An earthquake measuring 5.1 on the Richter scale jolted 107 km South of Kokopo, Papua New Guinea at 00:15:39 Hong Kong Time on Wednesday (16:15:39 GMT on Tuesday), the U.S. Geological Survey said. The epicenter, with a depth of 64.22 km, was initially determined to be at 5.3099 degrees south latitude and 152.0966 degrees east longitude.