Alaskan glacier races forward.The term "glacial" can describe the pace of lines at the Post Office or the plodding progress of Congress. But there's nothing slow about the speed of the Bering Glacier Bering Glacier is a glacier in the U.S. state of Alaska. It currently terminates in Vitus Lake south of Alaska’s Wrangell-St. Elias National Park, about 10 km (6 mi) from the Gulf of Alaska. , the largest stream of ice on the North American North American named after North America. North American blastomycosis see North American blastomycosis. North American cattle tick see boophilusannulatus. continent. Last spring, a small patch of the glacier dramatically accelerated its normally stately flow downslope n. 1. a downward slope. Noun 1. downslope - a downward slope or bend declivity, declination, declension, fall, decline, descent downhill - the downward slope of a hill (SN: 8/7/93, p.95). Since then, the surging region has spread to include half the 5,175-square-kilometer surface area of the glacier, says Bruce F. Molnia of the U.S. Geological survey The term geological survey can be used to describe both the conduct of a survey for geological purposes and an institution holding geological information. A geological survey in Reston, Va. The surge started in the middle of the glacier and expanded from there until it reached the end of the Bering in late August. Photos taken by airplane on July 10 (top) and September 10 (bottom) show the advance of the glacier's terminus (arrow), which moved forward more than 1,500 meters in just three weeks, spreading into part of Vitus Lake Vitus Lake is a lake in Alaska. It is 23 km (14 mi) long and 9 km (5.5 mi) wide. It is named for Vitus Bering, leader of the 1741 expedition to Alaska. Vitus Lake forms the southern limit of the Bering Lobe, outlets via the Seal River to the Gulf of Alaska. at the end of the glacier. In late August and early September, the glacier's foot marched forward at speeds approaching 100 meters per day, nearly 100 times its normal pace. Ice calving calving act of parturition in a bovine female, and presumably in any animal that bears a calf as its newborn. See also block calving, ease of calving. calving-to-conception interval off the terminus has filled much of Vitus Lake with icebergs, which appear white in the pictures. The glacier has surged roughly once every two decades during the 20th century, with the last such event ending in 1967. Studies on smaller glaciers suggest that they surge when the plumbing system below the ice gets clogged with silt. Water that normally flows out from under a glacier then accumulates beneath the ice, eventually lifting it off the bedrock. That reduces friction between the ice and ground, sending the glacier sliding downhill. Since they don't have instruments set up under the Bering Glacier, scientists can't be sure that the same process caused points in that direction there. But some circumstantial evidence circumstantial evidence In law, evidence that is drawn not from direct observation of a fact at issue but from events or circumstances that surround it. If a witness arrives at a crime scene seconds after hearing a gunshot to find someone standing over a corpse and holding a points in that direction. Molnia says clients studying the glacier and pilots flying over it this year have noted large numbers of ephemeral lakes on the surface of the ice, suggesting that the drainage system through the glacier has become plugged. Past surges of the Bering Glacier have lasted about 18 months and have, at times, filled virtually all of the Vitus Lake basin with ice. Once the glacier slows, its foot retreats back-up-slope, reopening the lake basin. |
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