Some Antarctic ice is forming from bottom
(ScienceDaily, 3 March 2011) -- Scientists working in the remotest part of Antarctica have discovered that liquid water locked deep under the continent's coat of ice regularly thaws and refreezes to the bottom, creating as much as half the thickness of the ice in places, and actively modifying its structure. The finding, which turns common perceptions of glacial formation upside down, could reshape scientists' understanding of how the ice sheet expands and moves, and how it might react to warming climate, they say. The study appears in this week's early online edition of the journal Science; it is part of a six-nation study of the invisible Gamburtsev Mountains, which lie buried under as much as two miles of ice.
Ice sheets are well known to grow from the top as snow falls and builds up annual layers over thousands of years, but scientists until recently have known little about the processes going on far below. In 2006, researchers in the current study showed that lakes of liquid water underlie widespread parts of Antarctica. In 2008-2009, they mounted an expedition using geophysical instruments to create 3-D images of the Gamburtsevs, a range larger than the European Alps. The expedition also made detailed images of the overlying ice, and subglacial water.
"We usually think of ice sheets like cakes--one layer at a time added from the top. This is like someone injected a layer of frosting at the bottom--a really thick layer," said Robin Bell, a geophysicist at Columbia University's Lamont-Doherty Earth Observatory and a project co-leader. "Water has always been known to be important to ice sheet dynamics, but mostly as a lubricant. As ice sheets change, we want to predict how they will change. Our results show that models must include water beneath."
The Antarctic ice sheet holds enough fresh water to raise ocean levels 200 feet; if even a small part of it were to melt into the ocean, it could put major coastal cities under water. The scientists found that refrozen ice makes up 24% of the ice sheet base around Dome A, a 13,800-foot-high plateau that forms the high point of the East Antarctic ice sheet, at 3.8 million square miles roughly the size of the continental United States. In places, slightly more than half the ice thickness appears to have originated from the bottom, not the top.
Posted by Amanda Graham | 3/3/11; 10:49:34 PM | Permalink
How does ice flow? First results of a new measurement method in Antarctica
(Helmholtz Association of German Research Centres press release via EurekAlert and ScienceDaily, 9 May 2010) - At the annual General Assembly of the European Geological Union in Vienna, Dr. Olaf Eisen from the German Alfred Wegener Institute is presenting results from an environmentally friendly measurement method that he and his colleagues used on an Antarctic ice shelf for the first time in early 2010. The method supplies data that are input to models for the ice mass balance and thus permit better forecasting of future changes in the sea level.
The quality of scientific models depends to a decisive degree on the available database. Therefore members of a young investigators group supported by the German Research Foundation (DFG) now applied a special geophysical measurement method, vibroseismics, for data collection in the Antarctic for the first time. "By means of vibroseismic measurements, we would like to find out more about the structure of the ice and thus about the flow characteristics of the Antarctic ice sheet," explains Dr. Olaf Eisen from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. He is head of the LIMPICS young investigators group (Linking micro-physical properties to macro features in ice sheets with geophysical techniques).
Eisen now presents first results from geophysical measurement campaign in the Antarctic on the international conference. The objective of the expedition was to determine the internal structure of an ice sheet from its surface by means of geophysical methods. The cooperation partners are the Universities of Bergen (Norway), Swansea (Wales, UK), Innsbruck (Austria) and Heidelberg (Germany) and the Commission for Glaciology of the Bavarian Academy of Sciences and Humanities. For test purposes vibroseismics was used along with proven explosive seismic methods for the first time on an ice sheet.
Posted by Amanda Graham | 5/9/10; 12:52:06 PM | Permalink
No more [large] cruise ships in Antarctica
(inewp.com, 3 April 2010) -- The International Maritime Organisation initialized a ban on using heavy fuel oil for any ship operating in the waters of Antarctica. This tough ban will most likely drive out the large cruise ships that travel to Antarctica annually but not the midsized nor small ships that already operate on lighter fuel.
Tourists or passengers on these ships which can carry up to nearly 1,900 people will have to reserve their spots on smaller “cruise” ships to tour the mysterious land of ice or at least see it close enough to get a feel for this coldest and most driest continent.
The ban’s purpose is to reduce environmental hazards such as fuel leaks or even oil spills if the ship makes contact with an object, namely an iceberg. The light fuel is much more less harmful than the heavier fuels and quickly washes away in the water which is better for the environment and its creatures. ...
According to the International Association of Antarctica Tourism Operators, the passengers for cruise ships are likely to decrease from the ten thousands to the single thousands because of this ban. The ban will not go into effect immediately but will go into effect August 2011.
Posted by Amanda Graham | 4/5/10; 11:36:58 AM | Permalink
Giant iceberg breaks off from Antarctic glacier
(Reuters, 26 February 2010) -- An iceberg the size of Luxembourg has broken off from a glacier in Antarctica after being rammed by another giant iceberg, scientists said on Friday, in an event that could affect ocean circulation patterns. The 2,500 sq km (965 sq mile) iceberg broke off earlier this month from the Mertz Glacier's 160 km (100 miles) floating tongue of ice that sticks out into the Southern Ocean. The collision has since halved the size of the tongue that drains ice from the vast East Antarctic ice sheet.
"The calving itself hasn't been directly linked to climate change but it is related to the natural processes occurring on the ice sheet," said Rob Massom, a senior scientist at the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Center in Hobart, Tasmania. Both organizations, along with French scientists, have been studying existing giant cracks in the ice tongue and monitored the bumper-car-like collision by the second iceberg, B-9B.
