Antarctic meltdown? (Earth News).LAST MARCH, a Rhode Island-size ice chunk sheared sheared adj. Shaped or finished by shearing, especially cut or trimmed to a uniform length: a sheared fur coat. Adj. 1. off the northern portion of the Larsen B Ice Shelf, a massive plate of floating ice lining the eastern coast of the arm-shaped Antarctic Peninsula Antarctic Peninsula, glaciated mountain region of W Antarctica, extending c.1,200 mi (1,930 km) N toward South America; in the south, volcanic peaks rise to c.11,000 ft (3,350 m). Most of its NE coast is fringed by the Larsen ice shelf. . The 650-ft. (220-meter) thick slab smashed into the Weddell Sea Weddell Sea (wĕd`əl), arm of the Atlantic Ocean, W Antarctica, SE of South America, bordered by the Antarctic Peninsula and Coats Land. The vast Ronne and Filchner ice shelves are at the head of the sea. at a speed described as "staggering" by glaciologist (glacier scientist) David Vaughn David Vaughn (born March 23 1973 in Tulsa, Oklahoma) is an American former professional basketball player who was selected by the Orlando Magic in the 1st round (25th overall) of the 1995 NBA Draft. of the British Antarctic Survey Based in Cambridge, the British Antarctic Survey (BAS) is the United Kingdom's national Antarctic operator and has an active role in Antarctic affairs. BAS is part of the Natural Environment Research Council and has over 450 staff. : "It's hard to believe that 720 billion tons of ice sheet has disintegrated in less than a month." The amount of ice lost? Enough to fill about 12 trillion 10-kilogram (22-pound) bags! Larsen B is now 40 percent of its original size, having lost 3,250 [km.sup.2] (803,088 acres) of ice over a 35-day period starting last January. It was the largest single Antarctic ice shelf collapse in 30 years. Scientists monitored the gradual decay of Larsen B over five years, but were startled star·tle v. star·tled, star·tling, star·tles v.tr. 1. To cause to make a quick involuntary movement or start. 2. To alarm, frighten, or surprise suddenly. See Synonyms at frighten. by its sudden accelerated demise. The ice shelf may have existed since the end of the last major ice age, about 12,000 years ago. Few dispute the cause of the collapse: Rapid-warming temperatures. The Antarctic Peninsula has warmed about 2.2 [degrees] C (4 [degrees] F) since the 1950s, a rate much faster than the global average. But why global warming has occurred is at the center of a fiery scientific debate: On one hand, many scientists say temperature increases are triggered by emissions of man-made heat-trapping gases like carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. released into the air by the burning of fossil fuels. In the atmosphere, the gases react with chemicals to create a shield that reflects heat back to Earth--a process called the greenhouse effect. Others claim warming temperatures are the result of a natural climate cycle, pointing to Antarctica's polar deserts, whose average temperatures may have cooled by about 0.6 [degrees] C (1 [degrees] F) in the past 14 years. What's your take on the collapse? To help form an opinion, visit the National Snow and Ice Data Web site at: nsidc.org |
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