Listening to Distant Ice Crack

摘要

Using satellites, scientists have kept a wary eye on the crumbling Antarctic ice shelf, tracking the movement of titanic chunks that break free. Now, using acoustic instruments designed to detect nuclear explosions, they are putting an ear to the ice as well. Big breaks in the ice shelf over the past 2 decades have been dramatic, but it remains unclear whether they are due to global warming. That's partly because most cracks and breaks are too small to be seen from space. Getting a statistical handle on those smaller events, said polar scientists at the meeting, will help determine whether the rate of ice-shelf degradation stays within natural bounds or steadily increases.