ScienceDaily: By studying rocks at different elevations beside the East Antarctic Ice Sheet (EAIS), a New Zealand-led team concluded that a period of rapid glacier thinning occurred in the recent geological past, and persisted for several centuries. Satellite observations show that parts of the Antarctic ice sheet are currently thinning in response to a warming ocean. Of particular concern is the potential for 'marine ice sheet instability', where an initial retreat of ice margins into deepening valleys could...