Satellite data has given scientists hints about how, when, and why Greenland’s glaciers are shrinking and reveal a sharp improve in glacial retreat starting about 2000, in accordance with new analysis introduced this week.
In a presentation on the annual meeting of the American Geophysical Union, scientists launched time-lapse satellite images courting again 34 years of about 200 glaciers on the island of Greenland. The images are the first to check Greenland’s glacier retreat—when a glacier shrinks again from the ocean, pulling inland—and the velocity at which the glaciers are retreating.
To evaluate the glaciers, King analyzed images from the NASA-U.S. Geological Survey’s Landsat missions, an ongoing venture to observe the Earth’s floor from space. The satellites survey a lot of the Earth’s floor; scientists at AGU additionally introduced on adjustments to glaciers and ice fields in Antarctica and Alaska.
Meaning the glaciers aren’t simply shrinking in a single a part of the ice sheet overlaying Greenland—within the north or south, for instance—however, that the majority glaciers throughout the nation have retreated.
That issues for the glacier’s size: Prior to 2000, the ice that calved from the glacier was roughly equal to the quantity of snow that accumulated on the ice sheet—basically, the mass lost to calving was a wash, as a result of it was changed by new snowfall.
However, after 2000, that equilibrium went out of whack: The glacier is losing ice quicker than snow is falling to replace it. King stated the triggers for that retreat range by area, and however, in southeast Greenland, the retreat was largely attributable to warming ocean waters that melted the entrance of the glaciers.