Tsar Bomba C), north of the Arctic Circle over the Novaya Zemlya archipelago in the Arctic Ocean. The bomb was dropped from an altitude of ; it was designed to detonate at a height of over the land surface ( above sea level) by barometric sensors. The original, November 1961, United States Atomic Energy Commission estimate of the yield was 55–60 megatons, but since 1992, all Russian sources have stated its yield as 58.6 megatons. First secretary Khrushchev warned in a filmed speech to the Supreme Soviet of the existence of a 100-megaton bomb (technically the design was capable of this yield.)
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).