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A huge glacier the size of Florida is likely to melt so quickly that it could cause a catastrophic rise in sea level, scientists warned.
While the climate crisis has caused a surge in temperatures and a rapid reduction of ice levels in the Arctic, In Antarctica, it is thought today that much larger layers of ice, containing much more water, are likely to collapse, although they have previously been considered stable.
Thwaites Glacier is one of five recently identified unstable Antarctic glaciers that have doubled their ice loss rate in just six years.
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Covering 70,000 square miles, it is likely to accelerate its flow into the ocean, a new study on the stability of the Antarctic Ice Sheet has suggested.
Once it has crossed a tipping point, it will become an unstoppable process that could raise sea levels much faster than previously expected.Researchers at the Georgia Institute of Technology, NASA Jet Propulsion Laboratory and the University of Washington said after using computer models to predict the effects of glacier instability on ice-breaking velocity.
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A Twin Otter aircraft during a reconnaissance flight over the Antarctic Plateau and Edson Glacier in the Ellsworth Mountains. This utility plane, equipped with wheels or skis, perfectly adapts to the Antarctic environment thanks to its robust construction and its short take-off and landing performances.
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Soldiers move kerosene drums for aircraft during daily maintenance activities
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An explorer points the way forward during a reconnaissance trip on the Edson Glacier in the Ellsworth Mountains. The group moves in a straight line to minimize the risk of falling into a hidden crevasse
EPA
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An INACH member, Pablo Espinoza, rests in his sleeping bag in the Glaciar Union camp. The average temperature inside the tents is minus five degrees Celsius
EPA
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An aerial view of the Glaciar Union camp in the Ellsworth Mountains. The Glaciar Union camp is a Chilean polar station run by the Chilean Antarctic Institute (INACH) and the three groups of the Armed Forces of Chile marking the beginning of all scientific activities planned in Antarctica for the summer season.
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Two nurses treat a wounded soldier in the small hospital at the Glaciar Union camp station. The most common cases are minor work accidents, frostbite and hypothermia.
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A man crosses the settlement of Glaciar Union during a windstorm. Katabatic winds can reach 300 km / h and bring the thermal sensation to dangerous levels
EPA
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Expedition members who have not crossed the Antarctic Circle (a parallel located 66.5 degrees south of the equator) benefit from the "baptism on snow" of other veterans
EPA
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A Chilean air force pilot tries to get a signal on his satellite phone after landing on the Antarctic plateau. Satellite communications are the only way to keep in touch with the main operational base in Punta Arenas.
EPA
10/20
Scientist Ricardo Jana leaves a mobile station for a GPS tracking excursion in the Glaciar Union camp. Localization tools such as the Differential Global Positioning System (DGPS) help improve safety during field trips by locating hidden crevices in a precise manner.
EPA
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A group of explorers extracted blocks of blue ice near the settlement of Glaciar Union. Scientists will use ice to keep their samples in the refrigerator
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An explorer uses a fruit and yoghurt dessert at lunchtime in a common kitchen area in the camp.
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A group of scientists and explorers move to Higgins Nunatak, in the Ellsworth Mountains, on a ski tour. Snowmobiles, ski touring and short flights in Twin Otter aircraft are the most popular travel options for field trips with scientists.
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A man leaves a residential unit buried in the Glaciar Union camp. The accumulation of snow occurs mainly by the movement of the wind rather than by the snow
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Pablo Espinoza gets ready for a field trip in his tent
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Scientists and military play soccer at Glaciar Union camp
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Soldiers shovel dirty snow into an empty drum during a clean-up operation around the camp. Known as the "Chicken Walk", military personnel pick up shovels or hand small debris or small patches of contaminated snow that can be found in the camp area. Shippers want a no-impact stay in this region
EPA
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A group of explorers carries scientists and equipment on snowmobiles during a field trip near Rossman Cove
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An INACH member, René Quinan, in his tent. Up to three people can sleep in these clam tents designed for extreme weather conditions
EPA
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A group of explorers on a reconnaissance trip in ski touring on the Edson Glacier
EPA
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A Twin Otter aircraft during a reconnaissance flight over the Antarctic Plateau and Edson Glacier in the Ellsworth Mountains. This utility plane, equipped with wheels or skis, perfectly adapts to the Antarctic environment thanks to its robust construction and its short take-off and landing performances.
EPA
2/20
Soldiers move kerosene drums for aircraft during daily maintenance activities
EPA
3/20
An explorer points the way forward during a reconnaissance trip on the Edson Glacier in the Ellsworth Mountains. The group moves in a straight line to minimize the risk of falling into a hidden crevasse
EPA
4/20
An INACH member, Pablo Espinoza, rests in his sleeping bag in the Glaciar Union camp. The average temperature inside the tents is minus five degrees Celsius
EPA
5/20
An aerial view of the Glaciar Union camp in the Ellsworth Mountains. The Glaciar Union camp is a Chilean polar station run by the Chilean Antarctic Institute (INACH) and the three groups of the Armed Forces of Chile marking the beginning of all scientific activities planned in Antarctica for the summer season.
