The Deepest Hole in the Earth - Kola Superbole Hole
Born to Explore
Man is a great explorer by our very nature, always curious and seeking beyond what is already known.
This applies to everything from scientific research, to interstellar travel and ocean exploration.
There is, however, a place right beneath our feet that remains virtually unknown.
What exactly lies deep underground, and why is it relatively unexplored?
The Deepest Mines
Mining has been taking place for thousands of years as we look to exploit the Earth’s resources for our gain. Coal, precious metals, oil, gas and other resources are taken and turned to good use for humanity's benefit and comfort of life.
AngloGold Ashanti's Mponeng gold mine, just to the South-West of Johannesburg in South Africa, is the world’s deepest mine and reaches a depth of just over four kilometres. Indeed, eight out of the ten deepest mines in the world are in South Africa, with the other two located in Canada.
When you consider that the radius of the Earth is 6,371km, these mines are barely scratching the surface at approximately 0.062% of the distance to the centre of the planet.
There is, however, a place in Russia which is three times that distance. In terms of percentage, it is still a minuscule depth at 0.189% of the Earth’s radius, but at twelve kilometres it's three times deeper than the deepest mine and is as far as man has ever journeyed towards the centre of the Earth.
The Race for the Mantle
Known as the Kola Superdeep Borehole, it is located on the Kola Peninsula in North-West Russia. The peninsula is inside the Arctic Circle and borders both Finland and Norway, with the nearest major Russian city being Murmansk.
The concept was initiated as part of the Cold War battle between the Soviet Union and the USA as they locked horns and tried to out-do each other in all manner of political and scientific ways, most notably the space race, which ended in 1969 with the USA landing a man on the moon.
Both nations set out with the intention of drilling below the Earth’s crust into the area between the crust and the mantle, known as the Mohorovic Discontinuity.
The crust is estimated to be somewhere between 35 and 50 km in thickness. Plans were developed in the late 1950s and early 1960s, with the resulting American 'Project Mohole' off the Pacific Coast of Mexico, and the Russians with their Kola Superdeep Borehole.
This time the Russians came out clear victors, with the American project running out of funding in 1966, just five years after drilling began.
What Was Learned From This Project?
The actual drilling began on the nine inch wide Kola borehole on May 24th, 1970 and ceased 24 years later due to reaching unexpectedly high temperatures of 180°C (356°F) that made the rocks behave more like plastic than rock.
This combination of rock behaviour and high temperature made further drilling unfeasible and work ceased. The site is now abandoned and run-down.