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Posts Tagged ‘antarctica’

Endurance Uncovered

Tuesday, May 10th, 2022
The Endurance shipwreck photographed at the bottom of the Weddell Sea, east of the Antarctic Peninsula. The photo shows the stern (back) of the ship. Credit: © Falklands Maritime Heritage Trust/National Geographic

The Endurance shipwreck was photographed at the bottom of the Weddell Sea, east of the Antarctic Peninsula. The photo shows the stern (back) of the ship.
Credit: © Falklands Maritime Heritage Trust/National Geographic

In a testament to its name, the legendary Endurance is in one piece after sinking off the coast of Antarctica 107 years ago. On March 5, 2022, a search expedition organized by the Falklands Maritime Heritage Trust discovered the shipwreck of the Endurance. It was at the bottom of the Weddell Sea, east of the Antarctic Peninsula in the Southern Ocean, about 4 miles (6 kilometers) from its last position as recorded by its captain. The ship’s hull (body) was largely intact. Under the international Antarctic Treaty, the ship was protected as a historic site and monument and left undisturbed.

The expedition which took off at the beginning of World War I (1914-1918) was led by Sir Ernest Henry Shackleton. Shackleton was a British explorer who made four journeys to Antarctica. In 1909, he came within 97 nautical miles (about 110 miles or 180 kilometers) of the south geographic pole, sometimes called simply the South Pole. Shackleton measured in nautical miles, because he wanted to reach a point within 100 miles of the pole. It was the farthest point south any expedition had reached. Shackleton also is known for a heroic rescue mission that he undertook in 1915-1916.

Shackleton was born on Feb. 15, 1874, in Kilkea, County Kildare, Ireland, then part of the United Kingdom. His family moved to London, England, when he was a child. Shackleton was educated at Dulwich College in London. He joined the British merchant marine when he was 16 years old and served for about 10 years.

From 1901 to 1903, Shackleton served on an Antarctic expedition led by the British explorer Robert Falcon Scott. Shackleton was part of a small party that trekked across the Ross Ice Shelf. The group reached a point about 530 miles (850 kilometers) from the south geographic pole. It was the farthest south that anyone had gone. After returning to the United Kingdom, Shackleton worked as a journalist and as secretary of the Royal Scottish Geographical Society while raising funds for his own expedition. In 1906, he ran unsuccessfully for Parliament.

From 1907 to 1909, Shackleton led his British Antarctic Expedition. Shackleton and three of his men traveled overland from Ross Island toward the south geographic pole. On Jan. 9, 1909, they reached a latitude of 88 degrees 23 minutes, more than 400 miles (600 kilometers) closer to the pole than Scott’s expedition had gotten. Another small party traveled north from Ross Island and came close to reaching the south magnetic pole. Members of the expedition also made the first ascent of Mount Erebus, on Ross Island, in 1908, as well as the first motion pictures of Antarctica. Shackleton returned to England a hero and was knighted.

Shackleton’s Imperial Trans-Antarctic Expedition of 1914-1917 did not accomplish its goal of crossing the continent from the Weddell Sea to the Ross Sea. However, it became one of history’s great stories of survival. Shackleton’s ship, the Endurance, became trapped in ice in the Weddell Sea near the coast of Antarctica in January 1915. It drifted north for about 10 months before it finally was crushed by the ice and sank on Nov. 21, 1915. The crew had abandoned the ship in late October, and they camped on floating ice for several months. In April 1916, they traveled in small boats to desolate Elephant Island, off the tip of the Antarctic Peninsula. Leaving 22 men on Elephant Island, Shackleton and five companions then made a daring open-boat journey of 800 miles (1,300 kilometers). They sailed northeast and reached the island of South Georgia in 17 days. Shackleton and two men trekked across the island’s snowy mountains for 36 hours to get help at a whaling station. It took until August 1916 to reach the 22 men stranded on Elephant Island, but the entire expedition of 28 men was rescued.

