Antarctica: an expedition to search for Endurance, Ernest Shackleton's ship
Antarctica
On November 21, 1915, a three-mast sank in the waters of the Weddell Sea, crushed by the polar ice. An expedition to find it is underway
(Photo: Frank Hurley - Digital Collections of the National Library of Australia) Weddell Sea, Southern Hemisphere, 21 November 1915. The ship Endurance, commanded by Captain Ernest Shackleton, sinks into the waters freezing after being crushed by the Antarctic ice. In the intentions of the commander, it would have had to arrive on the polar ice pack, a hundred kilometers further south, where the men of the crew would have landed to attempt the last great feat of the so-called heroic era of the Antarctic expeditions: after reaching the South Pole from part of Amundsen first and of Scott a few days later, only the crossing from part to part of the continent remained to be made, for a total of almost 3 thousand kilometers. But the Endurance did not make it, and the mission failed even before starting: Shackleton, with a heroic feat, still managed to rescue all his men, sailing for thousands of kilometers with a lifeboat to reach Georgia. of the South. Today, finally, a team of scientists announced the start of an expedition to find the wreck of the Endurance, buried for over a century in the icy waters of the Southern Ocean.The expedition, Endurance22, should start in February 2022, scanning the ocean floor with radar, sonar and submarine drones to look for traces of the wreck. If they find it, they will film and study it without manipulating it in any way, since it is protected by the International Antarctic Treaty. This is not the first expedition to attempt the enterprise: in fact, already in 2019, the same team had tried to locate the Endurance, then renounced the mission due to too hostile weather conditions and the loss of a submarine.
“Trying to locate the wreck of the Endurance,” explained Mensun Bound, director of Endurance22, “a feat that has long been considered impossible, is a project with extremely exciting prospects. Given the complexity of the Antarctic environment, there are no guarantees of success, but we will be inspired by the great Antarctic explorers and embark on the Endurance22 with high hopes. With the best possible technology and an excellent exploration team we hope and pray to be able to accomplish a historic feat in polar history ".
The Endurance is supposed to be under 3,000 meters of water, and the hope is that the absence of light and the low oxygen content have preserved the planking; the greatest difficulty of the mission, experts say, will lie in demolishing and breaking through the blocks of ice of the Weddell Sea. "We hope to be able to unearth the wreck", hopes Donald Lamont, president of the Falklands Maritime Heritage Trust, financier of the mission, "and that this undertaking will inspire new generations to explore, overcome challenges and better understand the Antarctic environment ”.
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Antarctica's 'Doomsday Glacier' is fighting an invisible battle against the inner Earth, new study finds
West Antarctica is one of the fastest-warming regions on Earth. For evidence, you need look no further than Thwaites Glacier — also known as the 'Doomsday Glacier.'
Since the 1980s, Thwaites has lost an estimated 595 billion tons (540 billion metric tons) of ice, single-handedly contributing 4% to the annual global sea-level rise during that time, Live Science previously reported. The glacier's rate of ice loss has accelerated substantially in the past three decades, partially due to hidden rivers of comparatively warm seawater slicing across the glacier's underbelly, as well as unmitigated climate change warming the air and the ocean.
Now, new research suggests that the warming ocean and atmosphere aren't the only factors pushing Thwaites to the brink; the heat of the Earth itself may also be giving West Antarctica's glaciers a disproportionately nasty kick.
In a study published Aug. 18 in the journal Communications Earth & Environment, researchers analyzed geomagnetic field data from West Antarctica to create new maps of geothermal heat flow in the region — essentially, maps showing how much heat from Earth's interior is rising up to warm the South Pole.
The researchers found that the crust beneath West Antarctica is considerably thinner than in East Antarctica — roughly 10 to 15 miles (17 to 25 kilometers) thick in the West compared with about 25 miles (40 km) thick in the East — exposing Thwaites Glacier to considerably more geothermal heat than glaciers on the other side of the continent.
'Our measurements show that where the Earth's crust is only 17 to 25 kilometers thick, geothermal heat flow of up to 150 milliwatts per square meter can occur beneath Thwaites Glacier,' lead study author Ricarda Dziadek, a geophysicist at the Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research in Germany, said in a statement.
Because West Antarctica sits in an oceanic trench, the crust beneath the seabed is much thinner than the crust below East Antarctica. Scientists have long suspected that this comparatively thin crust must be absorbing more heat from the planet's upper mantle (which experiences average temperatures of 392 degrees Fahrenheit, or 200 degrees Celsius), impacting the formation and evolution of glaciers there over millions of years.
In the new study, the researchers quantified that difference in heat flow for the first time. Using a variety of magnetic field datasets, the team calculated the distance between the crust and the mantle at various spots throughout Antarctica, as well as the relative heat flow in those areas.
It's hard to tell exactly how warm the glacier is where the ice meets the seabed, as different types of rock conduct heat differently — however, the researchers said, it's clear that this extra supply of heat in the West can only mean bad news for Thwaites.
'Large amounts of geothermal heat can, for example, lead to the bottom of the glacier bed no longer freezing completely or to a constant film of water forming on its surface,' study co-author Karsten Gohl, also a geologist at AWI, said in the statement. Either of these conditions could cause the glacier's ice to slide more easily over the ground, causing the glacier's ice loss to 'accelerate considerably,' Gohl added.
A scenario like that could put the Doomsday Glacier's name to the test; if Thwaites Glacier were to entirely collapse into the ocean, global sea levels would rise by about 25 inches (65 centimeters), devastating coastline communities around the world, Live Science previously reported. What's more, without the glacier plugging the edge of the West Antarctic Ice Sheet like a cork in a bottle of wine, ice loss could accelerate dramatically in the entire region, leading to unprecedented levels of sea level rise.
Researchers will soon have a chance to further hone their measurements of the heat flow below Antarctica. A major international research project is currently underway at the South Pole, including missions to drill ice cores that stretch down to the bed of Thwaites Glacier. Heat flow measurements from these core samples could give scientists a better idea of how much time is left on the Doomsday Glacier's ticking clock.
Originally published on Live Science.
