Researchers have discovered tens of thousands of meltwater lakes on the edge of the East Antarctic Ice Sheet. As you can no doubt imagine, that’s very worrying news.
Reporting in the journal Scientific Reports, geographers from Durham University and Lancaster University in the UK used high-res satellite imagery to document over 5 million square kilometers (1.9 million square miles) of the East Antarctic Ice Sheet during the summer of January 2017.
They found over 65,459 supraglacial lakes (bodies of meltwater that sit on top of glaciers) around the coastal edges of the ice sheet. While most were the size of an average swimming pool, the largest measured over 70 square kilometers (27 square miles).
Certain levels of thawing are to be expected this time of year as it’s during the melt season when temperatures often reach above zero and cause surface melting. Nevertheless, the researchers were surprised to discover the number of meltwater lakes forming.
“We’ve known for some time that lakes are forming in East Antarctica, but we were surprised at quite how many had formed and all around the ice sheet margin," lead author Professor Chris Stokes, in the Department of Geography, Durham University, said in a statement.
“The density of lakes in some regions is similar to the densities we’ve observed on the Greenland Ice Sheet and on the Antarctic Peninsula, which are generally viewed as much warmer,” he explained. “It’s concerning because we know that in other areas large numbers of lakes draining can fracture apart floating ice shelves, causing the inland ice to speed up.”
The East Antarctic Ice Sheet is the largest ice sheet on the planet. It was once considered relatively tough and resilient compared to its unstable neighbor, the West Antarctic Ice Sheet, whose base is below sea level and more vulnerable to rising sea temperatures. However, the East has recently been keeping scientists up at night. A number of new studies have shown that the East Antarctic Ice Sheet is also bearing the brunt of climate change, and is posed for further blows.
The new findings reaffirm the researchers' fear that the area could be more sensitive to the effects of a warming climate than previously believed.
“At the opposite end of the Earth, we’ve seen Greenland’s population of supraglacial lakes spread inland as air temperatures have risen, and we’re concerned about the potential implications for enhanced melting and ice loss there,” said co-author Dr Amber Leeson, of the Lancaster Environment Centre at Lancaster University.
"Until recently we assumed that East Antarctica was too cold to be similarly vulnerable, but this work shows that there may be closer parallels here to our observations on Greenland than previously thought.”
For more information on the state of the world’s oceans and ice-covered areas, the new Intergovernmental Panel on Climate Change (IPCC) report released this week makes for some comp[usive reading.