SAN FRANCISCO, Aug. 12 (Xinhua) -- An earthquake measuring 6.1 on the Richter scale jolted an area 64km southwest of Kaktovik, a city in North Slope Borough, Alaska, at 14:58:53 GMT on Sunday, the U.S. Geological Survey said.

The epicenter, with a depth of about 9.9 km, was located at 69.624 degrees north latitude and 145.247 degrees west longitude.

The Alaska Earthquake Center said 13 aftershocks, measuring 3.1 and 4.9 on the Richter scale, respectively, were recorded.

No tsunami warnings were issued following Sunday's earthquake, according to the U.S. National Oceanic and Atmospheric Administration.

On Jan. 29, a 7.9-magnitude earthquake hit the Gulf of Alaska, which triggered a cellphone warning that a tsunami could hit the southern coast of Alaska, causing panic among residents in some communities.