Antarctic expedition collects evidence that ice sheet melted during previous warm period

Analyses will help to reveal how far the West Antarctic Ice Sheet retreated in the past — and what it might do in the future.

Scientists have just got their hands on a 228-metre (748-foot) core sample from the muddy bedrock beneath West Antarctica’s chunky ice sheets. Inside the record-breaking sample, they discovered fossils of marine organisms that date from a time when this area was an open, ice-free ocean.