This 97-km-long slab of ice is a remnant of an iceberg of more than 5,000 sq km that broke off, or calved, in 1987, making it one of the largest icebergs ever recorded in Antarctica. The Mertz glacier iceberg is among the largest recorded for several years. In 2002, a iceberg about 200 km long broke off from Antarctica's Ross Ice Shelf. In 2007, a iceberg roughly the size of Singapore broke off from the Pine Island Glacier in West Antarctica. Massom said the shearing off of the ice tongue and the presence of the Mertz and B-9B icebergs could affect global ocean circulation.
Posted by Amanda Graham | 2/27/10; 1:29:41 AM | Permalink
Chile to build new airfield and ports in Antarctica
(Pakistan News.Net, 16 February 2010) -- Chile is to institute new projects on its base in the Antarctic. The projects on King George Island will include improving the quality of existing facilities, the construction of new buildings, a docking pier and port development.
The lengthening and improvement of the Teniente Marsh airfield, the main Chilean airfield on King George Island, will also be undertaken. The renovation of the airfield, which will allow mainland access to Chile’s Antarctic territory, will cost more than US$100 million.
Posted by Amanda Graham | 2/21/10; 9:31:04 PM | Permalink
Scott of the Antarctic's final diary published online
(Maev Kennedy/Guardian, 3 February 2010) -- Readers can, from today, pore over the pages of faded pencil
handwriting that make up one of the most famous diaries in the world –
Captain Robert Scott's journal of the final months, days and hours of
his doomed 1911-1912 expedition to the South Pole.
The British Library has launched an online facsimile of the complete last diary alongside extensive extracts from the two earlier volumes. The move means people can follow the setbacks that befell his group – the deterioration of the weather, illness and injury and food and fuel supplies running out – until they died in their tent on 29 March 1912, only 11 miles from a supply depot. Long before writing his last sentences – "It seems a pity, but I do not think I can write more – R. Scott – For God's sake look after our people" – the explorer knew they were finished. They had already experienced the shock of reaching the Pole only to find that the Norwegian explorer Roald Amundsen had beaten them to it. Scott described that as "a horrible day" and admitted for the first time that he and his companions might not survive the journey back. ...
Katrina Dean, the curator of the history of science at the library, said: "Scott's Antarctic diaries have played an important role in shaping images of polar exploration, so it's great that people all over the world can explore the original diaries online." Two of the original diaries are on view in the library's treasures gallery at King's Cross, London.
Posted by Amanda Graham | 2/6/10; 10:35:05 PM | Permalink
Explorers' century-old whisky found in Antarctic
(CBC News, 5 February 2101) -- This Scotch has been on the rocks for a century. Five crates of Scotch whisky and two of brandy have been recovered by a team restoring an Antarctic hut used more than 100 years ago by famed polar explorer Ernest Shackleton. Ice cracked some of the bottles that had been left there in 1909, but the restorers said Friday they are confident the five crates contain intact bottles "given liquid can be heard when the crates are moved."
New Zealand Antarctic Heritage Trust team leader Al Fastier said the team thought there were two crates and were amazed to find five. Current distillery owner, drinks group Whyte & Mackay, launched the bid to recover the Scotch whisky for samples to test and decide whether to relaunch the defunct spirit made by distiller McKinlay and Co. Fastier said restoration workers found the crates under the hut's floorboards in 2006, but they were too deeply embedded in ice to be dislodged. The New Zealanders agreed to drill the ice to try to retrieve some bottles, although the rest must stay under conservation guidelines agreed to by twelve Antarctic Treaty nations.
"The unexpected find of the brandy crates, one labelled Chas. Mackinlay & Co and the other labelled The Hunter Valley Distillery Limited Allandale (Australia), are a real bonus," said Fastier. ... Richard Paterson, master blender at Whyte and Mackay, whose company supplied the Mackinlay's whisky for Shackleton, described the find as "a gift from the heavens for whisky lovers. "If the contents can be confirmed, safely extracted and analyzed, the original blend may be able to be replicated. Given the original recipe no longer exists, this may open a door into history," he said in a statement.
Posted by Amanda Graham | 2/5/10; 7:01:12 PM | Permalink
N.L. child's penguin drawing goes viral
(CBC News, 30 January 2010) -- A pencil sketch that was created last fall as a joke between an autistic child from Newfoundland and his mother over her kicking his toy penguin has turned into a web phenomenon, resulting in hundreds of dollars in novelty sales involving the drawing.
Seven-year-old Colby Chipman made the drawing back in October after he saw his mother Michelle kick the toy out of her way as she walked through their home in Paradise, just outside of St. John's. "He said, 'Mommy, there's no kicking penguins!' she told CBC News. Chipman said her son then raced into his room and emerged a few minutes later with a sheet of yellow paper that had a stick drawing of a person in a kicking motion standing near a penguin. There was a circle around the sketch and a diagonal line through it — the global sign for something that isn't permitted.
"He came back, taped it to the wall and said 'See Mommy, there's no kicking penguins,'" Chipman said. ... Chipman said the drawing went viral after it appeared on reddit.com, a social news website on which users can post links to content on the internet and make comments. "A British researcher in Antarctica thought it was cool, printed it off and then started taking pictures of it near penguins and the ocean, and it's just gone global from there," she said.
Posted by Amanda Graham | 1/30/10; 11:58:39 PM | Permalink
