Kola Superdeep Boreholeとは 意味・読み方・使い方

The Kola Superdeep Borehole (Russian: Кольская сверхглубокая скважина) is the result of a scientific drilling project of the Soviet Union in Kola Peninsula. The project attempted to drill as deep as possible into the Earth's crust. Drilling began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig. A number of boreholes were drilled by branching from a central hole. The deepest, SG-3, reached 12,262 metres (40,230 ft) in 1989, and is the deepest hole ever drilled, and the deepest artificial point on earth. For two decades it was also the world's longest borehole, in terms of measured depth along the well bore, until surpassed in 2008 by 12,289 m (40,318 ft) long Al Shaheen oil well in Qatar, and in 2011 by 12,345 metres (40,502 ft) long Sakhalin-I Odoptu OP-11 Well (offshore the Russian island Sakhalin).