7.7-magnitude quake off Northern Marianas, no tsunami alert

A strong but deep 7.7 magnitude earthquake struck off the Northern Mariana Islands in the western Pacific today, but triggered no tsunami alert, US monitors said.

The quake struck at a depth of 212 kilometre at 7:18 am (local time) some 31 kilometre southwest of the island of Agrihan, according to the US Geological Survey.

No tsunami warning was issued.