The melt, shown here in yellow and red, affected a combined region the size of California and amounts to the most significant Antarctic thaw seen from space in 30 years.
Using the QuikScat weather satellite, a team of scientists from NASA's Jet Propulsion Laboratory and the University of Colorado at Boulder detected the melt while mapping snowfall patterns from 1999 to 2005.
Data from the satellite revealed that vast fields of snow had thawed and refrozen during the Southern Hemisphere's summer of '05, when temperatures reached highs of 41 degrees Fahrenheit (5 degrees Celsius).
While melting has been observed on the Antarctic Peninsula (center left), the newly discovered thaws took place farther inland and at higher elevations, where melting was not expected.
"Antarctica has shown little to no warming in the recent past with the exception of the Antarctic Peninsula, but now large regions are showing the first signs of the impacts of warming as interpreted by this satellite analysis," said Konrad Steffen, director of Boulder's Cooperative Institute for Research in Environmental Sciences, in a statement.
The warm spell did not last long enough for the meltwater to flow into the ocean, the researchers noted.
But a longer melt of such severity could create enough water to seep beneath Antarctic ice sheets and send them sliding into the sea, they added.
"Increases in snowmelt such as this in 2005 definitely could have an impact on larger scale melting of Antarctica's ice sheets if they were severe or sustained over time," Steffen said.
Source: http://news.nationalgeographic.com/news/2007/05/070516-antarctica.html
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