Between july and november 2002 researchers picked up acoustic signals of unprecedented clarity when recording seismic signals to measure earthquakes and tectonic movements on the ekstroem ice shelf on antarctica ' s south atlantic coast 2002年7月至11月,科学家在南极洲南大西洋沿岸的埃克斯特伦陆架冰地区记录地震信号时,却意外接收到了异常清楚的声音信号。