 Near the bottom of the first sinkhole, air contained unusually high concentrations of methane, according to tests conducted by the researchers.This hypothesis points to the destabilization of gas hydrates containing huge amounts of methane gas.According to researchers at Norway's Centre for Arctic Gas Hydrate (CAGE), through a process called geothermal heat flux, the Siberian permafrost which extends to the seabed of the Kara Sea, a section of the Arctic Ocean between the Yamal Peninsula and Novaya Zemlya, is thawing.