The Kola Superdeep Borehole is 12,262 m deep. Until recently surpassed by a couple of oil wells, it was the deepest hole ever drilled. It’s located in the Kola Peninsula in northwestern Russia. The Soviets started drilling in 1970, and unlike the slightly-deeper oil wells, their purpose was scientific. What goes on deep within our planet’s crust had never been directly observed, and now people were bringing up samples from the depths. One of the things they found was really what they didn’t find. The Conrad discontinuity is a boundary where seismic waves suddenly change velocity. This was theorized to represent a boundary between granite and basalt, but the Russians found no such boundary. They did find a layer of rock shattered by water that may have been squeezed out of the rock below, but which couldn’t penetrate to the surface.
What’s under the structure on the picture isn’t one big hole, but a central hole with different off-shoots. The 12 km-long hole isn’t more than nine inches wide. The original goal was reaching 15,000 meters, but the drilling had to stop when unexpectedly high temperatures were reached, causing equipment to malfunction. (This may be the source of that urban legend about Russians drilling a hole straight into hell.) Due to a lack of funding, there is no activity at the Superdeep Borehole today, but the samples brought up are still available for analysis.
dailymeh posted this on July 28, 2011
