One of Greenland’s glaciers is losing five billion tonnes of ice a year to the ocean, according to researchers. While these new findings may be disturbing, they are reinforced by a concerted effort to map changes in ice sheets with different sensors from space agencies around the world.
It is estimated that the entire Zachariae Isstrom glacier in northeast Greenland holds enough water to raise global sea levels by more than 46 cm.
Jeremie Mouginot, from the University of California Irvine in the USA and lead author of the paper published in the journal Science, said, “The shape and dynamics of Zachariae Isstrom have changed dramatically over the last few years.
“The glacier is now breaking up and calving high volumes of icebergs into the ocean, which will result in rising sea levels for decades to come.”
These current findings are a prime example of how different satellite observations and measurements from aerial surveys are being used from various space agencies including ESA, the Canadian Space Agency, NASA, the German Aerospace Center, the Japan Aerospace Exploration Agency and Italy’s space agency, ASI.
Over the last nine years the Polar Space Task Group has been coordinating the collection of radar data over Greenland and Antarctica.
ESA radar observations going back to the ERS and Envisat satellites through to Sentinel-1A were used in the new study.
In addition, the group relied heavily on data from Canada’s Radarsat-1 and -2, Germany’s TerraSAR-X and TanDEM-X, Japan’s ALOS and Italy’s Cosmo-Skymed to ensure a continuous record of ice-sheet changes through to the launch of Sentinel-1A.
Using these many sources, scientists determined that the bottom of Zachariae Isstrom is being rapidly eroded by warmer ocean water mixed with growing amounts of meltwater from the ice sheet surface.