Scientists of the Institute of Ecology NSU HSE determined the cause of the melting of underwater permafrost in the area of the East Siberian Arctic shelf. According to the results of the study published in the MARINE AND PETROLEUM GEOLOGY journal, not only the increase in sea water temperature, but also migration of salts ions, such as NaCl plays a key role. This is reported in a press release of HSE.
Researchers have drilled three wells in the Arctic of 50-60 meters deep on the shelf of the Laptev Sea and in the sea lagoon adjacent to the Bay of Bore-Haya. It turned out that from the coast of the East Siberian Arctic Sea to the continental slope at a distance of 1000-1500 kilometers there is an ice-containing eternal Merzlot. The upper layer of these sediments consists of non-free soft clay, then sands go, and the third layer consists of ice and sandy soil.
Scientists found out that the thermal conductivity of the frozen soil is approximately 45-60 percent higher than that of non-nominal, due to lower salinity, higher intake and moderate content of non-freeze water. According to the authors of the work, the results indicate that the bottom eternal Merzlot is more vulnerable to thawing than its ground analogue. Degradation of deposits is due to the fact that the ions of the salts are transferred from the upper layers to a deeper ice layer.
destabilization containing permafrost sediments can lead to significant emissions of methane, which is a powerful greenhouse gas that contributes to the heating of the Arctic.