Durham University: Understanding surface melting around the world’s largest ice sheet

A first-of-its-kind study led by our Department of Geography has investigated the formation of surface meltwater lakes around the world’s largest ice sheet, offering new insights into the potential impact of recent climate change on the ‘Frozen Continent’.

Mapping meltwater from space
The East Antarctic Ice Sheet is the world’s largest ice mass and holds enough ice to raise global sea levels by around 52 meters.

This study, which has been published in the journal Nature Communications, used over 2000 satellite images from a seven-year period (2014-2020) to study the size and volume of meltwater lakes forming on top of the ice sheet, also known as supraglacial lakes.

This is the first time that a year-on-year comparison of these lakes has been undertaken, providing experts with the opportunity to understand how the size and volume of the lakes varies annually, and how climate influences these changes.

Changing meltwater lakes
The team found that the volume of the meltwater lakes varied by as much as 200 per cent on individual ice shelves (floating extensions of the main Antarctic ice sheet) year-on-year, and by around 72 per cent overall.

Lakes were also found to be deeper and larger in warmer melt seasons and formed on some potentially vulnerable ice shelves.

Understanding ice shelf stability
As a result of climate change, air temperatures are expected to continue to rise in Antarctica, which the team argue will lead to an increase in the number and volume of meltwater lakes around its edges, which in turn may threaten the future stability of some of East Antarctica’s ice shelves (floating extensions of the main ice sheet).

This study will help experts understand why and where lakes grow around the ice sheet and to consider which ice shelves may be most at risk of collapse from surface melting in future.

The loss of ice shelves fringing an ice sheet allows ice further inland to flow faster into the ocean, contributing to global sea-level rise.

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