Greenland is shedding ice like a popsicle on defrost. And some of Greenland’s fast-flowing glaciers feel the burn of a heat source that hails from Earth’s deep interior. A new study is among the first direct measurements of geothermal heat flux in Greenland. This heat source – enough power to light up roughly 1,600 American homes – lubricates the base of overlying glaciers, accelerating their journey toward the sea.
The new study was motivated by unusually high temperature readings observed at the bottom of the Young Sound fjord, a 56-mile-long fjord in northeast Greenland, in 2005. The researchers took temperature measurements in the deepest part of the fjord for the next ten years, and used them to estimate a geothermal heat flux of roughly 100 mW per square meter.
Combining the new measurements with other sites of reported geothermal activity around Greenland clearly shows that East Greenland is a hotspot. The findings are consistent with other work suggesting geothermal heat may be part of the reason the nearby Northeast ice stream – a 100-mile-long ice flow that drains into several massive coastal glaciers – is moving so fast.
It’s well known that Greenland contains enough ice to raise sea levels by nearly 25 feet were it all to melt. And melting may occur faster than we thought as the Earth warms, because of how Greenland’s glaciers are anchored to bedrock.
Geothermal heat is very important in Greenland, and we know very little about it. The uncertainty is close to 100 percent.