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Greenland thaw is faster and anticipates a large sea rise

Greenland thaw is faster and anticipates a large sea rise

By Anastasia Gubin

"TheGreenland ice sheet it is the second largest mass of ice on Earth. Covers an area about five times the size of New York State and Kansas combined, and if it melts completely, the oceans could rise six meters (20 feet), "the University of Buffalo noted on December 15.

"Coastal communities from Florida to Bangladesh would suffer extensive damage”Added the report.

According to the authors of the new study, current models "are too simplistic to accurately predict future sea level rise," for the climate change.

The new data allowed to conclude that “Greenland may lose ice faster in the near future than previously thought”Warned Beata Csatho, associate professor in the Department of Geology.

Professor Csatho stressed that for the first time, there is "a global vision of how all the glaciers in Greenland have changed in the last decade."

Using data from the satellite and the NASA ICESat spacecraft and Operation IceBridge, the team reconstructed changes in the height of the Greenland ice sheet at nearly 100,000 locations between 1993 and 2012. It was found that some of the ice it was lost by merging and on the other side by breaking and drifting across the ocean.

The analysis also found that the Greenland ice sheet lost about 243 metric gigatons of ice each yearor - equivalent to about 277 cubic kilometers of ice per year between 2003 and 2009.

"This loss is estimated to have added about 0.68 millimeters of water to the oceans annually," highlights the document.

"This information is crucial for the development and validation of numerical models that predict how the ice sheet may change and contribute to global sea level in the next hundred years," said Cornelis J. van der Veen, professor in the Department of Geography. from the University of Kansas, who interpreted glaciological changes.

In the past only the Jakobshavn, Helheim, Kangerlussuaq and Petermann glaciers were studied in detail, and taking these data they predicted the behavior of the entire ice sheet.

“The new research shows that the activity at these four locations may not be representative of what happens to glaciers across the entire ice sheet. In fact, glaciers undergo patterns of thinning and thickening, which current climate change simulations do not take into account, ”Csatho said.

Greenland has 242 glaciers of more than 1.5 kilometers of ice sheet in Greenland, and "what we see is that their behavior is complex in space and time," said the geologist. "Local geological and climatic conditions, local hydrology - all these factors have an effect. Current models do not address this complexity," he added.

For example, the team identified a large ice loss in the southeastern part of Greenland that current models have not identified.

Greenland ice loss varies from year to year and region to region, and glaciers not only gradually lose mass as temperatures rise. "That is one reason it is difficult to predict their response to global warming," the report said.

Scientists found that some of Greenland's glaciers thickened even as the temperature rose. Others exhibited accelerated weight loss. Some show both thinning and thickening, with sudden changes.

To build better models of sea level rise, the team divided the 242 glaciers in Greenland into seven large groups based on their behavior between 2003 and 2009.

They proposed in turn that by selecting a couple of examples of glaciers that are representative of the whole, this can help create models to provide a more complete picture of what is happening.

The work of Csatho and his team is a new alert to the effects of man-made climate change. High emissions of CO2 and its equivalents are increasing the temperature of the planet. In some regions such as Australia, in the month of November 2014, these exceeded 2.19 degrees Celsius, the average maximum temperature, and the minimum by almost 2 degrees.

In an additional project, the team from the University of Buffalo is investigating why different glaciers respond differently to global warming.

Among the factors analyzed are the temperature of the surrounding ocean, the level of friction between a glacier and bedrock, the amount of water under a glacier, and the geometry of the fjord.

"The physics of these processes are not well understood," Csatho said in the university report.

The Epoch Times


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