Crustal drilling begins on the Kola Peninsula; the borehole, called Kola SG-3 Zapolyarny, will reach a depth of 12,262 meters in 1989, without reaching the Earth’s fluid mantle. However, it will encounter a deep layer of fractured, water-saturated rock at a depth of around 5 kilometers. In terms of drilling length, it has been surpassed by the Al Shaheen Oil Field in Qatar by a few meters, but the Kola Peninsula remains the deepest.
