Experts worry as dazzling lakes form in Antarctica

Largest ice mass shows new-melt phenomena

In a new study, scientists who study the largest ice mass on Earth — East Antarctica — have found that it is showing a surprising feature reminiscent of the fastest melting one: Greenland.

The satellite-based study found that atop the coastal Langhovde Glacier in East Antarctica’s Dronning Maud Land, large numbers of “supraglacial” or meltwater lakes have been forming — nearly 8,000 of them in summer between the year 2000 and 2013. In some cases, just as in Greenland, these lakes appear to have then been draining down into the floating parts of the glacier, potentially weakening it and making it more likely to fracture and break apart.

This is the first time that such a drainage phenomenon has been observed in East Antarctica, the researchers say. It was previously spotted on the warmer Antarctic Peninsula and was likely part of what drove spectacular events there like the shattering of the Larsen B ice shelf in 2002.

When it comes to East Antarctica, however, “that’s the part of the continent where people have for quite a long time assumed that it’s relatively stable, there’s not a huge amount of change, it’s very, very cold, and so, it’s only very recently that the first supraglacial lakes, on top of the ice, were identified,” said Stewart Jamieson, a glaciologist at Durham University in the U.K. and one of the study’s authors.

The study was led by Emily Langley of Durham, who worked with Jamieson and Chris Stokes from her university and Amber Leeson of Lancaster University. The work was recently published online by Geophysical Research Letters.

The research raises concern, for the following reason: Mounting evidence suggests one reason that Greenland has been melting so fast lately is precisely these kinds of lakes. In the summer as air temperatures warm, lakes form on top of the ice sheet and on its fingerlike glaciers that extend outwards into deep ocean fjords.

These lakes can then suddenly disappear all at once or flow into rivers that drain into the ice below, lubricating the ice and helping to increase the lurch forward of glaciers. Sometimes, researchers have even been able to document fresh water flowing outward directly into the sea from the base of a glacier. That injection of cold fresh water into salty water can then create tornado-like underwater flow patterns at the submerged glacier front that cause further ice loss.

The occurrence of these lakes was strongly related to surface air temperatures: They formed when temperatures rose above zero Celsius, or, above freezing, and formed most frequently in the summer of 2012-2013, which saw 37 days with temperatures above the freezing point.

When glaciers lose large parts of their ice shelves, they become less stable and flow faster towards the ocean, contributing to an increased rate of global sea level rise.

PAULINE ASKIN/REUTERS FILE Two Adelie penguins stand atop a block of melting ice on a rocky shoreline at Cape Denison, Commonwealth Bay, in East Antarctica in 2010.