New research suggests the dissipation of heat from Earth's interior is responsible for the acceleration of the seaward slide of Greenland's ice sheets.
The descent of Greenland's shrinking glaciers is well documented, but the latest research -- published this week in the journal Scientific Reports -- is the first to link the ice loss with escaped heat from Earth's interior.
The research was made possible by a decade-long survey of Greenland's Young Sound fjord. For ten years, scientists with the Arctic Research Centre, Aarhus University and the Greenland Institute of Natural Resources measured temperatures and salinity levels in the fjord. Their survey showed deep-lying water in the fjord, between 650 and 1,100 feet deep, has gradually warmed over the last decade.
Further analysis showed a significant amount of heat is emanating from Earth's interior, slowly warming the fjord's water. Scientists estimated 100 megawatts per square meter of energy was transferred from the Earth's interior to the fjord.
The findings suggest similar amounts of heat were transferred to the bottoms of surrounding glaciers. This newly detailed warming mechanism creates lubrication, accelerating glacial descent.
"It is a combination of higher temperatures in the air and the sea, precipitation from above, local dynamics of the ice sheet and heat loss from the Earth's interior that determines the mass loss from the Greenland ice sheet," researcher Soren Rysgaard said in a news release. "There is no doubt that the heat from the Earth's interior affects the movement of the ice, and we expect that a similar heat seepage takes place below a major part of the ice cap in the north-eastern corner of Greenland."
Measuring heat flux beneath glaciers is difficult, but scientists hope their latest findings will lead to more accurate modeling of the warming mechanism. With more accurate measurements of heat flux, scientists can more accurately predict the fate of Greenland's ice sheets.
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Michael J. Sloboda:
Posted: 2018-01-23 @ 3:57pm PT
100 megawatts per square meter or square kilometer?