Until Recently Scientists Believed Climate Change Has Been Melting Antarctic Glaciers. Now They Do Not.

According to a new study, 36% of 1979-2017 Antarctic ice loss was from the Thwaites and Pine Island glaciers. Scientists believed this glacier melt was due to anthropogenic climate change “until recently”. Now they say the glacier mass losses are due to the thin underlying crust and anomalously high geothermal heat in this region.

We’ve recently learned that “profound” cooling has been occurring for East Antarctica since the 1970s, and cooling (-1.68°C since 1979) has also extended to West Antarctica.

Another new study indicates Antarctica contributed just 0.76 of a centimeter to sea level rise from 1992-2017, or 0.3 of a millimeter per year. Also, comparing 1997-2008 to 2009-2018, there has been a net advance in the ice extent for Antarctica during 2009-2018.

“Until recently, experts attributed these changes to climate change”

The profound ice loss from West Antarctica’s Thwaites Glacier has by itself been responsible for about four percent of the global sea level rise in recent decades.

Possibly due to allegiance to “consensus” statements about anthropogenic global warming, it was still common for scientists to believe this glacier melt was due to the “warming” in Western Antarctica (that, as noted above, curiously has disguised itself as cooling since 1979).

But a new study and its AAAS/Science press release throw more cold water on the notion that humans are driving ice melt trends in Antarctica, as “there is a conspicuously large amount of heat from Earth’s interior beneath the ice” in the very locations where the ice melt is most pronounced.

Image Source: AAAS

The direct transfer of heat can facilitate basal melting and control ice rheology and basal sliding

While the Earth’s crust has an average thickness of about 40 km, in the region of the Thwaites, Pine Island, and Pope Glaciers, the anomalously thinner crust (10 to 18 km) exposes the base of this regional ice to 580°C tectonic trenches.

The “elevated geothermal heat flow band is interpreted as caused by an anomalously thin crust underlain by a hot mantle,” which is exerting a “profound influence on the flow dynamics of the Western Antarctic Ice Sheet.”

Image Source: (Dziadek et al., 2021)

via NoTricksZone

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September 6, 2021 at 11:56AM

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