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Monday, May 24, 2010 03:05PM

Daily TWiP – The Kola Superdeep Borehole is begun today in 1970

Week in Preview

Welcome to Daily TWiP, your daily dose of all the holidays, historical observances, etc., we couldn’t cram into The Week in Preview.

Most of us, at one point in our childhoods, have attempted to dig a hole to the center of the Earth with a shovel and pail. Today (May 24) in 1970, the former Soviet Union decided to see how deep modern technology could take them when they began work on the Kola Superdeep Borehole.

The goal of the project was to drill as deep as possible into the Earth’s crust and, essentially, see what was there. In the Kola Peninsula, where the drilling took place, the crust was estimated to be about 22 miles thick, so a target depth of 49,000 feet (or 9.28 miles) was chosen.

A Uralmash-4E drilling rig was employed at first, followed by a Uralmash-15000 in later years. A single central hole was made and then various other holes were drilled off of the central hole.

The process was somewhat time-consuming. It took nine years to surpass the depth of the world’s deepest hole, which at the time was the 31,440-foot deep Bertha Rogers hole in Washita County, Okla.

The project took a year’s hiatus in 1983 to celebrate having reached a depth of 39,000 feet. Soon after restarting, however, the drill broke, and the team had to start another hole off of the hole in which they had previously been drilling, as that hole was now blocked by a 16,000-foot piece of busted drill.

By 1989, the hole was 40,230 feet (7.6 miles) deep. It was around this time that rumors began to circulate that the hole had drilled into Hell itself. With the aid of a heat-tolerant microphone, it was claimed, the workers had been able to hear the screams of the damned. This misinformation is still floating around the Internet today, and the claims are just as unfounded as they were 20 years ago.

It was estimated that at the current pace of work, the target depth of 49,000 feet would be achieved by 1993, but unfortunately, as the hole became deeper, the temperatures encountered were almost twice as hot as had been anticipated. The temperature was now estimated to be a whopping 570 degrees Fahrenheit at the target depth. The drill would no longer work in such intense heat. With the target depth deemed unrealistic, drilling was concluded in 1992.

Although the project wasn’t able to achieve its initial goal, it provided invaluable geophysical research opportunities and countless rock and mineral samples – as well as earning Russia the distinction of the world’s deepest drilled hole. The Kola Superdeep Borehole site has since been incorporated into Russia’s Deep Geolaboratory.

Daily TWiP appears Monday through Friday courtesy of The Week in Preview. Check out The Week in Preview online in our Columnists section at or read it in print on Mondays in our Nashua and Region section.

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- Teresa Santoski