Shackleton served with British forces in Russia near the end of World War I. He set out once more for Antarctica in September 1921. However, he died of a heart attack on his ship in Grytviken Harbour, South Georgia, on Jan. 5, 1922. Shackleton wrote about his adventures in the books The Heart of the Antarctic (1909) and South (1919).

Tags: antarctica, endurance, expedition, shipwreck, sir ernest henry shackleton, south pole
Posted in Current Events, History | Comments Off

Antarctica with a Side of SALSA

Wednesday, October 9th, 2019

October 9, 2019

Antarctica is the coldest, highest, brightest, driest, and windiest continent on Earth. It also the least explored, and there is little knowledge of what lies beneath Antarctica’s many glaciers. In late 2018 and early 2019, however, the Subglacial Antarctic Lakes Scientific Access (SALSA) project began digging beneath the ice, hoping to learn more about the biome (collection of living things) in West Antarctica’s subglacial Mercer Lake.

This photograph shows the edge of a glacier in Antarctica. The continent is covered by huge, thick glaciers called ice sheets. Credit: © Roger Mear, Stone/Getty Images

Antarctica is covered by huge, thick glaciers called ice sheets. Scientists are beginning to learn more about life beneath the ice. Credit: © Roger Mear, Stone/Getty Images

Ice and snow cover 98 percent of Antarctica. High mountain peaks and a few other bare rocky areas make up the only visible land. Underneath the ice lie features similar to those on other continents, including mountains, lowlands, valleys, and even lakes and rivers. Mercer Lake lies beneath a massive ice sheet near the South Pole. Global warming is reducing Mercer Lake’s protective ice layer, however, and the unique subglacial habitat may soon change or even cease to exist.

The United States Antarctic Integrated System Science Program and the National Science Foundation’s Office of Polar Programs created SALSA to study Antarctica’s subglacial environment. In December 2018 and January 2019, a SALSA team of 50 scientists, drillers, and support staff was deployed to the area above Mercer Lake. Using a high-pressure, hot-water drill, the team probed 4,000 feet (1.2 kilometers) into the ice. The team used a device called a corer to raise water, ice, and sediment from the lake and filter pumps to trap small particles. Sediment samples contained the ancient remains of bacteria, crustaceans, water bears (tardigrades), diatoms (microscopic algae), plants, and fungi. Radiocarbon dating will eventually establish the age of these remains, but they are most likely millions of years old. DNA sequencing will determine if the crustaceans belonged to marine or freshwater species.

Click to view larger image Antarctica. Credit: WORLD BOOK map

Click to view larger image. Antarctica.
Credit: WORLD BOOK map

SALSA scientists explained that the ancient organisms reached cold, dark, and isolated Mercer Lake through the transfer of water beneath Antarctica’s ice sheets. Mercer and other lakes there gain and lose water on a regular basis (over decades or centuries). Organisms in the water are passed among subglacial lakes and streams and from nearby ocean bays. Antarctica has more than 300 subglacial lakes, and nearly half of those lakes periodically drain and fill.

Subglacial lakes are extremely salty, permanently dark environments with water temperatures below the normal freezing point of water. Studying the evolution of life in such extreme environments on Earth helps inform our understanding of the possibility of life on Mars and other celestial bodies. If life exists on Mars, it could likely be found in such subglacial lakes.

Tags: antarctica, mercer lake, south pole, Subglacial Antarctic Lakes Scientific Access
Posted in Current Events, Environment, People, Science | Comments Off

New Zealand’s Monster Penguin

Monday, August 26th, 2019

August 26, 2019

In New Zealand, a newly identified species of ancient giant penguin—or “monster” penguin as dubbed by the Canterbury Museum in Christchurch—has added to the southwest Pacific island nation’s roster of extinct oversized animals. The leg and foot bones of Crossvallia waiparensis, a 5-foot, 3-inch (1.6-meter) tall, 180-pound (80-kilogram) penguin, were found in Waipara, North Canterbury, on New Zealand’s South Island.

