California-Sized Area of Ice Melts in Antarctica
Pastor Dale Morgan
California-Sized Area of Ice Melts in Antarctica
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By LiveScience Staff
posted: 16 May 2007 04:12 pm ET
Warm temperatures melted an area of western Antarctica that adds up to
the size of California in January 2005, scientists report.
Satellite data collected by the scientists between July 1999 and July
2005 showed clear signs that melting had occurred in multiple distinct
regions, including far inland and at high latitudes and elevations,
where melt had been considered unlikely.
"Antarctica has shown little to no warming in the recent past with the
exception of the Antarctic Peninsula," said Konrad Steffen of the
University of Colorado, Boulder. "But now large regions are showing the
first signs of the impacts of warming as interpreted by this satellite
analysis."
Changes in the ice mass of Antarctica, Earth's largest freshwater
reservoir, are important to understanding global sea level rise. Large
amounts of Antarctic freshwater flowing into the ocean also could affect
ocean salinity, currents and global climate.
NASA's QuikScat satellite detected snowmelt by radar pulses that bounce
off of ice that formed when snowmelt refroze (just as ice cream turns to
ice when it is refrozen after being left out on the counter too long.)
Maximum high temperatures of 41 degrees Fahrenheit that persisted for
about a week in Antarctica caused a melt intense enough to create an
extensive ice layer.
Evidence of melting was found up to 560 miles inland from the open
ocean, farther than 85 degrees south (about 310 miles from the South
Pole) and higher than 6,600 feet above sea level.
Water from the melted snow can penetrate cracks and the ice, lubricating
the continent's ice sheets, sending them toward the ocean faster and
raising sea levels, the scientists said.
"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.
No further melting has been detected through March 2007.