Researchers led by Steve Lermit, a satellite expert at Delft University of Technology in the Netherlands, used satellite data to document the growth of damaged areas from 1997 to 2019. The images show areas with high defects and open fractures in the glaciers.
“We knew they were sleeping giants and these were people who were losing a lot of miles (of ice), but how far and how much still remains a great uncertainty,” Lermit said. “These ice shelves are in the process of breaking down, they’re starting to crack.”
The Thaiweat Glacier is one of the largest and most unstable ice streams in Antarctica. It is a vast cluster of over 192,000 square kilometers (74,000 square miles) – the size of Florida in the United States, or the size of Great Britain.
So what is happening to glaciers now?
The increasing release of heat-trapping greenhouse gases from human oceans and the human environment is weakening the planet’s ice sheets.
Damaged researchers point to the weakening of the shear margin of glaciers – on the edge of floating ice where high-speed ice is found under slow-moving ice or rock.
“Normally the ice shelf acts like slow traffic. It floats on the ocean but it suppresses the ice traffic behind it,” Lermit said. “So if you weaken this slow car, the ice discharges faster.”
Researchers have seen exactly this – and they believe that these very fragile parts of the glacier will increase the loss of mass ice. The study makes it a case that this process should be included in models that show sea level rise, which is not currently part of it.
The researchers found that cracks in the shear margins of the Pine Island Glacier have been documented since 1999 1999 1999. Their satellite imagery shows that the damage dra 2016matically. Has grown dramatically.
Similarly, damage to the Thaiweats Glacier began to increase further in 2016, and fractures began to open rapidly near the glacier’s grounding line, where the iceberg meets the bed.
The researchers warn that the process is creating a reaction loop – where the weakening of the ice is accelerating the damage to the glacier’s weak shear margins, resulting in further damage and breakage of the ice shelf.
Isabella Velegogna, a professor of earth systems science at the University of California, Irvine, who was not involved in the study, said: Will be larger in magnitude, which means that sea levels will rise faster than current estimates. “
There are other processes that play a “huge role” in the evolution of glaciers, such as “the rate of retreat of the grounding line forced by a warm ocean,” Velegogana said.
Glacier in trouble
He said that the ditches hidden under the ice are likely to be the route through which the hot sea water goes to the ground ing under the ice sheet.
Over the past three decades, the rate of ice loss from Thwaites and neighboring glaciers has more than increased fivefold. If the collapse of the thymus were known, it could cause 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 a millimeter to sea level.
Recent findings from Antarctica show that glaciers are “weakening from all angles,” Lermit said.
“The weakest part of this part of Antarctica is coming from below,” he said. “Hot water goes to the base of ocean water (glaciers) and weakens them. What we’ve seen is that it gets so weak, that they get faster and once they get faster. , Then the shear margins become faster and begin to break. “
Valegogna said the discovery “points to the heel of another Achilles system that is suitable for an early return duc, and began with climate change.”
“It seems that the more we look at the evolution of these systems, the more we look at the reasons why they disappear faster than we think,” he said. “We need to act quickly on tackling climate change to secure our future. Now is the time to act.”