Two new studies: Surface of Antarctica 'swimming in meltwater'

Posted Apr 22, 2017 by Karen Graham
For the first time ever, the network of streams, ponds, and lakes across Antarctica's surface have been mapped, and the extent of the water flow is astounding and worrying to scientists.
The edge of the Nansen Ice Shelf in Antarctica.
The edge of the Nansen Ice Shelf in Antarctica.
NASA/Christine Dow
Possibly the earliest documentation of water on Antarctica was made in 1909 when Ernest Shackleton and his fellow explorers found they had to cross flowing streams and even a lake on the Nansen Ice Shelf on their way to reach the magnetic South Pole.
But now, polar scientists have gathered and collated any and all research, journal entries and images to bring our knowledge of surface meltwater on the continent's surface up to date, giving future researchers an accurate baseline for any further studies.
In one study, scientists have been poring over aircraft and satellite images of Antarctica from 1947 to the present. They identified 700 seasonal, distinct networks of ponds, channels, and streams flowing from all sides of the continent. Some were as close as 600 kilometers (373 miles) to the South Pole and at altitudes of up to 1,300 meters (4,265 feet).
The second study found that surface drainage has persisted for decades, moving water up to 120 kilometers (75 miles) from grounded ice onto and across ice shelves, feeding vast melt ponds up to 80 kilometers (50 miles) long. This surface river ends in a 130-meter (427 feet) wide waterfall that can drain the entire annual surface melt over the course of about seven days.
Both studies point out there is no clear evidence that suggests there has been an increase in the amount of meltwater produced over the time period they covered. However, the studies do provide a much-needed baseline for determining the spread of free-flowing water in the future, reports CBS News.
“These streams are something that requires more investigation,” said Paul Mayewski, director of the Climate Change Institute at the University of Maine and a climatologist who’s done significant fieldwork in Antarctica. Mayewski was not involved in the study but called it “impressive.”
Scientists monitoring conditions at the Carlini Base in Antarctica  say the average temperature ther...
Scientists monitoring conditions at the Carlini Base in Antarctica, say the average temperature there has increased by 2.5 degrees Celsius over the past century
“This is not in the future – this is widespread now and has been for decades,” says Jonathan Kingslake, a glaciologist at Columbia University’s Lamont-Doherty Earth Observatory, who led the research. “I think most polar scientists have considered water moving across the surface of Antarctica to be extremely rare. But we found a lot of it, over very large areas.”
Two research teams from the Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, along with colleagues in the department of Geography, The University of Sheffield, Sheffield, UK, as well as researchers from Italy, Korea, and NASA were involved in this first thorough study of the meltwater on the Antarctic surface.
The two studies were published in the online journal Nature on April 20, 2017:
Widespread movement of meltwater onto and across Antarctic ice shelves
Antarctic ice shelf potentially stabilized by export of meltwater in surface river