Scientists say melting of Greenland glaciers worse than thought

Washington: A new research has warned that many large glaciers in Greenland are at greater risk of melting from below.

According to new maps of the seafloor around Greenland created by an international research team, many large glaciers in Greenland are at greater risk of melting from below than previously thought.

Researchers from the University of California, Irvine; NASA’s Jet Propulsion Laboratory, Pasadena, California; and other research institutions combined all observations their various groups had made during shipboard surveys of the seafloors in the Uummannaq and Vaigat fjords in west Greenland between 2007 and 2014 with related data from NASA's Operation Icebridge and the NASA/US Geological Survey Landsat satellites.

The findings, published in Geophysical Research Letters last month, showed “the glaciers in Greenland are more sensitive to climate change than previously thought.

"While we expected to find deeper fjords than previous maps showed, the differences are huge," said Eric Rignot of UCI and JPL, lead author of a paper on the research. "They are measured in hundreds of meters, even one kilometer [3,300 feet] in one place." The difference means that the glaciers actually reach deeper, warmer waters, making them more vulnerable to faster melting as the oceans warm.

About 90 percent of Greenland's glaciers flow into the ocean, including the newly mapped ones.

The new study also shows that the older maps were wrong.

Coauthor Ian Fenty of JPL noted that earlier maps were based on sparse measurements mostly collected several miles offshore.

“Mapmakers assumed that the ocean floor sloped upward as it got nearer the coast. That's a reasonable supposition, but it's proving to be incorrect around Greenland,” he added.

The researchers also found that besides being deeper overall, the seafloor depth is highly variable.

"These data help us better interpret why some glaciers have reacted to ocean warming while others have not," Rignot said.

(Source: NASA)