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In the new study, the scientists created a decadelong record ofchanges in Greenland outlet glaciers by producing velocity mapsusing data from the Canadian Space Agency's Radarsat-1 satellite,Germany's TerraSar-X satellite and Japan's Advanced LandObservation Satellite. They started with the winter of 2000-01 andthen repeated the process for each winter from 2005-06 through2010-11, and found that the outlet glaciers had not increased invelocity as much as had been speculated. "In some sense, this raises as many questions as it answers. Itshows there's a lot of variability," said Ian Joughin, aglaciologist in the UW's Applied Physics Laboratory who is acoauthor of the Science paper and is Moon's doctoral adviser. Other coauthors are Benjamin Smith of the UW Applied PhysicsLaboratory and Ian Howat, an assistant professor of earth sciencesat Ohio State University. The research was funded by NASA and theNational Science Foundation. The scientists saw no clear indication in the new research that theglaciers will stop gaining speed during the rest of the century,and so by 2100 they could reach or exceed the scenario in whichthey contribute four inches to sea level rise. "There's the caveat that this 10-year time series is too short toreally understand long-term behavior," Howat said. "So there stillmay be future events tipping points that could cause largeincreases in glacier speed to continue. Or perhaps some of the bigglaciers in the north of Greenland that haven't yet exhibited anychanges may begin to speed up, which would greatly increase therate of sea level rise." The record showed a complex pattern of behavior. Nearly all ofGreenland's largest glaciers that end on land move at top speeds of30 to 325 feet a year, and their changes in speed are small becausethey are already moving slowly. Glaciers that terminate in fjordice shelves move at 1,000 feet to a mile a year, but didn't gainspeed appreciably during the decade. In the east, southeast and northwest areas of Greenland, glaciersthat end in the ocean can travel seven miles or more in a year.Their changes in speed varied (some even slowed), but on averagethe speeds increased by 28 percent in the northwest and 32 percentin the southeast during the decade. "We can't look at one glacier for 100 years, but we can look at 200glaciers for 10 years and get some idea of what they're doing,"Joughin said. Moon said she was drawn to the research from a desire to take thelarge store of data available from the satellites and put it into ausable form to understand what is happening to Greenland's ice. "We don't have a really good handle on it and we need to have thatif we're going to understand the effects of climate change," shesaid. "We are going to need to continue to look at all of the icesheet to see how it's changing, and we are going to need tocontinue to work on some tough details to understand how individualglaciers change.". The e-commerce company in China offers quality products such as Nokia Phone Pouches , China Personalised Ipad Covers, and more. For more , please visit Apple Iphone Protective Cases today!
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