An earthquake of magnitude 6.8 hit off the main Japanese island of Honshu, the U.S. Geological Survey said on Tuesday.USGS originally reported the earthquake to be 6.9 magnitude.The quake was centered 74 miles (119 km) southeast of Morioka, Japan, at a depth of 24 miles (39 km), it said.There was no threat of a tsunami from the earthquake, according to the Pacific Tsunami Warning Center.DETAILS TO FOLLOW...