BEIJING, Feb. 16 (Xinhua) -- An earthquake measuring 5.2 on the Richter scale jolted 20km SW of Adak, Alaska at 00:00:15 GMT on Thursday(local time), the U.S. Geological Survey said.

The epicenter, with a depth of 56.93 km, was initially determined to be at 51.7336 degrees north latitude and 176.8422 degrees west longitude.