An illustration shows the approximate height of a giant penguin next to a woman. Credit: © Canterbury Museum

This illustration shows the ancient giant penguin Crossvallia waiparensis alongside a modern human. Credit: © Canterbury Museum

The ancient “monster” penguin bones were discovered in 2018 at Waipara Greensand, a geological formation that has produced significant penguin fossils before. Researchers from the nearby Canterbury Museum and the Senckenberg Natural History Museum in Frankfurt, Germany, studied the penguin fossils, and they named C. waiparensis as a new species in the Aug. 12, 2019, issue of Alcheringa: An Australasian Journal of Palaeontology.

C. waiparensis, which lived during the Paleocene Epoch between 66 million and 56 million years ago, was roughly four times larger than the emperor penguin, the largest of all modern penguins. During the time of C. waiparensis, New Zealand was still attached to Australia, which was once connected to Antarctica. A related prehistoric giant penguin, Crossvallia unienwillia, was discovered in Antarctica’s Cross Valley in 2000. The leg bones of both giant penguins suggest their feet were more adapted for swimming than those of modern penguins, and they may not have stood upright as modern penguins do.

Scientists have discovered that penguins, such as these Emperor penguins, have lost the ability to taste certain types of foods. (Credit: © Shutterstock)

Emperor penguins, seen here in Antarctica, are the largest living penguins. They stand about 3 feet (1 meter) tall and weigh as much as 100 pounds (45 kilograms). (Credit: © Shutterstock)

Prior to the discovery of C. waiparensis, New Zealand’s legacy of ancient giant critters already included the world’s largest parrot (Heracles inexpectatus), a massive eagle (Hieraaetus moorei), a dog-sized burrowing bat (Vulcanops jennyworthyae), the more than 6-foot (2-meter) tall moa, and other giant penguins.

Tags: animals, antarctica, birds, Crossvallia waiparensis, extinction, new zealand, paleontology, penguins, south island
Posted in Animals, Conservation, Current Events, History, Prehistoric Animals & Plants, Science | Comments Off

Ice Memory: A Glacier Archive

Wednesday, July 12th, 2017

July 12, 2017

Last month, in June, an international team of researchers and scientists braved heavy snows, freezing winds, and thin air to extract ice core samples from the Illimani glacier high in the Andes Mountains of Bolivia. The samples were the latest collected by teams from Ice Memory, a project aiming to gather ice samples from endangered glaciers around the world. The archive—which will be stored in a sanctuary in Antarctica—will allow future studies of glaciers that will soon fall victim to global warming. Ice Memory is managed by the University of Grenoble Alps Foundation in France and supported by the French and Italian national commissions for the United Nations Educational, Scientific and Cultural Organization (UNESCO).

Scientists who are drilling at the summit camp. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

On June 6, 2017, the Ice Memory team drills near their camp on the Illimani glacier in the Andes Mountains of Bolivia. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

At 21,004 feet (6,402 meters), Illimani is the highest mountain in the Cordillera Real range of western Bolivia. Glaciers on Illimani have existed for many thousands of years, but they are rapidly melting and retreating as climate change increases Earth’s temperatures. Glacier ice reads like a historical record of climate and environment, preserving ancient animal, plant, and mineral samples as well as showing glacial growth over millennia. They also show variations in temperatures and more recent concentrations of greenhouse gases and other pollutants. Saving Illimani cores will allow scientists to study the ice long after the host glaciers have disappeared.

Scientists who are extracting an ice core. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

Scientists remove ice from the drilling core on the Illimani glacier in Bolivia on June 9, 2017. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

It took several weeks for the Illimani team to drill through the ice and extract the core samples, both of which were more than 440 feet (135 meters) long. Dangerous weather forced the team to abandon the planned retrieval of a third sample. The glacier cores were then cut into smaller pieces, stored in tubes, and catalogued. The samples will eventually make their way to the archive at Concordia Station in Antarctica, where they will join the first core samples extracted from France’s Mont Blanc in 2016. The Concordia glacier archive is meant to store hundreds of ice core samples in a protected snow cave at -65° Fahrenheit (-54° Celsius).

