From beneath Antarctica's Ross Sea, scientists retrieve pristine record of the continent's climate cycles

Frequent climate fluctuations on the world’s southernmost continent have been so extreme over the past 5 million years that Antarctica’s Ross Ice Shelf, a floating slab of ice the size of France, oscillated in size dramatically, and perhaps even disappeared for periods of time when the West Antarctic Ice Sheet may have been smaller, according to scientists engaged in an unprecedented international geologic drilling project.