The melting that caused Zachariae Glacier to shrink came from both warming air above and warming water below the ice shelf.
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Zachariæ Isstrøm is a giant glacier in the northeast of Greenland. Together, these two glaciers have enough water to raise global sea levels by nearly 40 inches.
Zachariæ Isstrøm, a glacier in northeast Greenland, began a rapid retreat in recent years, a new study reports.
A nearby north Greenland glacier, Nioghalvfjerdsfjorden – often called “79” for ease of pronunciation – was also melting quickly, the study said.
“During the first 25 years of the survey, the glacier was in balance, so it was accumulating the same amount of ice through snow”, Mouginot said.
Ongoing research into the health of ice sheets and glaciers in Greenland and Antarctica is supported by funding from NASA’s Cryospheric Sciences Program.
“The grounding line is where the ice sheet starts to float and is where the ice flux was measured”, said Paden, who collaborated with researchers from the University of California Irvine and the California Institute of Technology.
And what seems to be the major case for all of these cases, is warm ocean waters reaching the deep bases of marine glaciers. The Zachariae Isstrom glacier is now melting at a rate of five billion tons every year, which can be quite devastating since the glacier hold about five percent of the Greenland ice sheet, or about 35,440 square miles. If so, that would be a little under a third of the total global sea level rise, which is now 3.24 millimeters per year.
The ice within them is also moving towards the sea faster – so they are dumping ever more ice in the sea.
According to a new study published Thursday, the speed in which the glacier was thawing came about as a big surprise to the researchers. The study did not disclose when the glacier will melt away to nothing.
Nevertheless, if we take into account all glaciers that are shedding ice now, many people would be affected. Joughin thinks Zachariae may not catch up to the latter, since the basin into which it is retreating is not as deep. Atop the ice sheet, vast meltwater lakes can form and then suddenly vanish in a matter of hours, draining rapidly as crevasses open beneath them and they spill into the ice sheet’s depths. The combined data reveal the changing shape, size, and position of Greenland glaciers over the past four decades.
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The United Nations panel of climate scientists estimates that sea levels may rise by 26 to 82 centimetres this century. Given the continued warming and the shape of the valley beneath it, the researchers write, “We project that [Zachariae Glacier] may continue retreating rapidly for another 20-30 years”. The change will definitely increase sea level in the coming years. The floating ice shelf that protects it is thinning and could soon be lost. “Now this has started, it will continue until it retreats to a ridge about 30km back which could stabilise it and perhaps slow that retreat down”. For it, too, appears to be exposed to warmer ocean water. “When you add up all the glaciers that are retreating, it will make a difference to a large number of people”. Global warming would become unmanageable if this happens. And that’s also, of course, the hardest one to answer. Unfortunately, the glacier is now breaking up and calving high volumes of icebergs, releasing them into the ocean.