The ice cores and their tubes putting together in the snow cave. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

An Ice Memory researcher stacks tubed sections of ice core in an improvised snow cave on the Illimani glacier on June 5, 2017. The samples will eventually be stored in Antarctica. Credit: © Sarah Del Ben, Wiltouch/Fondation UGA

Future core extractions are planned for such threatened glacier areas as Mera Peak in Nepal, Mount Elbrus in Russia, Mount Kilimanjaro in Tanzania, and sites in the Swiss Alps and the Altai Mountains in Asia. Ideally, three glacier samples from each area will provide one sample for immediate analysis and two for storage and archiving. Aside from providing clues about the past, the samples help scientists understand the current effects of climate change and predict future environmental events.

Tags: andes mountains, antarctica, bolivia, climate change, glacier archive, glaciers, global warming, illimani
Posted in Conservation, Current Events, Environment, History, People, Plants, Science | Comments Off

Ailing Antarctica

Thursday, June 22nd, 2017

June 22, 2017

In May 2017, scientists watched anxiously as an enormous crack in Larsen C, one of Antarctica’s largest ice shelves, grew by more than 11 miles (18 kilometers) in just a few days. Scientists have been closely monitoring the Larsen C ice shelf, where a large fissure in the ice has been advancing and widening in rapid bursts in recent years. When it eventually breaks away, it will form one of the largest icebergs ever seen.

Snapshot of the rift in the Larsen C on Nov. 10, 2016. Credit: NASA/John Sonntag

An airplane passes above the giant crack in Antarctica’s Larsen Ice Shelf in late 2016. Credit: NASA/John Sonntag

The Larsen Ice Shelf is a broad, flat, floating mass of ice in the northwest part of the Weddell Sea. It extends along the east end of the Antarctic Peninsula. Researchers who work in the area originally labeled three segments of the massive ice shelf as Larsen A, Larsen B, and Larsen C (running north to south). The Larsen A ice shelf broke away and disintegrated in 1995. The Larsen B ice shelf disintegrated in 2002. Researchers fear the disintegration of Larsen C, the largest of the three and the fourth largest in Antarctica, will leave the continent’s whole system vulnerable to future break-up.

An image of the rift in the Larsen C on Nov. 10, 2016 from the Digital Mapping System. Credit: NASA Goddard Space Flight Center

This airborne photograph shows a detail of the massive 300-foot- (100-meter-) wide rift in Larsen C in late 2016. Credit: NASA Goddard Space Flight Center

Larsen C is substantially larger than its former neighbors Larsen A and B, and its loss would be a huge blow to ice on the Antarctic Peninsula. When the shelf breaks away as an iceberg, it will weaken or destroy key areas where ice overlaps nearby islands. The ice shelf helps keep larger ice masses nearby from falling apart. Losing Larsen C would destabilize and even threaten the existence of the area’s larger ice masses.

Click to view larger image The current location of the rift on Larsen C, as of May 31 2017.  Labels highlight significant jumps. Tip positions are derived from Landsat (USGS) and Sentinel-1 InSAR (ESA) data. Background image blends BEDMAP2 Elevation (BAS) with MODIS MOA2009 Image mosaic (NSIDC). Other data from SCAR ADD and OSM.  Credit: © A. Luckman, MIDAS project/Swansea University

Click to view larger image
This map shows the rift on Larsen C on May 31, 2017, and its growth since 2010. The shelf is larger than Wales in the United Kingdom. Credit: © A. Luckman, MIDAS project/Swansea University

Antarctica has about 90 percent of the world’s ice with a volume of about 7.25 million cubic miles (30 million cubic kilometers). The average thickness of the ice is over 7,100 feet (2,200 meters), and the masses contain about 70 percent of the world’s fresh water. Most of this ice lies in two massive sheets that can be as thick as 11,500 feet (3,500 meters). If all that ice melted, Earth’s oceans would rise nearly 230 feet (70 meters), flooding coastal cities around the world.

