A study published in the journal Nature has found that not only is the upwelling of warm water carving cavities into the marine extension of Thwaites Glacier which is causing the front of the ice platform to crumble into the Amundsen Sea Embayment; it is also vulnerable to a geothermal heat flow (GHF) beneath the ice of not only Thwaites but Pine Island Glacier and Pope Glaciers which drain West Antarctic Ice Sheet. The glaciers account for 36% of the total Antarctic ice mass loss over the past four decades.
The West Antarctic Rift System underlies the Amundson Sea, the Ross Sea, and the Bellingshausen Sea. This tectonic setting favors high geothermal flow, say the study authors.
Brandon Specktor does an excellent job deciphering the study. He writes In Live Science:
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.
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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.
"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.
A Stratospheric Warming event over Antarctica aggravated a drought in Australia in 2019. The continent had a horrific wildfire season in 2019 and 2020.
Very rare Sudden Stratospheric Warming (SSW) event continues unfolding above the South Pole.
This SSW could go down in history as the strongest warming event on record, NIWA said, adding there is increased risk for southerlies in New Zealand into October.
SSW events are rare in the southern hemisphere, with only two in New Zealand in recorded times - one in September 2002 and the other in September 2010
"Although we have seen plenty of weak or moderate variations in the polar vortex over the past 60 years, the only other true sudden stratospheric warming event in the Southern Hemisphere was in September 2002," BOM meteorologists said.
"Impacts from this stratospheric warming are likely to reach Earth’s surface in the next month and possibly extend through to January. Apart from warming the Antarctic region, the most notable effect will be a shift of the Southern Ocean westerly winds towards the Equator.
"For regions directly in the path of the strongest westerlies, which includes western Tasmania, New Zealand’s South Island, and Patagonia in South America, this generally results in more storminess and rainfall, and colder temperatures. But for subtropical Australia, which largely sits north of the main belt of westerlies, the shift results in reduced rainfall, clearer skies, and warmer temperatures.
"Past stratospheric warming events and associated wind changes have had their strongest effects in NSW and southern Queensland, where springtime temperatures increased, rainfall decreased and heatwaves and fire risk rose."