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
Novaya Zemlya avalanche that blocked two glacial streams and created a lake in length. Over its history as a nuclear test site, Novaya Zemlya hosted 224 nuclear detonations with a total explosive energy equivalent to 265 megatons of TNT. For comparison, all explosives used in World War II, including the detonations of two US nuclear bombs, amounted to only two megatons. In 1988–1989, "glasnost" helped make the Novaya Zemlya testing activities public knowledge, and in 1990 Greenpeace activists staged a protest at the site. The last nuclear test explosion was in 1990 (also the last for the entire Soviet Union and Russia).