The second moderate earthquake in as many days struck the Aleutian Islands Wednesday, shaking up the 5,000 Navy personnel and dependents at Adak Naval Air Station but causing no damage or injuries.

It was followed within hours by two smaller and unrelated earthquakes that shook within a 40-mile radius of Anchorage, officials said.The Pacific Tsunami Warning Center said an earthquake with a preliminary reading of 5.1 on the Richter scale was centered 50 miles southeast of Adak, where officials at the Navy air base reported the jolt was felt strongly. The quake struck at 8:14 p.m.