When you work in a special education environment as a learning behavior specialist, no two studentsânor two daysâare the same. Every day is a new day for students with disabilities, and for their instructors.
Drilling began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig. Boreholes were drilled by branching from a central hole. The deepest, SG-3, reached 12,262 metres (40,230 ft) in 1989 and still is the deepest artificial point on Earth. The borehole is 9 inches (23 cm) in diameter. In terms of true depth, it is the deepest borehole in the world.
Not all holes in the Earthâs crust are naturally formed or mysterious in origin. From 1970â1994, geologists in Russia dug the biggest hole in the Earth that anyone had ever seen in the name of science. The result was the Kola Superdeep Borehole, and it eventually reached a depth of 12 kilometers (7.5 mi).