Researchers at the University of Aarhus in Denmark have found an explanation for the melting process of the Greenland ice sheet, which looks anomalous compared to other parts of the ice sheet in the world. According to scientists, they received data confirming the hypothesis that the decrease in the mass of Greenland's glaciers is affected not only by climate change, but also by the internal processes taking place in the bowels of the planet itself. The study was published in the British scientific journal Nature.
For 10 years, scientists measured temperature and salt content in two places on the island: in one of the fjords near Daneborg station in northeastern Greenland, where there are many geothermal springs, and south of a rapidly melting glacier located just north. Based on the data, the researchers calculated that the amount of deep Earth heat that is released in this area can be compared with the operation of a giant heater, which would be located inside a glacier and powered by a 2 MW generator.
The exact amount of thermal energy released under the entire Greenland ice sheet as a result of such geothermal activity is difficult to calculate, scientists admit. However, they are confident that it is enough to gradually melt the lower layers of glaciers, which because of this begin to slide into the sea at a much faster rate than before.
"There is no doubt that the Earth's deep heat affects the movement of the ice sheet," explains study leader Søren Ryusgard. "We think that the same processes of release of thermal energy from the bowels of the Earth occur under most of the entire ice sheet in northeastern Greenland."
According to scientists, geothermal activity, accompanied by the release of thermal energy, occurs on the entire surface of the Earth, and this process is associated with the peculiarities of the development of the planet in the early period of its formation in the solar system. However, deep-seated heat sources are unevenly distributed over the surface. For example, Iceland, neighboring to Greenland, is currently a very active such site.
According to earlier findings of an international group of researchers led by Associate Professor of Copenhagen University Shfakat Abbas Khan, published in 2016, since the last glacial maximum (about 23 thousand years ago) Greenland has lost almost 40% of its ice, due to which the level of the World Ocean has risen by 4.6 meters. If all the glaciers of the island that exist today are melted, then the level of the World Ocean will rise by another 7.5 meters. And although this is still a long way off, according to estimates by the UN-established Intergovernmental Panel on Climate Change, by the end of the 21st century, due to the melting of polar ice caps, the level of the World Ocean may rise by 1 meter.