Wednesday’s magnitude 7.3 earthquake off Alaska's Aleutian Islands chain struck in a region that has experienced a handful of powerful quakes within the last five years — including one that shook communities almost exactly two years earlier.

The quake that struck Alaska’s southern coast on Wednesday, July 16 is part of a larger sequence that may continue to unfold in destructive ways.

A lightly populated stretch of Alaska ’s southern coast was under a tsunami warning Wednesday after a strong earthquake was felt throughout the region, and officials in the Pacific Northwest were evaluating whether there was any threat to coastlines there. Early measurements put the quake’s magnitude at 7.3.