WASHINGTON - Two strong earthquakes 40 minutes apart rocked the remote South Orkney Islands in Antarctica on Sunday, experts from the US Geological Survey said. The epicenter of the first, a magnitude 6.5 temblor, was at a depth of 10 kilometers (six miles), some 464 kilometers west of Coronation Island, the USGS said. No destructive tsunami was created, according to a US-based warning center. The quake occurred at 1340 GMT, and about 40 minutes later the region was struck by an aftershock measured at 6.2, according to USGS.