Antarctic ice loss between 1996 and 2006, overlaid on a Moderate Resolution Imaging Spectroradiometer (MODIS) mosaic image of Antarctica. The colors indicate the speed of the ice loss. Purple/red is fast. Green is slow. Image credit: NASA
Ice loss in Antarctica increased by 75 percent in the last 10 years due to a speed-up in the flow of its glaciers and is now nearly as great as that observed in Greenland, according to a new, comprehensive study by NASA and university scientists.
In a first-of-its-kind study, an international team led by Eric Rignot of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the University of California, Irvine, estimated changes in Antarctica's ice mass between 1996 and 2006 and mapped patterns of ice loss on a glacier-by-glacier basis. They detected a sharp jump in Antarctica's ice loss, from enough ice to raise global sea level by 0.3 millimeters (.01 inches) a year in 1996, to 0.5 millimeters (.02 inches) a year in 2006.
Rignot said the losses, which were primarily concentrated in West Antarctica's Pine Island Bay sector and the northern tip of the Antarctic Peninsula, are caused by ongoing and past acceleration of glaciers into the sea. This is mostly a result of warmer ocean waters, which bathe the buttressing floating sections of glaciers, causing them to thin or collapse. "Changes in Antarctic glacier flow are having a significant, if not dominant, impact on the mass balance of the Antarctic ice sheet," he said.
To infer the ice sheet's mass, the team measured ice flowing out of Antarctica's drainage basins over 85 percent of its coastline. They used 15 years of satellite radar data from the European Earth Remote Sensing-1 and -2, Canada's Radarsat-1 and Japan's Advanced Land Observing satellites to reveal the pattern of ice sheet motion toward the sea. These results were compared with estimates of snowfall accumulation in Antarctica's interior derived from a regional atmospheric climate model spanning the past quarter century.
We first found out about this story via the guys at sciencedailycom/. The California Institute of Technology at Pasadena who manage the Jet Propulsion Laboratory for NASA issued a press release earlier this year.
Thanks to a collaboration between the British Antarctic Survey (BAS) and the Technical University of Braunschweig (TUBS), last month the BAS used unmanned air vehicles (UAV's) to collect data and help research in Antarctica for the first time. Whilst they are used for a variety of purposes around the world at the moment, this was the first time that they had been used in Antarctica.
Dr Phil Anderson of BAS says, "This is a huge technological achievement for BAS and TUBS. Apart from take-off and landing, when the UAVs are controlled by radio, the aircraft are completely autonomous, flying on their own according to a pre-programmed flight plan. Each flight lasts for 40 minutes, covering around 45 km and taking 100 measurements a second, so waiting for the UAV to return safely after its research mission was very exciting. Seeing the first UAV come back successfully was a real heart-in-the-mouth moment."
Each UAV has a wingspan of 2m and weighs 6kg. They are electric powered, using state-of-the-art Lithium Ion Polymer (LIPo) battery packs. Electric power ensures that the aircraft are suitable for both atmospheric physics and chemistry studies. Take off is by catapult and landing by skis onto snow, and a modified Tucker Snocat is used as "mission control".
The four UAVs were transported to BAS's Halley research station on the Brunt Ice Shelf on board BAS's Royal Research Ship Ernest Shackleton in late 2006. Scientists from BAS and the Technical University of Braunschweig (Germany) then spent 10 months testing the UAVs and perfecting safe take offs and landings before the first successful data-gathering flight on 30 October 2007.
According to Anderson, "UAVs allow scientists to reach the parts others cannot reach - the future of much atmospheric research will be robotic."
We first found out about this story via the guys at sciencedailycom/. Click here to read the British Antarctic Survey's press release.
Scientists in New Zealand and Australia have combined to publish work on whether some species of giant daisies known as Pleurophyllum arrived from Antarctica. The flowers, known to researchers as megaherbs, grow abundantly on the tiny windswept islands such as the Snares, Auckland and Campbell island groups. The research has been published on the online Nature Precedings pre-print service.
"There's always been a great deal of discussion about how plants spread in the southern hemisphere and the extent to which Antarctica has been important in this," says co-author Chris Quinn from the Royal Botanic Gardens in Sydney.
As the ice age began some 1.8 million years ago, conditions on Antarctica itself became inhospitable to many plants.
But the small islands further north offered a haven for survival just beyond the icy reach of the glaciers, the authors say.
Click here for the story from the Discovery Channel website.
Click here to read the research paper itself at Nature Precedings.
This year on April Fools Day the BBC went one further than the spaghetti trees of yesteryear - they created flying Adelie penguins.
Click here to watch them in action and to find out how it was done.
Norwegian sailor Oyvind Tangen has managed to take some beautiful pictures of striped icebergs whilst on board a research ship 660 miles north of Antarctica.
According to the article: "When an iceberg falls into the sea, a layer of salty seawater can freeze to the underside. If this is rich in algae, it can form a green stripe.
Brown, black and yellow lines are caused by sediment, picked up when the ice sheet grinds downhill towards the sea."
Click here for the story and more pictures from the Daily Mail.
The Lost Men