An accurate picture of ice loss in GreenlandSeptember 30, 2008Researchers from TU Delft joined forces with the Center for Space Research (CSR) in Austin, Texas, USA, to develop a method for creating an accurate picture of Greenland's shrinking ice cap. On the strength of this method, it is now estimated that Greenland is accountable for a half millimetre-rise in the global sea level per year. These findings will be published in the scientific journal Geophysical Research Letters in early October. The research was based on data from the German-American GRACE (Gravity Recovery and Climate Experiment) satellites, two satellites that have been orbiting the earth behind each other since mid-2002. Deviations in the earth's gravitational field cause fluctuations in the distance between the satellites, which is measured to a precision of a millionth of a metre. As gravity is directly related to mass, these data can be used to plot changes in the earth's water balance, such as the disappearance of the ice caps. Satellite data of this kind are ideal for measuring areas such as Greenland, where the extreme conditions make local measurements very difficult. With this in mind, researchers from TU Delft and the CSR devised a method that would create a more accurate picture of the changes taking place in Greenland than had previously been possible. Sea level rise
Greenland lost an average of 195 cubic kilometres of ice per year between 2003 and 2008, which is enough to cause an annual increase in the global sea level of half a millimetre, or 5 cm over the course of the next century. A report recently published by the Dutch Delta commission estimated that the melting ice cap in Greenland would cause the sea level to rise by 13 to 22 cm by 2100. But these two figures do not necessarily contradict each other: whereas the first two years of the study showed a loss of 131 cubic kilometres of ice per year, during the last two years this figure had risen to 222 cubic kilometres per year, an increase of 70 percent. This sharp increase was mainly caused by the extremely warm summer of 2007, when more than 350 cubic metres of ice melted in just two months. However, it is not yet clear whether the ice will continue to melt at this rate during the next few years, as ice loss varies greatly from summer to summer. Long-term observations are needed to compile a reliable estimate of Greenland's contribution to the rising sea level during the next century. Patterns The method used also enables scientists to plot the loss of mass per region, thereby providing new insight into the patterns of ice loss. For example, for the first time since measurements were started, the extremely warm summer of 2007 saw a decrease in the ice mass at high altitudes (above 2,000 metres). It also became clear that the ice loss is advancing towards the North of Greenland, particularly on the west coast. The areas around Greenland, particularly Iceland, Spitsbergen and the northern islands of Canada, seem to be particularly badly affected. A follow-up study will focus on the influence of these smaller glaciers on the sea level. TU Delft Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. E Coli Gum Disease Liver Transplant Cardiac Death Ibuprofen Shopping Glucose HPV vaccine Brain function Pacemaker Giant Panda Dark Energy Biomarkers Muscular Dystrophy Laser Sepsis Cholesterol Levels Macular Degeneration Biotechnology Chimpanzee Mitochondrial Eye Movement Imaging technique Chronic Kidney Disease Glacier
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Related Sea Level Current Events and Sea Level News Articles Mangrove-dependent animals globally threatened More than 40 percent of a sample of amphibians, reptiles, mammals, and birds that are restricted to mangrove ecosystems are globally threatened with extinction, according to an assessment published in the July/August issue of BioScience. Close relationship between past warming and sea-level rise In a paper in Nature Geoscience, a team from the National Oceanography Centre, Southampton (NOCS), along with colleagues from Tübingen (Germany) and Bristol presents a novel continuous reconstruction of sea level fluctuations over the last 520 thousand years. Ice Sheets Can Retreat Modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid shrinkage or retreat, according to new findings by paleoclimatologists at the University at Buffalo. Climate change is already having an impact in the midwest and across the US Extreme weather, drought, heavy rainfall and increasing temperatures are a fact of life in many parts of the U.S. as a result of human-induced climate change. Study: Greenland ice sheet larger contributor to sea-level rise The Greenland ice sheet is melting faster than expected according to a new study led by a University of Alaska Fairbanks researcher and published in the journal Hydrological Processes. Bone bed tells of life along California's ancient coastline In the famed Sharktooth Hill Bone Bed near Bakersfield, Calif., shark teeth as big as a hand and weighing a pound each, intermixed with copious bones from extinct seals and whales, seem to tell of a 15-million-year-old killing ground. Height of large waves changes according to month "Anybody who observes waves can see that they are not the same height in winter and summer, but rather that their height varies over time, and we have applied a 'non- seasonal' statistical model in order to measure extreme events such as these", Fernando J. Méndez, an engineer at the Institute of Environmental Hydraulics at the University of Cantabria and co-author of a study published recently in the journal Coastal Engineering, tells SINC. Lesson from the past for surviving climate change Research led by the University of Leicester suggests people today and in future generations should look to the past in order to mitigate the worst effects of climate change. Melting Greenland Ice Sheets May Threaten Northeast United States, Canada Melting of the Greenland ice sheet this century may drive more water than previously thought toward the already threatened coastlines of New York, Boston, Halifax, and other cities in the northeastern United States and Canada. Jeepers Creepers! Climate Change Threatens Endangered Honeycreepers As climate change causes temperatures to increase in Hawaii's mountains, deadly non-native bird diseases will likely also creep up the mountains, invading most of the last disease-free refuges for honeycreepers - a group of endangered and remarkable birds. More Sea Level Current Events and Sea Level News Articles |
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