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Where is Antarctic is one of the fastest warming regions on Earth. For proof, you don’t need to look any further than Thwaites Glacier, also known as “Doomsday Glacier”.
Since the 1980s, Thwaites has lost an estimated 595 billion tonnes (540 billion metric tonnes) of ice, alone contributing 4% of the annual global sea level rise during this period, Previously reported live science. The rate of ice loss from the glacier has accelerated dramatically over the past three decades, in part due to the hidden rivers of relatively warm seawater that flow through the belly of the glacier, as well as climate change warm 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 warmth of Earth itself can also disproportionately kick West Antarctic glaciers.
In a study published Aug. 18 in the journal Earth & Environment Communications, the researchers analyzed data from the West Antarctic geomagnetic field to create new maps of the geothermal heat flow in the region – essentially, maps showing the amount of heat coming from Inside the Earth rises to warm the South Pole.
Researchers have found that the crust under West Antarctica is considerably thinner than in East Antarctica – about 10 to 15 miles (17 to 25 kilometers) thick in the west compared to about 25 miles (40 km) d thickness in the east – exposing the Thwaites Glacier to much more geothermal heat than glaciers across the continent.
“Our measurements show that where the earth’s crust is only 17 to 25 kilometers thick, a geothermal heat flux of up to 150 milliwatts per square meter can occur under the Thwaites Glacier,” said Ricarda Dziadek, lead author of the study, geophysicist at the Alfred Wegener Institute (AWI), Helmholtz Center for Polar and Marine Research in Germany, said in a press release.
Because West Antarctica sits in an ocean trench, the crust below the seabed is much thinner than the crust below East Antarctica. Scientists have long suspected that this relatively thin crust must absorb more heat from the planet’s upper mantle (which experiences average temperatures of 392 degrees Fahrenheit, or 200 degrees Celsius), which has an impact on formation and evolution. glaciers over millions of years.
In the new study, researchers quantified this difference in heat flow for the first time. Using various magnetic field data sets, the team calculated the distance between the crust and the mantle at various locations in Antarctica, as well as the relative heat flux in those areas.
It’s hard to say exactly how hot the glacier is where the ice meets the seabed, as different types of rocks conduct heat differently. .
“Large amounts of geothermal heat can, for example, cause the bottom of the glacier bed to no longer freeze completely or a constant water film to form on its surface,” said the co-author of the study, Karsten Gohl, also a geologist at AWI. in the statement. Either of these conditions could cause glacier ice to slide more easily across the ground, resulting in “the loss of ice from the glacier dramatically accelerating,” Gohl added.
A scenario like this could put the name of Doomsday Glacier to the test; if the Thwaites Glacier collapsed entirely into the ocean, global sea level would rise by about 25 inches (65 centimeters), devastating coastal communities around the world, Previously reported live science. Additionally, without the glacier plugging the edge of the West Antarctic ice sheet like a cork in a wine bottle, the loss of ice could dramatically accelerate across the region, causing the sea level to rise. unprecedented sea.
Researchers will soon have the opportunity to refine their measurements of heat flux under Antarctica. A major international research project is currently underway at the South Pole, including ice core drilling missions that extend to the bed of the Thwaites Glacier. Measurements of the heat flux from these cores could give scientists a better idea of how much time is left on the Doomsday Glacier clock.
Originally posted on Live Science.
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