Time melts AntarcticaIt is the largest glacier in the world, and its rapid deterioration can end with the complete collapse of ice shelves in just a few years, researchers said on Monday (December 13) in the American Geophysical Union. AGU) warned at a virtual press conference at the annual meeting.
The Sweat Glacier in western Antarctica EarthIt spans approximately 80 miles (120 km) and extends to a depth of approximately 2,600 to 3,900 feet (800 to 1,200 m) along its grounding line. Glaciers migrate from the land-based ice sheets of the Amundsen Sea to floating ice shelves. Ocean. Swaite is sometimes referred to as the “end glacier” because its collapse can cause a cascade of glacial collapses in Antarctica. According to the latest research on frozen continents, the end of diminishing glaciers may come earlier than expected.
Warm sea water does more than just melt the weights from below. It also loosens the grip of the submerged seamount glaciers below, making it even more unstable. As glaciers weaken, they are more prone to surface cracks that can spread to shatter the entire ice shelf “like a car window.” This can happen soon after three years, researchers said at the AGU in New Orleans. And online.
Over the last decade, Swait’s observations have shown that glaciers are changing more dramatically than any other ice and marine system in Antarctica. This is due to what humans have caused. Climate change Global warming of the atmosphere and ocean is progressing. Thwaites has already lost an estimated 1 trillion tonnes (900 billion metric tonnes) of ice since 2000. Annual ice loss has doubled in the last three decades and is now about 50 billion tonnes (45 billion metric tonnes) more ice than annual snowfall. According to International Thwaites Glacier Collaboration (ITGC).
If Swaite completely collapses and releases all its water into the ocean, sea levels around the world will rise by more than two feet (65 centimeters) and are one of the AGU presenters and the Institute for Environmental Sciences (CIRES). ..
“And that could lead to sea level rise up to an additional 10 feet. [3 m]If it attracts the surrounding glaciers. ” Said in a statementSee the possible weakening effects of one ice shelf collapse on other nearby glaciers.
Thwaites are changing rapidly and can have a significant impact on global sea level rise, so more than 100 scientists in the United States and the United Kingdom have eight research projects to observe glaciers from top to bottom. We are cooperating with. Results from some of those teams were presented at AGU.
“We are approaching the midpoint of international Sweat Glacier collaboration,” Skambos said in a briefing. “It will take a few more years to collect and integrate more results, so we can better understand that this glacier is moving forward.”
These findings, and ongoing work by ITGC and other scientists in Antarctica, include policymakers’ strategies for tracking the effects of glacier melting on sea level rise over the coming decades, and their surroundings. Notify you of how it will affect the coastal community. According to the presenter, the world.
Melt from below
At Swaite, scientists pierced the ice and looked into the ocean hundreds of meters below, while other researchers deployed remote-controlled diving robots to study glacier ground zones. They measured the temperature, measured the salinity of the sea, and found that the deep water under the ice was warm enough to cause considerable melting.
Another group of scientists said that tidal activity could interact overhead with ice to actively pump hot water further inland through channels already carved by melt, thereby accelerating the deterioration of weights. Lizzie Klein, an adjunct professor at Lewis and Clark College, said he discovered that. Portland, Oregon.
“At low tide, the floating ice shelves sink,” Clyne told AGU. “It acts like a kind of lever and can pull the section that can actually draw water a little inland, and when the water level rises at high tide, the opposite happens. Floating. The section goes up. ”Clyne explained that this up-and-down movement, known as a tidal pump, draws more water inland and further weakens the glacier.
“Hundreds of icebergs”
The once hard ice blocks of Sweat, which previously helped to organize the ice shelves, have also collapsed. According to AGU presenters, the glacier’s icy “tongue” (part of the ice shelf protruding toward the sea) is “just a loose cluster of icebergs, a more stable part of this eastern part of the ice shelf. It no longer affects the ice shelf. ” Erin Pettit, Associate Professor of Geophysics and Glaciology at Oregon State University. The stiffer tongue slowed the flow of eastern ice shelves into the sea. However, the loss of that resistance has changed the flow of the eastern shelves over the last decade. According to Pettit, the cracks spread rapidly throughout the ice, and that part of the shelf is likely to break “in hundreds of icebergs” within just a few years.
The effect is like a car window, “there are some slowly propagating cracks that suddenly get over the bumps of the car and everything starts to shatter in all directions,” she said. ..
According to Pettit, some of Sweat’s ice changes are so rapid and dramatic that scientists say they happen in real time, such as a huge rift in the eastern ice shelf two years ago. I am observing. A recent series of satellite images showed that the cracks were getting longer towards where the researchers were planning to set up field sites for the season. The crack wasn’t moving fast enough to threaten fieldwork that year, but it was still a cool moment to see its mysterious progress. Researchers nicknamed the crack “dagger,” Pettit said in a briefing.
The immediate forecasts for the Swait ice shelves are harsh, but the long-term forecasts for the rest of the glaciers are less certain. If the shelves collapse, glacier currents are likely to accelerate rapidly towards the ocean, some of which can triple in speed. Other chain reactions may also contribute to the accelerated crushing and melting of ice, Scambos said at AGU. However, according to the briefing, the time frame for these changes will be decades instead of years.
Meanwhile, the ITGC team will continue to monitor and analyze changes in ongoing interactions between Swait’s glaciers, ice shelves, and oceans to help world leaders and policy makers prepare for the next. ..
“It will help characterize what the next century will look like from this part of Antarctica,” Skambos said. “We think it will be guided by the changes in the Sweat Glacier.”
Originally published on Live Science.
“Doomsday Glacier” can reach its fate within 3 years
Source link “Doomsday Glacier” can reach its fate within 3 years
The post “Doomsday Glacier” can reach its fate within 3 years appeared first on Eminetra.