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 numbering 298, was removed to the mainland in 1957 before nuclear testing began. In 1943, during World War II, Novaya Zemlya briefly served as a secret seaplane base for Nazi Germany's "Kriegsmarine", to provide German surveillance of Allied shipping en route to Siberia. The seaplane base was established by U-255 and U-711, which were operating along the Northern coast of Soviet Russia as part of "13th U-boat Flotilla". Seaplane sorties were flown in August and September 1943. In the months following Hitler’s June 1941 invasion of the Soviet Union, the United States and Great Britain organized convoys of merchant ships