Antarctica's Larsen B Ice Shelf is likely to shatter into hundreds of icebergs before the end of the decade, according to a new NASA study. Credit: Ted Scambos, NSIDC

Antarctica’s Larsen B Ice Shelf broke apart in 2002, forming these icebergs that have since melted and disappeared. Credit: Ted Scambos, NSIDC

Scientists blame the disintegration of the Larsen Ice Shelf on global warming. The ice destruction has destabilized the entire eastern Antarctic Peninsula and raised sea levels. Scientists note that global warming does not affect all parts of the world equally. Average temperatures in Antarctica have jumped 5 Fahrenheit degrees (2.8 Celsius degrees) since the 1950′s, a faster rate of increase compared to other parts of the Earth. Climate scientists think that temperatures could increase up to 7 Fahrenheit degrees (3.9 Celsius degrees) further in the coming decades, putting ever more stress on the ice.

Ice shelves themselves do not contribute directly to sea level rise because they are floating on the ocean and they already displace the same volume of water. But scientists are still deeply troubled by the collapse of Larsen C. In Antarctica, ice shelves act as doorstops to the land-based glaciers that feed them. As ice shelves disappear, the glaciers move faster and flatten out, pushing ever more ice into the ocean and raising sea levels.

Although cycles of cooling and warming as well as other natural processes affect Antarctica’s climate, scientists are largely in agreement that human activities, particularly emissions of heat-trapping greenhouse gases, are the main driving force behind the area’s temperature increases and the resulting loss of the ice shelves. The most significant greenhouse gas is carbon dioxide, which is produced by the burning of such fossil fuels as coal and oil. A number of other atmospheric, oceanic, and glaciological factors are also involved.

Tags: antarctica, climate change, global warming, ice shelves
Posted in Conservation, Current Events, Environment, People, Science | Comments Off

Don Juan’s Salty Waters

Friday, August 19th, 2016

August 19, 2016

In Victoria Land on the Antarctic coast, there lies a small body of water so salty that it is almost impossible to freeze—even in the coldest place on Earth! Don Juan Pond, which lies in the cold continent’s Wright Valley near the Ross Sea, is so salty that temperatures must plummet to -127 °F (-53 °C) to freeze it—far colder than the area’s average temperature and far colder still than the 32 °F (0 °C) needed to freeze pure water. (Salt lowers the melting point of ice, which is why it is spread on icy roads and walks in winter). The small pond—it covers roughly 7½ acres (3 hectares) with an average depth of just 4 inches (10 centimeters)—is 44 percent saline, making it the saltiest natural body of water on Earth. By comparison, the famous Dead Sea in southwestern Asia is about 33 percent saline, and the second saltiest body of water, Lake Vanda (a larger, deeper neighbor of Don Juan), is 35 percent saline.

The extreme landscape around Antarctica's Don Juan Pond (the black pool in the right of the photograph) resembles a lunar or Martian scene more than a glimpse of our own planet Earth. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio/Landsat 7 Project Science Office/MODIS Rapid Response Team

The extreme landscape around Antarctica’s Don Juan Pond (the black pool in the right of the photograph) resembles a lunar or Martian scene more than a glimpse of our own planet Earth. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio/Landsat 7 Project Science Office/MODIS Rapid Response Team

Don Juan Pond was not named after the Spanish legendary figure, but rather for the United States Navy helicopter pilots who discovered it: Lieutenants Donald Roe and John Hickey—Don Juan (John). The Navy pilots first saw the pond on Oct. 11, 1961, during a reconnaissance flight through the McMurdo Dry Valleys—an area called “dry” because it is free of snow and ice, a rare thing in Antarctica. Glaciers carved the valleys long ago, and snow that falls there is swept away by winds. The valleys have only trace amounts of snow or ice melt or groundwater. Consequently, researchers believe that the brine of Don Juan Pond comes from salt deliquescence, a process by which the salt melts or becomes liquid by absorbing moisture from the air.

On that cold October day in 1961, the pond was liquid despite the −22 °F (−30 °C) temperature. Continued studies by the U.S. Antarctic Program found a new mineral at the pond, calcium chloride hexahydrate (sometimes called Antarcticite), as well as vast amounts of sodium chloride (ordinary table salt). Remarkably, researchers also identified species of algae, fungi, and heterotrophic (parasitic) bacteria living in the harsh brine of Don Juan Pond. Later studies found the pond (which varies in size but has shrunk considerably since the 1960′s) devoid of such extremophile life, but high levels of nitrous oxide around the lake may indicate continued microbial activity. Regardless, the possibility of life in Don Juan Pond—as well as the pond’s very existence—fuels speculation for the existence of water and life in another extreme environment, the surface of our planetary neighbor Mars.

