An earthquake measuring 6.5 on the Richter scale jolted 71 km north east of Nuku`alofa, Tonga at 14:02:16 Hong Kong Time (06:02:16 GMT) on Saturday, the U.S. Geological Survey said. The epicenter, with a depth of 10.0 km, was initially determined to be at 20.7173 degrees south latitude and 174.6735 degrees west longitude.