Kola Superdeep Borehole

Rare card · No. 18420

The Kola Superdeep Borehole SG-3 (Russian: Кольская сверхглубокая скважина СГ-3, romanized: Kol'skaya sverkhglubokaya skvazhina SG-3) has been the deepest human-made hole on Earth since 1979, attaining a maximum true vertical depth of 12,262 metres (40,230 ft) in 1989. It is the result of a scientific drilling effort to penetrate as deeply as possible into the Earth's crust conducted by the Soviet Union in the Pechengsky District of the Kola Peninsula, near the Russian border with Norway. SG (СГ) is a Russian designation for a set of superdeep (Russian: сверхглубокая) boreholes conceived as part of a Soviet scientific research programme in the 1960s, 1970s, and 1980s. Aralsor SG-1 (in the Pre-Caspian Basin of west Kazakhstan) and Biyikzhal SG-2 (in Krasnodar Krai), both less than 6,810 metres (22,340 ft) deep, preceded Kola SG-3, which was originally intended to reach 7,000 metres (23,000 ft) deep. Drilling at Kola SG-3 began in 1970 using the Uralmash-4E, and later the Uralmash-15000...

Read on Wikipedia · Image Andre Belozeroff, CC BY-SA 3.0