Friday 1st February 2019
14 billion tons of ice: so much fits into the cavity found by NASA researchers under a glacier at the South Pole. Above all in the last three years they have contributed to massive melting.
At record speed, a huge cavity is growing under a glacier in the Antarctic. It is ten kilometers long and four kilometers wide and as large as two-thirds of the Manhattan area, writes the researchers of the Jet Propulsion Laboratory (JPL) of the US Space Agency Nasa in the journal "Science Advances".
Much of the ice has melted in the last three years, the resulting cavity is almost 300 meters high. It was a disturbing discovery, NASA said. Now it must be explored how the fusion process affects sea level. The cavity, which once contained 14 billion tons of ice, is located under the Thwaites glacier in the Western Antarctic. The rock below the glacier is much lower than the sea level. Most of the ice has melted by penetrating seawater, the researchers write.
"We thought for years that Thwaites were not firmly tied to clandestinity," says coauthor Eric Rignot. With the new satellites, it was now possible for the first time to accurately measure the change in the glacier and the extension of the cavity. Since 2010, Nasa satellites have been observing the glacier with high-resolution radar. "The size of the cave under the glacier plays an important role in the fusion process," says the first author Pietro Milillo. "If more heat and water come under the glacier, it melts faster."
The entire Thwaites glacier has the size of Florida and is currently responsible for 4% of the sea level rise. If the entire glacier had melted, the oceans could increase by about 65 centimeters, according to the NASA statement. "Understanding how the ocean melts this glacier is essential to calculate the impact this has on ocean uplift over the next few decades," says Rignot.