Photo: Alexander Kovalev / RIA Novosti
Scientists at the Institute for polar and marine research Alfred Wegener (Germany) came to the conclusion that the melting of the permafrost on the coast of the Okhotsk sea intensifies the greenhouse effect and global warming. About it reported in a press release on EurekAlert!.
The researchers analyzed marine sediments along the coast of the Okhotsk sea, the age of which reached 11.5, 14.6 and 16.5 thousand years ago. It is known that in those days, coinciding with the end of the last era of glaciation, there was a sudden jump in the concentration of carbon dioxide in the Earth’s atmosphere, but their cause remained unknown.
It turned out that the sediments contain plant remains that have sunk to the seabed. Organic mass was several thousand years older than the surrounding rocks, indicating that they were released by the melting permafrost and into rivers. Approximately 11.5 and 14.6 thousand years ago, when there was intense melting of glaciers, sea level rose about 20 meters in a few centuries. This, in turn, has led to a significant erosion of coastal permafrost in the sea of Okhotsk and the North Pacific ocean.
However, the melting permafrost has also led to the enhanced greenhouse effect due to release of a large amount of carbon dioxide. Carbon dioxide is formed in the permafrost zone because of decomposition by bacteria a large amount of biomass (mainly crop residues) contained in the frozen ground. Computer simulation results confirmed that erosion contributed to increasing levels of greenhouse gases in the atmosphere for 50 percent of the 11-14 thousand years ago and 25 percent to 16 thousand years ago.
According to scientists, at present the same scenario again. The coast in the Arctic are intensively destroyed, and in some areas the coastline recedes with a speed of 20 meters per year. However, until now the effect of erosion of the permafrost in climate models had been underestimated.
Video, photo All from Russia.