Greenland is in the midst of an unexpected early ice melt due to geothermal heat, a new study has found.
More specifically, the heat deep within Earth boosts the fast ice flow and melting of glaciers in the country. In fact, approximately 50 percent of area covered in ice in North-Central Greenland now rests on a defrosted bed. The resulting water is directed toward the ocean via a dense water system underneath the ice.
"The strength of this paper is that many different lines of reasoning about data lead to the same conclusion," says study author Jesse Johnson from the University of Montana.
Johnson adds that the study was able to show that it would be almost impossible to explain ice velocities through satellites without factoring in the effects of geothermal heat.
Although the anomaly has long been suspected by experts, Johnson's research was able to quantify the area and extent, as well as why it exists.
Heat From Down Under
Geological marks of history still lurk somewhere within the ice sheet of Greenland. These are manifested by areas of intense geothermal heat that cause the ice to melt and flow swiftly.
The anomaly, according to Johnson, presents observations from both drilling and radar data of widespread melting underneath the sheet. It also explains the additional sliding at the bottom part of the ice that rapidly flow over a distance of about 750 kilometers (466 miles) from the summit of the ice sheet to the North Atlantic ocean.
About 35 million to 85 million years ago, the tectonic activity at the North Atlantic ocean moved Greenland to an area where there is an abnormally hot mantle. This mantle increased the temperature and cut the crust of Greenland, resulting in geothermal anomaly.
Now, this event led to the situation of today's hydrological status in the area. Specifically, it caused the increased melting and rapid flow of water - factors which should be included in further studies.
Modernity Saves The Day
Despite the ancient nature of the anomaly, modernity saved the day. Using a combination of satellite data, computer models and airborne data, the secrets of Greenland's history were revealed.
The area and orientation of the geothermal heat flow conform to the direction where Greenland moved.
The association between the geothermal heat and ice flow dynamics was quite unexpected, says Johnson. It exhibits that the control really evolved through time, the same as evolution of Earth's mantle and tectonic plates.
The study appears in the April 2016 issue of Nature Geoscience.