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 major earthquake with a preliminary magnitude of 7.3 initially triggered a tsunami warning for the southern Alaska Peninsula. It was later downgraded to an advisory.

Communities along a 700-mile (1,127-km) stretch of Alaska’s southern coast ordered their residents to higher ground Wednesday after a powerful earthquake prompted a tsunami warning. The 7.3-magnitude earthquake struck at 12:37 p.