EPA
6/20
Two nurses treat a wounded soldier in the small hospital at the Glaciar Union camp station. The most common cases are minor work accidents, frostbite and hypothermia.
EPA
7/20
A man crosses the settlement of Glaciar Union during a windstorm. Katabatic winds can reach 300 km / h and bring the thermal sensation to dangerous levels
EPA
8/20
Expedition members who have not crossed the Antarctic Circle (a parallel located 66.5 degrees south of the equator) benefit from the "baptism on snow" of other veterans
EPA
9/20
A Chilean air force pilot tries to get a signal on his satellite phone after landing on the Antarctic plateau. Satellite communications are the only way to keep in touch with the main operational base in Punta Arenas.
EPA
10/20
Scientist Ricardo Jana leaves a mobile station for a GPS tracking excursion in the Glaciar Union camp. Localization tools such as the Differential Global Positioning System (DGPS) help improve safety during field trips by locating hidden crevices in a precise manner.
EPA
11/20
A group of explorers extracted blocks of blue ice near the settlement of Glaciar Union. Scientists will use ice to keep their samples in the refrigerator
EPA
12/20
An explorer uses a fruit and yoghurt dessert at lunchtime in a common kitchen area in the camp.
EPA
13/20
A group of scientists and explorers move to Higgins Nunatak, in the Ellsworth Mountains, on a ski tour. Snowmobiles, ski touring and short flights in Twin Otter aircraft are the most popular travel options for field trips with scientists.
EPA
14/20
A man leaves a residential unit buried in the Glaciar Union camp. The accumulation of snow occurs mainly by the movement of the wind rather than by the snow
EPA
15/20
Pablo Espinoza gets ready for a field trip in his tent
EPA
16/20
Scientists and military play soccer at Glaciar Union camp
EPA
17/20
Soldiers shovel dirty snow into an empty drum during a clean-up operation around the camp. Known as the "Chicken Walk", military personnel pick up shovels or hand small debris or small patches of contaminated snow that can be found in the camp area. Shippers want a no-impact stay in this region
EPA
18/20
A group of explorers carries scientists and equipment on snowmobiles during a field trip near Rossman Cove
EPA
19/20
An INACH member, René Quinan, in his tent. Up to three people can sleep in these clam tents designed for extreme weather conditions
EPA
20/20
A group of explorers on a reconnaissance trip in ski touring on the Edson Glacier
EPA
All models were pointing towards the glacier, reaching a tipping point and the subsequent collapse of the ice cap, they said.
In the worst case, Thwaites Glacier ice alone could raise sea levels by nearly half a meter (20 inches) in less than 150 years.
The team warned that once the tipping point is reached, even if global temperatures decrease, the flow of the glacier into the sea would already be impossible to stop.
"If you trigger this instability, you do not need to continue forcing the ice cover by raising the temperature. This will continue, and that's the concern, "said the study's chief Alex Robel, Assistant Professor, School of Earth and Atmospheric Sciences, Georgia Tech.
"Climatic variations will always be important after this tipping point, as they will determine the speed at which the ice will move."
NASA scientist Hélène Seroussi added: "After reaching the tipping point, Thwaites Glacier could lose all its ice in 150 years. This would make a sea level rise of about half a meter (1.64 feet). "
By comparison, the current sea level is 20 cm above pre-global warming levels and is the cause of the increase in coastal flooding.
For about 2,000 years until the late 1800s, the world's seas remained almost static, with small fluctuations, but then began to rise, according to the Smithsonian Institution.
The annual rate of sea level rise has almost doubled since 1990.
The extent of instability of the Antarctic Ice Sheet is difficult to study, but computer models predicting its future collapse pose challenges to forecasters and climate modeling teams because they offer a wide range of potential scenarios.
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This is particularly relevant to the challenge of engineering against the dangers of flooding.
"You want to design critical infrastructure to withstand the upper limit of potential sea-level scenarios in a hundred years," said Dr. Robel. "It can mean building your water treatment plants and your nuclear reactors in the worst case, which could be a sea level rise in Thwaites Glacier alone, which is a huge difference."
The Antarctic contains large amounts of ice – about 90% of the world's ice – and unlike the Arctic, most of the ice is out of the water and on land. The average thickness of the ice is 1.6 miles deep. At its thickest point, the layer of ice is almost three miles deep.
As a result, the collapse of its ice caps presents more serious scenarios for sea level rise. While in the Arctic, 90% of the iceberg's mass is already under water. When the ice melts, the volume decreases, resulting in little change in sea level.
Instability under the Thwaites Glacier would be related to the topography of the ice and sea meet zone.
The "grounding line", where the bottom of the ice cap rests on the bottom of the sea, can retreat under the glacier due to warming ocean waters that are digging ice.
In deeper areas, ice above the sea floor can move faster because the water gives it more lift, which can accelerate the movement of the glacier.
"Once the ice has passed over the ground line and a little above the water, it contributes to the sea level because the buoyancy holds it more than it was before" , said Dr. Robel. "The ice pours on the floating ice floe and melts or breaks into an iceberg."
Dr. Seroussi added, "The process becomes self-perpetuating."
The study is published in Proceedings of the National Academy of Sciences.
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