalga Pass, Alaska (30 miles SW of Nikolski) to Amchitka Pass, Alaska (125 miles W of Adak) including the Pribilof Islands For other US and Canadian Pacific coasts in North America, the level of tsunami danger is being evaluated. Further information will be provided in supplementary messages.
An alert issued at 11:19 pm warned a Tsunami Warning was in effect for the Pacific coast of southern Alaska and the Alaska peninsula from Kennedy Entrance to Unimak Pass and from Unimak Pass to Samalga Pass in the Aleutian Islands. A Tsunami Advisory was also in effect on the Alaska mainland from Cape Suckling to Kennedy Entrance and Samalga Pass to Amchitka Pass in the Aleutian Islands.
However, just over an hour later, another alert announced that tsunami warnings for these areas had been canceled. The wave generated by the earthquake “no longer posed a threat,” although some locations may continue to see small level sea changes.
A Tsunami Warning means people living in affected areas should “evacuate inland or to higher ground above and beyond designated tsunami hazard zones or move to an upper floor of a multi-story building depending on your situation,” according to the NWS.