A team of scientists from Lancaster and Durham Universities has monitored, for the first time, the evolution of meltwater ponds on the surface of a glacier at the coast of East Antarctica.
The team, led by Emily Langley at Durham University, used satellite observations at Langhovde Glacier to demonstrate the development of meltwater-related features, such as ponds and rivers – over a hundred of them in each summer between 2000 and 2013.
Melting of the ice surface is a common and significant process governing the loss of mass from the Greenland Ice Sheet. However, in Antarctica, and especially in East Antarctica where air temperatures rarely rise above zero, meltwater on the surface of the ice sheet is not often seen.
They observed that during a short summer period, air temperatures rise just above zero, allowing melting to occur, ponds to form, and rivers to develop, with the largest and deepest lakes occurring consistently when the temperatures are warmest.
They found that these lakes form nearly 20 km inland and meet their demise either by draining their contents into the ice beneath or by quickly freezing over at the end of the summer.
Study co-author Dr Amber Leeson, of Lancaster’s Environment Centre and the University’s Data Science Institute, said: “We show that more, and deeper, lakes form in warmer years. This is significant because the number of warm summers in East Antarctica is expected to rise as climate change continues.
“Although these lakes are probably too small to have a big effect on ice flow at present, our findings suggest that we should keep a close eye on them in coming years.”
In Greenland, similar – but more pervasive – lake formation has been found to affect the flow of the ice sheet, which can weaken it and make it more likely to break apart.
However, in East Antarctica, the impact that lakes have upon ice flow, ice loss and sea level change has not been considered until now.
The team predict that as the climate warms, these surface lakes in East Antarctica will become an important control over the fate of the ice sheet, as has been observed in Greenland over the last three decades.
The study was published online in Geophysical Research Letters.
Source: Lancaster University