AUSTIN (KXAN) – New models released by the University of Texas revealed that Greenland’s glacier fronts, the part touching the ocean, may be melting 100-times than originally thought. Previous models predicted melting along the island’s coast did so using data collected from glaciers in Antarctica.
“What we did in previous models was our best guess on available data,” said Kirstin Schulz Ph.D., a researcher at UT’s Oden Institute for Computational Engineering and Sciences.
The new data used in the model was collected by Rebecca Jackson from Rutgers University using robotic kayaks. The kayaks scanned Alaska’s LeConte Glacier, which has a similar make up to Greenland’s glaciers.
“It is the only data set of this kind that exists so far,” Dr. Schulz said.
Gathering data from Greenland directly is dangerous. Older models used data collected from Antarctica. Details about the new model were published in Geophysical Research Letters. It took a year and a half for the new computer model to be developed.
How are the glaciers melting?
Glaciers are melting because of two things: warming air on top of the glacier and warm ocean water at the base of the glacier, Dr. Schulz said.
The new model, and the new figure of 100-times faster melting, is specifically about melting occurring at the base of the glacier touching the ocean. “This ice ocean interaction is just a super big point of uncertainty.”
“The glaciers flow very slowly, but they flow into the ocean. And then you have like a couple of 100 meters deep ice front and direct contact with relatively warm, at least liquid water. And well, that melts the ice.”
Why were the original glacial melt models so wrong?
The original models used data from Antarctica’s floating glaciers. “The ice sheets in Antarctica, they are more stable, they are horizontal, you can drill through them,” Dr. Schulz said.
This made collecting data on these glaciers safer. Greenland’s glaciers are chaotic by comparison.
“It’s absolutely difficult to get close enough to the vertical glacier fronts to make measurements because well, they’re calving [this is when] pieces fall off.”
The glaciers sit atop the island with melting occurring along fjords. The edges of the glaciers are sharp angles.
Large chunks of ice fall into the water, while at the same time melting is occurring atop the ice. This melting atop the glaciers causes rivers of melt water to form within the glacier, which then blast out below the surface of the ocean.
This melting causes the glacier to flow or retreat into the ocean, falling apart as it melts further.
How will the new glacier melt models be used?
The new models better reflect the “reality” of the glaciers. For glaciologists, the data will be used to study how glaciers on the island are transforming, Schulz said.
“How much meltwater is coming from the glaciers? How is distributed in the ocean? For all of that, what comes next?”
For people researching the ocean, the new model will help them get a better understanding of how the glacier’s movement is impacting the nearby water.
Why should you care about melting glaciers?
That liquid water is fresh, compared to the salty water in the ocean, and it is also cold.
Fresh water is lighter than salt water, which means it floats on the ocean’s surface. “It matters a lot if it melts at depth or if it melts at the surface.”
Ocean currents are currently endangered because of the melting glaciers. A 2022 report published in Nature Climate Change found that the Atlantic Meridional Overturning Circulation (AMOC) could shut down due to this.
“What was solid is now liquid in the ocean. So the sea level is rising. But it also has an effect on the larger scale ocean currents,” Schulz said.
“When these large scale ocean circulations are affected, that has implications for regional weather patterns.”
The AMOC provides warm water from near the equator to the US’ East Coast and Europe. Scientist with the Intergovernmental Panel on Climate Change warn that if this were to occur, temperatures in Europe and in eastern North America could drop by nine degrees Fahrenheit.
The last time Greenland’s glaciers melted was in the Eemian interglacial period about 125,000 years ago.
Ice covers about 80% of the Nordic nation and is the second largest stretch of glaciers on Earth. If all the glaciers were to melt, the global sea level could rise by 20 feet, according to a report published in 2000.