Two significant earthquakes that hit Alaska's remote Aleutian Islands were followed Friday morning by two smaller ones, but there were no reports of any damage or injuries. The earthquakes were likely aftershocks of a magnitude-7.2 earthquake that hit the seismically active but sparsely populated North Pacific island chain Tuesday, experts said. The magnitude-5.9 and magnitude-6.1 earthquakes hit about one minute apart Thursday night. They were centered about 160 kilometers west of Adak in the island chain, the U.S. Geological Survey said. Magnitude-4.8 and magnitude-4.6 earthquakes hit 14 minutes apart Friday morning. The Aleutian Islands are a chain of more than 300 islands that extend southwestward from mainland Alaska into the northern Pacific Ocean. The world's most active seismic feature, the circum-Pacific seismic belt, borders Alaska and the Aleutian Islands.
