Where is the deepest borehole

The crust is just a tiny portion of the planet—averaging three to 25 miles thick. Scientists took their first crack at the mantle in with Project Mohole. American engineers drilled through the Pacific Ocean floor off Guadalupe, Mexico.

But Congress discontinued funding in before the drillers ever reached the mantle. The quest to drill deeper created a global scientific contest akin to the Space Race. In , Soviet geologists took on the challenge , setting their drills over the Kola Peninsula, which juts eastward out of the Scandinavian landmass.

The Kola Superdeep Borehole was just 9 inches in diameter, but at 40, feet 12, meters reigns as the deepest hole. The German borehole has been spared the fate of the others. The huge drill rig is still there — and a tourist attraction today — but today the crane just lowers instruments for measurement. The site has become in effect an observatory of the planet — or even an art gallery. Others thought they could hear the planet breathe. Then where we were drilling was just much hotter than where the Russians were.

It was pretty clear that it was going to be much more difficult for us to go any deeper. No one had got to it before. It was really exciting. There are always surprises. As with the original Project Mohole, the scientists are planning to drill through the seabed where the crust is only about 6km 3. What we are trying to do is find out more about the Crust-Mantle boundary. One of those is off Costa Rica, one off Baha, and one off Hawaii. Each of the sites involves a compromise between the depth of the ocean, distance from the drilling site and the need for a base on the shore that can support a billion-dollar, hours-a-day operation at sea.

They can cost hundreds of millions of euros — and only a small percentage will actually be for the earth sciences, the rest will be for technological development, and of course, operations. Join more than one million Future fans by liking us on Facebook , or follow us on Twitter or Instagram. If you liked this story, sign up for the weekly bbc. Drilling was later restarted from 7, m 23, ft.

The drill bit could no longer work at such temperatures, and drilling was stopped in All the drilling and research equipment was scrapped and while data produced by the Kola drilling project continues to be analyzed, the site itself has been abandoned since ; the hole was welded shut by the metal cap we still see today, as if to seal off any devils or mysteries that might lurk beneath.

Join the ZME newsletter for amazing science news, features, and exclusive scoops. More than 40, subscribers can't be wrong. Andrei's background is in geophysics, and he's been fascinated by it ever since he was a child. Feeling that there is a gap between scientists and the general audience, he started ZME Science -- and the results are what you see today. The rocks themselves also become more malleable.

The Russian scientists in Kola described the rocks at those depths as behaving more like plastic than rock. Since the drilling was stopped in , and the project site was abandoned around a decade later, the Kola Superdeep Borehole has maintained the record for the deepest artificial point on Earth. Humans have since dug longer boreholes, including the 12,meter borehole drilled in the Al Shaheen Oil Field in Qatar and the 12,meter offshore oil well near the Russian island of Sakhalin.

But the hole in Kola remains the deepest. There are a few reasons we humans dig deep into the Earth—extracting resources like fossil fuels and metals, for starters. A year-old copper mine in the mountains near Salt Lake City, Utah hosts a pit that extends three quarters of a mile deep and spans 2. At meters, the Kimberley Diamond Mine in South Africa is one of the largest holes in the world dug by human hands. We also dig, of course, for science.