Arctic methane emissions permafrost thawing. 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. According to a CAGE researcher, Aleksei Portnov, Methane hydrate is leaking in an area of at least
Severnaya Zemlya appeared to the north of the archipelago. Although located not far off the northern coast of Russia, nested among Arctic ice-locked waters, the archipelago that is now known as Severnaya Zemlya was not formally recorded until the 20th century. Earlier explorers deemed that there was a land mass in the general area of the archipelago, such as in the report by Matvei Gedenschtrom and Yakov Sannikov made in 1810 at the time of their exploration of the New Siberian Islands. Later in the 19th century Adolf Erik Nordenskiöld during the Vega Expedition sailed very close to this land in 1878