Researchers have acquired evidence that heat emanating from deep below the Earth’s surface is contributing to the meltdown of Greenland’s glaciers. Though they have long suspected that a subterranean heat source was a factor in the melting glaciers, scientists were previously unable to determine the precise mechanism by which this occurred. Data gathered from Greenland’s Young Sound fjord region, a geologically active area featuring many hot springs in which temperatures can reach 140 degrees Fahrenheit, indicates that radiant heat loss is melting glaciers from the bottom up. This discovery will allow researchers to more accurately assess the stability of Greenland’s ice sheet and better predict sea level rise.
The heat rising from below Greenland’s surface has loosened the lowest levels of glaciers, easing their slide into the sea. “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 northeastern corner of Greenland,” wrote Søren Rysgaard, lead author of the study published in Scientific Reports. The heat source is known as a geothermal heat flux, an ancient phenomenon found throughout the planet. In Greenland, the heat percolates from below the surface up through fjords, warming deep sea temperatures that then transfer this heat to the surrounding glaciers.
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Because geothermal heat fluxes are difficult to assess, “our results are very unique because we determined the relatively small heat flux from a decade-long warming of an almost stagnant water mass,” co-author Jørgen Bendtsen told Newsweek. Earth’s heat circulating up through the fjords of Greenland is one of several factors contributing to the melting glaciers. Rising air and sea temperature, precipitation, and the unique qualities of the ice sheet also affect the speed of glacier melting.
Images via Wieter Boone, Mikael Sejr, and Søren Rysgaard