Researchers led by Steve Lermit, a satellite expert at Delft University of Technology in the Netherlands, used satellite data to document the development of damaged areas from 1997 to 2019. Images showed more cracked areas and exposed fractures in the glaciers.
“We knew those giants were asleep and this was the one who was losing a lot of miles (of ice), but there is still a lot of uncertainty and how much.” “These ice shelves are in the early stages of disintegration, they begin to crack.”
The Thwets Glacier is one of the largest and most volatile ice streams in Antarctica. It is more than 192,000 square kilometers (74,000 square miles) in size – the area is similar to the American state of Florida or Great Britain.
So what is happening to glaciers now?
Human-induced warming in our oceans and atmosphere is weakening the ice sheets of the planet due to the increasing release of greenhouse gases emitted by heat.
Damage researchers pointed to the weakness of glacier scissor margins – spaces on the edges of floating ice shelves where fast moving ice meets slow moving ice or rock below.
“Normally an ice shelf acts like slow traffic. It floats on the ocean but it pushes the ice traffic behind it.” Said Larmit. “So if you weaken this slow car, the ice dissolves more quickly.”
That’s exactly what the researchers observed – and they believe that these fragile parts of the glacier will accelerate mass ice loss. The study makes the case that this process should include models that project sea surface development, which is not currently part of it.
Researchers have found that the shear margin rupture of the Pine Island Glacier has been documented since 1999, with their satellite image showing that the damage increased dramatically in 2016.
Similarly, damage to the Thaits Glacier began to move further upwards in 2016 and fractures began to open rapidly near the glacier’s grounding line, where ice meets the bed of rocks.
Researchers have warned that the process is creating a feedback loop – where weakened ice shelves are accelerating damage to the glacier’s weaker shear margins, which in turn leads to more damage and splitting of the ice shelf.
Isabella Velikogna, a professor of earth systems science at the University of California, who was not involved in the study, said: That sea level will rise faster than currently forecast. “
Villegogna said there are other processes that play a “much bigger role” in glacier evolution, such as the “rate of withdrawal of the mandatory grounding line by the warm sea.”
Glaciers in trouble
The cavity hidden under the ice shelf is likely to be the passage through which warm ocean water goes to the grounding line below the ice shelf, they said.
Over the past three decades, the rate of ice damage caused by Thwits and its neighboring glaciers has more than quadrupled. If thwites collapse, it could lead to an increase in sea level of about 25 inches (64 centimeters).
The region’s ice sheet is the second largest in the world behind Antarctica, and its annual melting contributes more than one millimeter to sea level each year.
These recent findings from Antarctica show that glaciers are “weakening from all angles,” Lermite said.
“The biggest weakness in this part of Antarctica is coming from below,” he said. “Warm ocean water reaches the base of glaciers and weakens them. We’ve seen that they get so weak that they get faster and once they get faster, the shear margins get faster and break. . “
Velegogna said the research “points to the heel of the other Achilles of the system, conducive to rapid retreat and a stimulus for another climate change.”
“It seems that the sooner we develop these systems, the sooner we’re looking for reasons to disappear than we thought.” “We must act quickly to control climate change to save our future. Now is the time to act.”
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