New large scale study Greenland’s ice seat crevas ice indicates that these cracks are expanding faster as the climate warms up.
Crebus is a wedge -shaped fracture and crack that opens in the glacier where the ice begins to flow faster. They can grow to more than 300 feet, thousands of feet in length, and several hundred feet. The water from the melting of the snow on the surface flows the crevas to the bottom of the ice, binds with other hidden streams, and forms a vast drainage system that affects the flow of glaciers and ice sheets.
This study shows that Crebus is expanding faster than previously detected, and 50-90 % of the water flowing through the Greenland ice sheet passes Crebus. Ice bed and rock flowing. Both stated that both mechanisms can accelerate the flow of the ice itself. Thomas ChudrillHe is a glaciologist at the University of Dalam University and a new research.
“Understanding Crevas is the key to understanding how this emission will evolve after the 21st century,” he said.
Greenland Ice researchers said, “Because the glaciers are accelerating according to the warm ocean temperature, the crevas filled with melted water can force fracture in the ice. “However, there has been no data on how fast this is happening in the entire Greenland ice sheet.”
With the three -dimensional image of Crevas, researchers have obtained the most accurate estimation of the total amount so far. The results indicate that Crebus has greatly expanded between 2016 and 2021.
“And they grow almost in rock steps with the increase in melt water emissions to iceberg and the sea,” said Cadrley. “It’s reasonable, isn’t it? The glacier is speeding up due to the effects of the warming sea. Speed up will flow faster.”
The ice on the glacier surface generally flows faster than the base. These are slower due to friction on the moving surface. He explained that the difference in speed causes a crack.
He stated that this study emphasizes a new feedback that accelerates mass loss from glaciers through the change in ice sheets and the emission of glaciers. XAVIER FETTWEISA professor at the Liege University, which was not part of a new research.
“It’s difficult to evaluate the importance of this positive feedback,” he said.
He said that it is necessary to consider how various complicated interactions work to calculate the total emission of ice from Greenland.
For example, as the glacier retreats from the coast, it is shown that the direct discharge of the iceberg has reduced direct discharge to the sea. He said it would slow the melting of the iceberg to the rise of the sea surface.
However, the same retreat, when the inclined tongue of the floating ice retreats from the sea to the land, both the melting of the iceberg and the increase in delivery on the low edge cover the remaining part of the ice. Soak
The stress spreads and deepens the crevas studied by Chadry. This is a feedback cycle that can speed up the collapse of Greenland ice sheets.
Greenland melted ice affects millions
2020, researcher Calculation The Greenland ice sheet loses about 9 billion tons of water every hour. The total of the annual freshwater flow rate off Greenland is almost equal to the annual flow of the Amazon River in Gigaton per year. Geological survey of Denmark and Greenland Who led a comprehensive 2020 research tracking emission from Greenland from 1986 to 2020? When all ice melts, increase the sea surface by about 23 feet (7 meters).
Completely meltdown is expected to take thousands of years, but there are many Scientific evidence From the rapid global past rapid climate warming era, it shows a pulse of rapid global ice melt, and the sea surface rises up to 13 feet (4 meters) per century. Greenland ice can be made at the current speed of melting Contribute about 3 feet The sea surface of (1 meter) rises by 2100.
Some coastal areas have already struggled to adapt to the rise of the sea level, and there is a risk that millions of people around the world will lose land and living. Greenland ice is one of them The biggest contribution to the sea level riseAnd projecting the meltdown speed is an important climate science goal for people to prepare.
The first inventory of Klebus, which crosses the entire Greenland ice sheet, is helpful to do it, and William Corgan, a professor of glacial and climate of Denmark and Greenland geological surveys, is involved in this research. I didn’t.
“This is the first study that the expansion of the crabas zone is only ubiquitous throughout the Greenland outlet glacier, which has been accelerating in recent years,” he said.
“The absolute number is large,” he added. “We are talking about the fact that several thousands of kilometers of ice sheets are crabs and several hundred square kilometers are crevas during the observation period.”
Corgan said this study provides an unprecedented details of the distribution of crevas at various altitude and how the cracks and its distribution are changing. “I think there was a similar feeling when the first inventory of the moon crater was created. You always knew they were there, but you can’t count them individually. did.”
Various reports from ice sheets in this field have confirmed the results of research.
“If you’re working on the ice sheet every year, you’ll be familiar with the increase in crevas on your local site,” he said. “Especially in the blue ice area, glaciers are generally faster, and snowfall is generally decreasing. I hope that more crevas will be seen.”
Corgan has also emphasized that the new survey has also shown an increase in feedback risks that are not included in the impact on the climate. It suggests that melting can accelerate beyond what science already predicted.
“I know the appearance of Crevas can cause many feedback due to ice loss,” he said. “The so many feedback to strengthen ice loss has a significant role in the reaction of Crevas than the ice sheet plan for climate change.”
This story originally appeared Internal climate news。