Tags: antarctica, don juan pond, salt water
Posted in Animals, Current Events, Environment, Science | Comments Off

Antarctic Trek Ends Tragically

Tuesday, January 26th, 2016

January 26, 2016

British explorer Henry Worsley’s attempt to be the first person to walk across Antarctica unaided ended tragically with his death this past Sunday, January 24. Worsley was forced to end his trek just 30 miles (50 kilometers) short of his goal because of dehydration and exhaustion. Since the start of his journey on Nov. 13, 2015, on Berkner Island, Antarctica, Worsley had walked alone across the continent, battling extreme weather conditions without outside support, for 71 days. He covered 913 miles (1520 kilometers) before he could no longer continue. He requested help near the edge of the Ross Ice Shelf (see bottom section of map below). A rescue team flew Worsley to a hospital in Punta Arenas, Chile, where he died.

Antarctica (World Book map; map data © MapQuest.com, Inc.)

Worsley’s attempt to cross the frozen expanse of Antarctica recalls the gallant, yet ill-fated expeditions of British explorers Robert Falcon Scott and Sir Ernest Henry Shackleton. These expeditions took place in the first two decades of the 1900′s, a period often called the “Heroic Era” of Antarctic exploration, when explorers first reached the South Pole. In 1911, two groups of explorers raced across Antarctica to be the first to reach the South Pole. One group was led by Norwegian explorer Roald Amundsen, and the other by Robert Falcon Scott. Amundsen reached the pole on Dec. 14, 1911, about five weeks before Scott. Scott and the four other members of his group reached the pole, but they all died on the return trip. A search party found their frozen bodies inside their tent eight months later.

Sir Ernest Shackleton Credit: Library of Congress.

Sir Ernest Shackleton Credit: Library of Congress.

In 1914, Shackleton led an expedition into the Weddell Sea, where ice crushed his ship, the  Endurance. His party escaped in boats to Elephant Island. Shackleton and five companions then made a daring journey by boat to South Georgia Island and crossed the island’s glacier-covered mountainous ridge to summon rescuers. As a result, his entire party was saved.

The Irish-born British explorer Sir Ernest Henry Shackleton began an expedition to Antarctica in 1914 aboard the ship Endurance. This photograph shows the ship in full sail. It later was trapped and crushed by sea ice. © Royal Geographical Society/Alamy Images

Henry Worsley, a distant relative of Frank Worsley, a member of the Shackleton expedition, was trying to complete the mission Shackleton had started more than a century ago. Worsley’s trek across Antarctica was done to raise money for the Endeavour Fund, a charity that provides assistance to wounded British veterans through sporting and adventure challenges. Worsley raised more than 100,000 pounds (143,000 U.S. dollars) before starting his trek. The Endeavour Fund is managed by the Royal Foundation of the Duke and Duchess of Cambridge and Prince Harry of the United Kingdom.

Other World Book articles

  • Antarctica: The Hidden Continent (a Special report)
  • Exploration

 

Tags: antarctica, exploration, henry worsley
Posted in Current Events, People | Comments Off

More Bad News from Antarctica

Wednesday, December 3rd, 2014

December 3, 2014

The latest study of the West Antarctic Ice Sheet has provided more strong evidence of the devastating effect of global warming on this vulnerable region of Antarctica. The 21-year study found that the melting rate of the ice in the already-unstable Amundsen Sea region has tripled from 2003 to 2009. The findings, reported by scientists at the University of California, Irvine (UCI), and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, are being described as the most authoritative estimate of ice loss in the region.

