Preliminary magnitude 7.8 earthquake strikes off coast of Alaska

The quake was centered 60 miles, or 98 kilometers, south-southeast, of Perryville, Alaska. It is considered shallow at about 10 kilometers deep.

An earthquake with a preliminary magnitude of 7.8 struck off the coast of Alaska early Wednesday morning.The earthquake was centered 60 miles, or 98 kilometers, south-southeast, of Perryville, Alaska,according to the US Geological Survey. 

The quake is considered shallow at about six miles, or 10 kilometers, deep.”Anything below 70 kilometers is considered a shallow quake,” CNN meteorologist Allison Chinchar previously said. “That’s important, because shallow earthquakes often cause the most damage, compared to the ones that are deeper, regardless of the strength.”

A tsunami warning had been issued following the earthquake, according to the National Oceanic and Atmospheric Administration. The warning was in effect for south Alaska and the Alaska peninsula — Pacific coasts from Kennedy Entrance, Alaska (40 miles southwest of Homer) to Unimak Pass, Alaska, according to the Tsunami Warning Center.

From US Geological Survey: Access link below for additional information.

But all tsunami warnings and advisories were canceled early Wednesday morning, according to the National Weather Service.

Earthquakes are more likely to develop into tsunamis if they are high in magnitude, are shallow, and are thrust earthquakes rather than strike slip earthquakes, according to the USGS. Quakes between magnitudes 7.6 to 7.8 have the potential to produce destructive tsunamis.There have been at least 11 after shocks ranging from magnitudes of 3.9 to 6.1, according to CNN meteorologist Pedram Javaheri.

Source: CNN. USGS