Uploaded April 2026 | Updated September 2026, 3 weeks ago
The Kola Superdeep Borehole, drilled by the Soviet Union from 1970 to 1989 on Russia's Kola Peninsula near the Norwegian border, remains the deepest artificial hole ever created on Earth. Reaching a vertical depth of 12,262 meters (40,230 feet, or about 7.6 miles), this narrow 23-centimeter (9-inch) borehole far surpasses the depth of the Mariana Trench and exceeds the height of Mount Everest when measured from base to summit.
This ambitious scientific project aimed to penetrate deep into the Earth's continental crust, studying its composition, structure, and the transition toward the mantle at the Mohorovičić discontinuity. The effort revealed unexpected findings: temperatures rose much faster than predicted, hitting around 180°C (356°F) at the bottom—nearly double the anticipated heat—causing rocks to behave plastically and equipment to fail. Water-saturated fractures deep underground also produced surprising hydrogen-rich fluids and ancient microfossils preserved in 2.7-billion-year-old rock.Drilling halted in the early 1990s due to extreme conditions, funding shortages after the Soviet Union's collapse, and technical limits, leaving the hole only about one-third of the way through the crust.
The site was eventually sealed and abandoned.In this video, we explore the engineering challenges of ultradeep drilling, the groundbreaking scientific discoveries from core samples, and what this record-breaking feat tells us about Earth's interior—while addressing why humans have never drilled farther and what modern efforts in places like China are achieving today. Join us to uncover one of the most extreme feats of human exploration beneath our planet's surface.
The Kola Superdeep Borehole, drilled by the Soviet Union from 1970 to 1989 on Russia's Kola Peninsula near the Norwegian border, remains the deepest artificial hole ever created on Earth. Reaching a vertical depth of 12,262 meters (40,230 feet, or about 7.6 miles), this narrow 23-centimeter (9-inch) borehole far surpasses the depth of the Mariana Trench and exceeds the height of Mount Everest when measured from base to summit.
This ambitious scientific project aimed to penetrate deep into the Earth's continental crust, studying its composition, structure, and the transition toward the mantle at the Mohorovičić discontinuity. The effort revealed unexpected findings: temperatures rose much faster than predicted, hitting around 180°C (356°F) at the bottom—nearly double the anticipated heat—causing rocks to behave plastically and equipment to fail. Water-saturated fractures deep underground also produced surprising hydrogen-rich fluids and ancient microfossils preserved in 2.7-billion-year-old rock.Drilling halted in the early 1990s due to extreme conditions, funding shortages after the Soviet Union's collapse, and technical limits, leaving the hole only about one-third of the way through the crust.
The site was eventually sealed and abandoned.In this video, we explore the engineering challenges of ultradeep drilling, the groundbreaking scientific discoveries from core samples, and what this record-breaking feat tells us about Earth's interior—while addressing why humans have never drilled farther and what modern efforts in places like China are achieving today. Join us to uncover one of the most extreme feats of human exploration beneath our planet's surface.
