A new study by the National Aeronautics and Space Administration of the United States has found that a mantle plume – a geothermal source of heat located deep below Antarctica’s Marie Byrd Land – is why melting creates lakes and rivers under the ice sheet.

It is important to understand the sources and future of the meltwater under the ice sheet in West Antarctica to be able to gauge the rate at which the continent may lose ice to the ocean in the future. Although the mantle plume is not a new source of heat, it could help explain the ice sheet’s frightening instability today and why it melted at a faster rate in an earlier era of climate change.

Around 11,000 years ago during the last ice age, West Antarctica saw rapid sustained ice loss as global weather patterns changed and rising sea levels pushed warm water closer to it – we see a similar phenomenon today.

Mantle plumes are believed to be narrow streams of hot rock that rise through Earth’s mantle and spread out like a mushroom cap under the crust. The mantle plume under Antarctica’s Marie Byrd Land was formed 50 to 110 million years ago, much before the ice sheet in West Antarctic came into existence.