I recall a quote that if the earth were an onion the deepest humans have dug is like same depth as peeling the outermost skin.
Is this still true?
12.262 km ÷ mean Earth radius 6371 km = ~0.0019
Which is less than a fifth of one percent. On an onion with a radius of say 5 cm, that’s a depth of 0.095 mm. Less than a tenth of a millimeter. That corresponds to, at best, the onion skin, let alone any layers.
And earth has a mean radius of 6,371 km, which means that our deepest bore has penetrated 0.0019247 of the way to the center, or about about one fifth of one percent.
I don’t know exactly how thick the single outer layer of an onion is, but the comparison seems about right to me.
Edit: Damn! Ninjaed!
What is so remarkable about the borehole is how it proved established scientific / geological theories wrong. (And remember this hole is even shallower than an apple skin). Here are two theories it proved wrong :
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“There used to be common understanding among Western scientists that the crust was so dense 5km down that water could not permeate through it." - proven wrong because they found free water down there.
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“Prior to drilling, scientists expected a granite-basalt boundary at around 7 kilometers. However, the project proves that this was not the case.”
As far as the deepest hole humans have dug and can fit into at the bottom the winner is likely the Mponeng gold mine in South Africa.
ETA over 4 km deep.
largest man made excavation in the world is the Brigham Canyon Copper mine near Salt Lake City. Been digging there since 1906. 450,000 tons are removed every day.
Our deepest oil wells in these parts go about three kilometers, but that is not all straight down. Six or seven kilometers is about as deep as any bored well goes. On the plus side, we have done this hundreds or times.
This gives me hope we can get rid of our high-level nuclear waste.
A reference that a lot of people have actually experienced.
Wasn’t this project the source of the urban legend about the scientists who drilled a hole so deep, they penetrated into hell?
Yep.
More like a suburban legend amirite
Yes, a well-known digging created by humans. It definitely qualifies.
Just because Paul Bunyan dug it accidentally doesn’t mean that it should be excluded!
:dubious:
aceplace57 said reference. The man-made hole is six times as deep as something that people have actually experienced.
It is interesting that this XKCD shows the Deepwater Horizon rig drilled to more than 11,000m, but Wikipedia listed it as having drilled only to 10,683m. Either way, they are approaching Kola Borehole depths.
How the hell does oil end up that deep?
Don’t forget the water column. Deepwater Gulf of Mexico wells have at least 1 km of water sitting on top of them, so the actually penetration into the earth is closer to 9-9.3km from the mudline for Macondo. It’s less for other wells, as some of these are drilled in 1.5 to 2 km of water (or more). The 11km figure is a total depth referenced to mean sea level.
The ocean is itself an extreme engineering challenge but it usually doesn’t “count” for many of these lists. But still, to approach Kola depths in that sort of environment is still a pretty big deal, engineering wise.
Jurassic era rock. Used to be the geologists thought all the oil would just cook out and there would be nothing left, but that wasn’t quite right.
Why Jurassic era rock shows up that deep is due to the Mississippi River. In other parts of the world, Jurassic era rock doesn’t occur that deep. But the Mississippi River dumps a lot of sediment into the Gulf. Give that a million years or ten, and it adds up.
nitpick
Bingham, not Brigham. Copper was discovered there by the sons of Mormon pioneer Erastus Bingham while herding sheep. Brigham Young advised against mining because it would divert manpower from farming, which was needed more by the fledgling Mormon community. The name stuck as Bingham canyon, however.
Whatever the word is for layers of the earth folding in and out on each other, and plate tectonics.