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The world's deepest hole lies hidden beneath this rusty metal cap
Beneath this rusty old metal cap lies some of our world's deepest mysteries. Though it measures just 9 inches in diameter, the hole beneath the cap extends 40,230 feet under the Earth, or 7.5 miles. That's roughly a third of the way through the Baltic continental crust. It's the deepest borehole in the world.
The Kola Superdeep Borehole was drilled between 1970 and 1994 in a Cold War-era attempt by the Soviets to beat the United States in a race to drill to the center of the Earth — or to get as close to the center as possible. Though the space race stole all the headlines, this less-publicized subterranean quest was equally as competitive. The mysteries that it unearthed are still being analyzed today.
Before the hole was drilled, geologists could only hypothesize about the composition of the Earth's crust. Needless to say, the amount of geological data produced by the project was unprecedented. Mostly, it revealed just how little we really know about our planet.
For instance, one of the most surprising findings was the absence of the transition from granite to basalt at a depth between 3 and 6 kilometers below the surface. Previously, scientists had used seismic waves to glean information about the composition of the crust. They had discovered that a discontinuity existed at this depth, which they assumed was due to a transition in rock type. But the borehole drillers found no such transition; instead they found only more granite. It turns out that the discontinuity revealed by the seismic waves was actually due to a metamorphic change in the rock, rather than a change in rock type. It was a humbling realization for theorists, to say the least.
Read more: http://www.mnn.com/lifestyle/eco-tourism/stories/the-worlds-deepest-hole-lies-hidden-beneath-this-rusty-metal-cap
36 replies
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I could move my outhouse over it...Never have to dig another pit....
