A research team from the Petroleum Center at Skoltech and other institutions continues a series of studies exploring bottom sediments and subsea permafrost in the Arctic. The new paper, published in the Marine and Petroleum Geology journal, compiles data from expeditions and introduces new results of bottom sediment studies in the Arctic seas (the Kara Sea, Laptev Sea, and East Siberian Sea) focusing on their temperature characteristics and reasons behind their formation. Researchers contribute to the Arctic exploration and provide insights into the global warming challenges.
The Earth’s climate keeps changing, which is escalated not only by human activity and carbon dioxide emission, but also by methane entering the atmosphere in large proportions. Cattle breeding is considered its key source, but it also increasingly comes from wetland ecosystems and results from the natural degasation of the Earth. The greenhouse effect of methane is much higher than that of carbon dioxide. According to the Intergovernmental Panel on Climate Change established for evaluating the influence of human activity on global warming, within 100 years the share of methane in global climate change is expected to be 28 times higher compared with carbon dioxide.
The Arctic region is extensively developed by many countries. As authors argue, more than 80% of its subsea permafrost belong to the Russian Arctic seas — the Laptev Sea, East Siberian Sea, and Chukchi Sea. Subsea permafrost is considered to contain much methane. As a result, when it degrades, methane is released from permafrost to the water column above it and then to the atmosphere. Among its sources are gas hydrates (compounds of water and low-molecular gases forming at a certain temperature and pressure), gas accumulations in the permafrost, and deep-seated gas flows entering through areas of increased permeability and faults. When temperature is rising, gas hydrates start decomposing. It is estimated that decomposition of gas hydrates will produce much more methane than today’s level in the atmosphere.
“We would like to highlight research into bottom sediment temperatures, which is an indirect sign of subsea permafrost. It allows estimating whether the area under study has permafrost and revealing effects from other factors: river flows, undercurrents, decomposition of gas hydrates, and deep heat flows,” says Leading Research Scientist Evgeny Chuvilin from the Petroleum Center.