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TOPIC: Antarctica


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RE: Antarctica
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Unlike the Arctic regions, Antarctica is a continent surrounded by oceans. This ecological difference causes its internal regions to miss the benefits of temperature regulation of surrounding waters. Almost 98 per cent of the continents area is covered with ice and snow, causing large amounts of light radiation to be reflected back into the environment, keeping the temperatures cold and dreadful.
Due to the harsh cold weather and extreme dryness of the air, observations of Antarctica have only been a focus for a century, which is a considerably short period of time when compared with the other continents around the world. The technological developments in the last five decades have aided in learning the characteristics of cloud formations, distributions and other environmental patterns in Antarctica.

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Live Earth concert
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What must surely be the coolest gig in this summers Live Earth concerts takes place at the British Antarctic Surveys (BAS) Rothera Research Station. On 7 July the science teams indie-rock house band, Nunatak* will debut in the global event that features over 100 of the worlds top musical acts. Concerts from all 7 continents will raise awareness of climate change world-wide.
Darkness and freezing temperatures isolate the Antarctic continent during the Southern Hemisphere winter so the only people who can actually go to the Antarctic concert will be Nunataks 17 over-wintering colleagues. But an astounding 2 billion people worldwide will get to enjoy the 5-piece combo through broadcasts on TV, film, radio and the internet.

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RE: Antarctica
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KML collection [GE File. You must have Google Earth/Worldwind installed.] of placemarks for more than 120 Antarctic research stations and bases. - Past and present. (1kb)

Open all layers in GoogleEarth: PolarView Antarctic node (5kb, kml)

Polar view
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 A team of NASA and university scientists has found clear evidence that extensive areas of snow melted in west Antarctica in January 2005 in response to warm temperatures. This was the first widespread Antarctic melting ever detected with NASA's QuikScat satellite and the most significant melt observed using satellites during the past three decades. Combined, the affected regions encompassed an area as big as California.
Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, California, and Konrad Steffen, director of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder, led the team. Using data from QuikScat, they measured snowfall accumulation and melt in Antarctica and Greenland from July 1999 through July 2005.



The observed melting occurred in multiple distinct regions, including far inland, at high latitudes and at high elevations, where melt had been considered unlikely. Evidence of melting was found up to 900 kilometres  inland from the open ocean, farther than 85 degrees south (about 500 kilometres  from the South Pole) and higher than 2,000 metres  above sea level. Maximum air temperatures at the time of the melting were unusually high, reaching more than five degrees Celsius (41 degrees Fahrenheit) in one of the affected areas. They remained above melting for approximately a week.

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Ice covers much of East Antarctica. Draining from the East Antarctic Ice Sheet is a river of ice nearly 800 kilometres long. This stream, the Recovery Ice Stream, slides roughly 35 billion tons of ice into the weddell sea each year. In order to understand how large ice caps like the ones on Antarctica and Greenland will react to global warming, scientists must understand the basic dynamics of ice sheets, things like how fast they move, what causes them to speed up and slow down, and how much ice they carry to the ocean. In 2007, scientists reported that several large lakes lie beneath the Recovery Ice Stream and that when the ice stream flow over them, it speeds up.

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Credit: NASA

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West Lake Bonney
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A robotic probe designed to draw an underwater three-dimensional map showing the biological and geochemical composition of an ice-bound Antarctica lake may prove to be the ideal tool to search for life on other planets or moons where ice is known to exist.
Peter Doran, associate professor of earth and environmental sciences at the University of Illinois at Chicago, is the lead investigator in a three-year, $2.3 million dollar study funded by NASA to build the probe that will map Antarctica's West Lake Bonney, a two-and-a-half mile long, one-mile wide, 130 foot-deep lake located in the continent's McMurdo Dry Valleys. Bonney lies perpetually trapped beneath 12 to 15 feet of ice.

"Our goal is to build a submersible autonomous underwater vehicle to map in 3-D the geochemistry and biology of this ice-covered lake" - Peter Doran, who is also a principal investigator on the National Science Foundation's Long-Term Ecological Research project in the McMurdo Dry Valleys.

NASA is interested in the project because a modified version of the vehicle may be used to probe beneath subglacial ice and look for signs of life, past or present, on Mars or on moons such as Jupiter's Europa, which essentially is an ice-covered ocean.