A number of studies have revealed that the West Antarctic Ice Sheet, which contains Antarctica’s fastest flowing ice, is warming much faster than scientists had estimated and that melting there has accelerated significantly since the early 1990′s. In May 2014, scientists from UCI and JPL reported that glaciers around the Amundsen Sea, the weakest of the continent’s ice sheets, appear to have begun a gradual but “unstoppable” slide into the sea. For the new study, the UCI and JPL scientists compared measurements of the “mass balance” of glaciers flowing into the sea using four different tools, including Earth-orbiting satellites, radars, and lasers. NASA defines mass balance as a measure of how much ice the glaciers gain and lose over time from accumulating or melting snow, discharges of ice as icebergs, and other causes. The scientists found that from 1992 to 2003, the melting rate increased by 6.7 billion tons (6 billion metric tons) of ice each year. From 2003 to 2009, however, the melting rate soared to 18 billion tons (16 billion metric tons) annually. The scientists calculated that the region has shed an amount of ice equal to Mount Everest, the highest mountain in the world, every two years for the past 21 years.

The glaciers in Amundsen Sea region of West Antarctica are losing ice faster than any other glaciers on the continent. (NASA/Michael Studinger)

The West Antarctic Ice Sheet is especially vulnerable to climate change, in part, because most of the ice sheet lies on terrain that is an average of 3,300 feet (1,000 meters) below sea level. As a result, the leading edges, or tongues, of the glaciers float on seawater. When a glacier melts, its grounding line–the point where a glacier attaches to underlying terrain and begins to float–also retreats. Nearly all the melting takes place on the underside of a glacier beyond the grounding line, where the ice comes into contact with warm seawater.

Additional World Book articles:

  • Exploration (the Exploration of Antarctica)
  • Global warming (2009) (a Back in Time article)
  • The Great Meltdown (a special report)
  • Science in Antarctica (a special report)

Tags: amundsen sea, antarctica, glacier, global warming, west antarctic ice sheet
Posted in Current Events, Environment, Government & Politics, Science, Technology | Comments Off

First Sauropod Dinosaur Fossil Discovered in Antarctica

Tuesday, December 27th, 2011

Dec. 27, 2011

The discovery of the first sauropod fossil ever found in Antarctica has been announced by a team of scientists from Argentina. Sauropods, a common kind of planet-eating dinosaur, hold the record as the largest land animals to inhabit Earth. The fossil, which has been dated to about 70 million years old, is only a single vertebra–too small for scientists to determine the exact species. (Vertebrae are the bones that make up the spine.) But the scientists determined that the bone belonged to a sauropod. Scientists have found only a few dinosaur fossils in Antarctica because of the continent’s harsh conditions making searching difficult, though they believe many kinds of dinosaurs lived there.

Some sauropods may have grown as long as 130 feet (40 meters) and weighed as much as 85 tons (77 metric tons). They are among the most familiar dinosaurs, with long necks and tails. There were many kinds of sauropods, including such well-known species as Brachiosaurus and Apatosaurus. Sauropods fossils had previously been discovered on all other continents.

Supersaurus was one of the largest dinosaurs that ever lived. It measured from 100 to 130 feet (30 to 40 meters) long, stood about 27 feet (8.2 meters) tall at the hips, and may have weighed more than 40 tons (36 metric tons). The animal's slender neck may have stretched as long as 40 feet (12 meters). Its huge, whiplike tail probably extended about 50 feet (15 meters). World Book illustration by John Francis, Bernard Thornton Artists

The newly discovered dinosaur lived during the Cretaceous Period, which lasted from about 145 million to 65 million years ago. During this time, Antarctica was not covered by a thick ice sheet, as it is now. Earth’s climate was much warmer in the Cretaceous Period than it is today. As a result, Antarctica was able to support plant life, which provided food for large dinosaurs. Also, Antarctica was still connected to what are now Australia and South America in a supercontinent called Pangaea. The fossil was discovered on Ross Island, in West Antarctica.

Additional World Book articles:

  • Diplodocus
  • Plants (Early plants)
  • Prehistoric animal
  • Seismosaurus
  • Supersaurus

 

Tags: antarctica, cretaceous period, dinosaur, fossils, sauropod
Posted in Animals, Current Events, Science | Comments Off

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