Humans have been pushing the boundaries of exploration for centuries, continually testing the depths of the unknown. The deepest underground a human has been is a staggering 10,912 meters (35,797 feet) below the surface of the Earth. This incredible feat was achieved in the year 2018 by a team of Russian scientists at the Kola Superdeep Borehole, located near the Norwegian-Russian Border.
The Kola Superdeep Borehole is an impressive feat of engineering, having been dug by a team of Russian scientists with the purpose of reaching the Earth's mantle. The project was initiated in 1970 and lasted until 1992. It took the team of scientists over 20 years to complete the project with a total of 12.3 kilometers (7.6 miles) of drilling. The deepest of these drillings ultimately reached a depth of 10,912 meters (35,797 feet).
The scientific team encountered various challenges during the drilling, from the intense heat caused by the friction of the drill bit against the rock to the incredible pressures at such depths. The pressure at this depth was estimated to be between 180 and 200 atmospheres, or 2,700-3,000 pounds per square inch. The intense pressure caused the drill bit to need to be replaced several times during the process as it was worn down.
The team of scientists also encountered a variety of geological phenomena during their drilling. At depths of 4,000-7,000 meters (13,123-22,965 feet), they observed a layer of basalt, a type of igneous rock, which is thought to form the Earth's mantle. At depths of 8,000-9,000 meters (26,246-29,527 feet) they encountered a layer of sedimentary rock, and at depths of 10,000-10,900 meters (32,808-35,761 feet) they encountered a layer of metamorphic rock.
The Kola Superdeep Borehole is a remarkable achievement in human exploration, and is an important part of our understanding of the Earth's structure. Not only did the team of Russian scientists reach an incredible depth, but they also encountered a variety of geological phenomena which have given us a greater insight into the Earth's structure. The project is a testament to both the ingenuity of the human mind and the power of exploration.