Why is the Thwaites Glacier so famous ?
Thwaites Glacier is a glacier in West Antarctica known for its rapid
Together with the Pine Island Glacier, the Thwaites Glacier has been described as part of the "weak underbelly" of the West Antarctic Ice Sheet.
Thwaites Glacier is a huge Antarctic colossus,which is rapidly melting, dumping billions of tons of ice into the ocean every year and raising the level of the world's oceans. Thwaite's size and rate of melting has led to it being dubbed the "doomsday glacier."
What is glacier retreat and why is it so dangerous?
Scientists evaluating the state of the planet, eachday find undeniable evidence that the Earth is warming up, in some places it happens very quickly. Most believe that human activities, in particular the burning of fossil fuels and the associated accumulation of greenhouse gases in the atmosphere, have influenced the warming trend. Over the past decade, scientists have recorded record high average annual surface temperatures and observed other signs of change across the planet: in the distribution of ice, as well as salinity, levels and temperature of the oceans.
Main figures
- Ice is changing throughout the Earth. Since 1912, Kilimanjaro's famous snows have melted by over 80%. The glaciers in the Himalayas are retreating so quickly that researchers think that most of the glaciers in the central and eastern part of this mountain range could practically disappear by 2035.
- Arctic sea ice has thinned significantly overthe past half century, and its scale has declined by about 10% over the past 30 years. Repeated readings of NASA's laser altimeter show the edges of the Greenland ice sheet are shrinking. Spring breakup of freshwater ice in the Northern Hemisphere is already nine days earlier than it was 150 years ago, and autumn ice formation is ten days later.
- As a result of the melting permafrost in parts of Alaska, the ground has sunk more than 15 feet (4.6 meters). From the Arctic to Peru, from Switzerland to the equatorial glaciers of Man Jaya in Indonesia.
When the temperature rises and the ice melts, morewater flows into the seas from glaciers and ice caps, and ocean water heats up and expands. According to the Intergovernmental Panel on Climate Change (IPCC), this combination of effects has played a major role in the rise in global mean sea level by four to eight inches (10 to 20 cm) over the past 100 years.
Scientists find record high water temperature in Antarctica
Scientists note that sea level is significantlyincreased and decreased over 4.6 billion years of Earth's history. But the recent rate of global sea level rise has deviated from the average rate of the past two to three thousand years and is rising more rapidly. If this trend continues or accelerates, it could cause dramatic changes on the world's coastlines.
Written by Myrna H.P.Hall and Daniel B.2003 Fagre - USGS: , Public domain
What did the scientists find out?
Recently British-American group of scientistssurveyed the deep seabed channels in front of the glacier, which are responsible for the penetration of warm water access to the lower Thwaite. The new information will be used to try to predict the future of the ice stream.
Previously, these channels were not mapped withthe kind of detail that is available now. As a result, scientists have found that the channels through which warm water flows to the glacier and destroys it, in fact, are much larger than anyone thought - up to 600 meters deep. Dr. Kelly Hogan of the British Antarctic Survey (BAS) suggests thinking about six football pitches in a row to assess the scale of the problem.
“Because they are so deep and so wide,this allows much more water to enter and melt Thwaites' floating front, as well as its ice resting on the seabed, ”Kogan explained in an interview with BBC News.
Why is the Thwaites Glacier so important?
West of the Antarctic continent,Thwaites Glacier is similar to the UK in size. Its moving front, or "ice shelf", goes far out to sea and throws huge icebergs into the ocean. Satellite monitoring shows that this glacier is melting faster and faster.
In the 1990s, he lost just over 10 billion tonsice per year. Today it is more than 80 billion tons. The melting is believed to be due to the influx of relatively warm bottom water from the wider ocean. Currently, ice loss at Thwaites accounts for approximately 4% of the annual rise in sea level, with the potential for an increase of 65 cm if the entire glacier collapsed.
Yes, this will happen in the short term andmedium term, but the Thwaites Glacier is considered particularly vulnerable to global warming, and scientists would like to know exactly how quickly any change can occur.
What does the latest research show?
In 2019, the UK and the US merged theirefforts to clarify the situation with the Thwaites Glacier. Scientists from both countries sent a ship equipped with an echo sounder straight to the icy cliffs to trace the shape of the seabed below.
In addition, an airplane joined the expedition, which provided scientists with data on small changes in gravity. The deviations in the calculations reflected the unevenness of the seabed under the shelf.
Thwaites Glacier. Author: NASA, Public Domain
Taken together, the two datasets gave scientiststhe best view of the topography of the Thwaites Glacier. The details of the deep channel network that traverse the ridge before joining to form a large cavity under the ice shelf have become easier to understand.
Related channels, which scientists first detailedmapped are potential pathways for deep-sea warm water to penetrate and cause damage to the glacier at the point where it still rests on the seabed. Because of these processes, he will begin to rise and swim, explains Dr. Tom Jordan from BAS. The melting of the base of the ice shelf will force the ice to move faster with the current, collide more with warm water, collapse, melt and, accordingly, raise the level of the World Ocean even higher. A network of underwater canals made the glacier even more dangerous than scientists thought.
How the new data will be used lFor example, if you want to"Doomsday "?
Scientists need real-world data tomodeling the possible future of the planet, they obtained realistic results. The new information clarifies the volumes of warm water penetration that are important in various scenarios of sea level rise.
Now, after conducting research, scientists have a better understanding of the overall unevenness of the seafloor.This tells us about the speeds that ice can reach deep in the glacier when it slideson rocks and deposits.
What could happen in the near future?
At the moment, the eastern side of the shelfthe glacier is hooked onto a large ridge, which gives it stability. But the current melting trend suggests that this situation will not last long, said Dr. Robert Larter of BAS.
As the Eastern Ice Shelf detaches, the ice will expand and thin, eventually breaking up, as we see now happeningEven before the ice shelf splits, detachment and thinning will reducethe supporting effect of the ice shelf on the glacier upstream, resulting inThis, in turn, will further accelerate the flow of ice.thinning of the glacier and retreat of the grounding line.
Dr Robert Larter of BAS for the BBC
At the moment, British and American scientists have had to temporarily suspend their research in the Thwaites Glacier due to the COVID-19 pandemic.
This summer the teams were supposed to return toglacier, but the remoteness of this place poses too great a risk in case anyone falls ill. However, once the coronavirus outbreak is properly contained, scientists will return.
“It's amazing to visit a place like a glacierThwaites, and see the changes taking place right before your eyes, ”emphasizes Dr. Hogan. - When we were there in 2019, we were able to get right to the rocks of the ice shelf, and the reason we could do this and make our observations was that icebergs and sea ice, which have always been here historically, are starting to disappear ".
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