Greenland has been sitting over a particularly hot mantle of the Earth’s crust, which a new study says is melting the base of the world’s second-largest ice sheet.
Between 80 million and 35 million years ago, Greenland moved over an area of “anomalously high geothermal flux,” according to scientists at the German Research Centre for Geosciences. The study’s authors “suggest that this anomaly explains the observed melting of the ice sheet’s base, which drives the vigorous subglacial hydrology and controls the position of the head of the enigmatic 750-km-long northeastern Greenland ice stream.”
“The geothermal anomaly which resulted from the Icelandic mantle-plume tens of millions of years ago is an important motor for today’s hydrology under the ice sheet and for the high flow-rate of the ice,” geoscientist Irina Rogozhina, one of the study’s authors, said in a statement.
Rogozhina and her colleagues used “independent seismic, gravity and tectonic data” to show how Greenland moved over the “Iceland mantle plume” between 80 and 35 million years ago. Researchers contend their study adds to the debate surrounding Greenland’s future at a time when scientists are fretting that man-made global warming will cause massive amounts of ice melt.
“This, in turn, broadly influences the dynamic behavior of ice masses and must be included in studies of the future response to climate change,” Rogozhina said.
The study, linking melting at the base of Greenland’s ice sheet to geothermal activity, comes as scientists worry Greenland could melt faster than originally predicted. These worries were spurred by a recent study claiming Antarctica could melt faster than scientists thought — a report based on overheated climate models.