"The robot will swim under the ice un-tethered.  It will have a sensor package that will lower down on a cable as it moves under the ice. It will do a grid pattern, stop, and lower the sensor package down through the whole water column to build up a 3-D data set. It will also have a camera to take various images" - Peter Doran.

The probe is called ENDURANCE -- an acronym for Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer. It is a modified version of a device called DEPTHX -- Deep Phreatic Thermal Explorer -- developed by Austin, Texas inventor William Stone, a co-investigator on the ENDURANCE project. Stone is using DEPTHX to explore underwater caves in Mexico as part of NASA's Astrobiology, Science and Technology for Exploring Planets program. Once that is complete, DEPTHX will be reengineered to become ENDURANCE, then tested next February in an ice-covered Wisconsin lake before making the trip to Antarctica in November. ENDURANCE will map Bonney for a month, then do a second mapping in 2009. Data gathered will be relayed back to Chicago where it will be used by UIC's Electronic Visualisation Laboratory to generate various 3-D images, maps and data renderings of the lake.

"The potential scientific windfall is huge. We'll see lakes like we've never seen them before" - Peter Doran.

ENDURANCE is about four feet tall and three feet wide. It will be decontaminated and sterilized before being lowered through the ice hole into the lake. Because it will gently float around the top water layer and will slowly lower its sensor package into older, denser layers of water below, there is little chance of the water churning and mixing, which could skew the biological and geochemical picture of the lake.
If the autonomous vehicle works well, the next goal is sending a much smaller version of ENDURANCE to probe Antarctica's massive, Lake Ontario-sized Lake Vostok, which sits under more than two-and-a-half miles of ice. Some water in Vostok hasn't had contact with the earth's atmosphere in over a million years.

"The lessons learned from mapping out Bonney will be important for developing strategies for exploring Vostok and icy moons, like Europa. You're not going to send people there, so you have to develop autonomous ways to do it" - Peter Doran.

Other project co-investigators include Andrew Johnson, associate professor of computer science at UIC; John Priscu, professor of land management and environmental sciences at Montana State University; and Chris McKay and Bin Chin at the NASA Ames Research Centre in California.

Source: University of Illinois at Chicago

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Antarctica's warmer past
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Tiny they may be, but fossil diatoms discovered deep under the ocean floor are revealing new details about Antarctica's warmer past.
The single-celled algae were pulled up by the Antarctic Geological Drilling (Andrill) Program, which has been operating from the Ross Ice Shelf.
Some are new to science; others would normally only be expected in waters with higher temperatures than today.
Scientists say the diatoms will help them understand future climate changes.

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Lyall Bay
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A Kiwi-led Antarctic drilling expedition has unearthed unexpected history of the icy continent - which may have once hosted surf beaches the envy of Lyall Bay.
Frequent climate shifts in Antarctica have been so extreme in the past five million years that Antarctica's Ross Ice Shelf routinely melted away, exposing long stretches of coastline ripe for surfing.
Researchers with the Antarctic Geological Drilling Program have begun analysing a 1285-metre sediment core, which was extracted from beneath Ross Ice Shelf in January.
The core, at Northern Illinois University in the United States, is providing a trove of information .

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Byrd Glacier
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This image shows the Byrd Glacier flowing through a deep, 15-mile-wide valley in the Transatlantic Mountains, as it flows towards the Ross Ice Shelf at a rate of one half mile per year.
The Byrd Glacier is located near the Antarctic Research Base, McMurdo Station. glacier

byrdglacier_sm
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Credit NASA

byrdglacier_lg
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Credit NASA

This image of part of the Byrd Glacier was captured by the Landsat 7 satellite on December 24, 1999.

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Posts: 131433
Date:
Antarctica
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Current Events off Antarctica
Graduate student helps discover a previously unknown ocean current
The scientific method can divert researchers down curious pathways. Human psychologists study mouse brains. Astrophysicists look for cosmic particles deep in mine shafts. Taxonomists trace bird evolution by studying feather lice.
Carlos Moffat’s scientific career took a similar detour. Fascinated by marine biology, he became a physical oceanographer to understand the ways ocean water moves, mixes, and nourishes life at the bottom of the marine food chain.

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