East Antarctica hosts the largest ice sheet on Earth, containing enough water to raise global sea levels by 52 metres, were it to fully melt. Yet it has puzzled scientists for decades how and why this ice sheet formed.
In fact, there are two interlinked mysteries. First, Antarctica became covered in ice around 34 million years ago – a period known as the Eocene-Oligocene transition – while the Arctic region stayed largely ice-free for another 25 million years or so.
