The so-called "Doomsday Glacier" in Antarctica is losing ice faster than any other time in the preceding 5,500 years

The rate at which the melting ice increased the Antarctic shorelines was revealed by ancient bones.

 

The so-called Doomsday Glacier in Antarctica is shedding ice faster than it has in the past 5,500 years. This has raised fears about the future of the ice sheet and the potential for catastrophic sea level rise caused by the melting ice on the frozen continent.

 

A study of prehistoric sea deposits found on the coasts around the "doomsday" Thwaites Glacier and the adjoining Pine Island Glacier, both located on the West Antarctic Ice Sheet, led to the discovery. Both glaciers are known as "doomsday glaciers." What is this bone-chilling news? According to a report published on June 9 in the journal Nature Geoscience, researchers found that the rate at which glaciers in Antarctica are melting is accelerating at a rate that is quicker than at any other time in recorded history.

 

According to co-author Dylan Rood, an Earth scientist at Imperial College London, "these currently elevated rates of ice melting may signal that those vital arteries from the heart of the West Antarctic Ice Sheet have been ruptured, leading to accelerating flow into the ocean that is potentially disastrous for future global sea level in a warming world." This was said in a statement. "These currently elevated rates of ice melting may signal that those vital arteries from the heart of the West Antarctic Ice Sheet have been ruptured."

 

"Can we put a halt to the bleeding at this point?" Rood asked.

 

The term "Doomsday Glacier" was given to Thwaites because it is one of Antarctica's glaciers melting the quickest. Since the 1980s, Thwaites has been losing ice at an estimated rate of 595 billion tons (540 billion tons metric), which has contributed to an increase of 4% in the average level of the world's oceans. Both the Thwaites Glacier and its neighbor to the north, the Pine Island Glacier, cover enormous expanses; the Thwaites has a surface area of approximately 74,130 square miles (192,000 square kilometers), which makes it nearly as big as Great Britain, and the Pine Island has a surface area of 62,660 square miles (170,000 square kilometers) (162,300 square km).

 

Both glaciers have undersides exposed to currents of warm, thick, salty water because the sea-facing extremities of the glaciers are situated above a bowl-like ocean basin. This causes the bottoms of the glaciers to melt more quickly. This warm water is not only melting the glaciers where they extend into the Amundsen Sea but also chipping away at them from beneath, releasing them from their primary anchoring points, located to the north. In addition, the subglacial melting weakens the glaciers and makes them more prone to surface cracks. These surface fissures have the potential to spread throughout the entire ice sheet, which might lead to the sheet breaking up entirely. If the whole West Antarctic Ice Sheet were to break up and melt into the sea, it would add around 11 feet to the level of seawater worldwide (3.4 meters).

 

The scientists searched for hints on Antarctic beaches near the point where the glaciers met the water to compare the glaciers' rates of melting in the recent past and those in the distant past. Because ice presses down on the ground, at the end of the most recent ice age (about 11,500 years ago), when some of that frozen weight melted and drained into the sea, the Earth rebounded, revealing shorelines that were previously buried beneath the waves. The researchers thought that by determining the ages and heights of roughly two dozen different shorelines, they would be able to determine how rapidly the ice receded from the land before it began to advance once more.

 

Before using radiocarbon dating to determine the ages of the ancient biomatter, the researchers assessed the ages of the shorelines by collecting old shells and small fragments of penguin bones and then examining the ancient biomatter. Carbon-14 is a radioactive carbon isotope, or a variant with a different number of neutrons found everywhere on Earth and quickly absorbed by plants and animals. This method determines the age of organic material by measuring the amount of carbon-14 in the material. Carbon-14 is a radioactive carbon isotope. When animals pass away, they stop absorbing carbon-14 in their tissues, and the amount they have already absorbed begins to degrade. This process co-occurs with the cessation of carbon-14 absorption. Scientists can determine the ages of creatures that passed away thousands of years ago by measuring the quantities of undecayed carbon-14 in the remains of the animals. The half-life of carbon-14 is 5,730 years, which is the amount of time it takes for half of carbon-14 to decay.

 

Following radiocarbon dating of penguin bones and shells collected from over 20 distinct beaches, the researchers discovered that the formation of the beach with the most extended history and the highest elevation began approximately 5,500 years ago. According to the findings of the researchers, the pace of ice melting along the shorelines was about 0.14 inches (3.5 millimeters) each year from that point until approximately 30 years ago. On the other hand, the rate of coastal advance has soared over the past three decades, reaching up to 1.6 inches (40 mm) every year.

 

According to Rood, "even though these fragile glaciers have been relatively steady throughout the last few millennia, their current rate of retreat is quickening and is already affecting global sea levels."

 

It is currently unknown what this will mean for Antarctica's glaciers, ice sheets, and other susceptible coasts worldwide. Although the researchers' findings are worrying, they do not answer the question of how many times the glaciers may have receded and then advanced throughout recorded history. The researchers intend to drill through the ice to collect rock samples from the landmass beneath it. This will allow them to determine whether or not the current rate of melting is reversible or whether or not the glaciers have genuinely reached a point where there is no turning back.

Article source : https://www.livescience.com/penguin-bones-reveal-secrets-of-ddomsday-glacier

Image source  : https://pixabay.com/id/vectors/gunung-garis-besar-biru-gletser-305724/

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