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Drilling to the Center of the Earth
indylaw writes "Japanese scientists are attempting to explore the centre of the Earth." From the article: "Using a giant drill ship launched next month, the researchers aim to be the first to punch a hole through the rocky crust that covers our planet and to reach the mantle below. The team wants to retrieve samples from the mantle, six miles down, to learn more about what triggers undersea earthquakes, such as the one off Sumatra that caused the Boxing Day tsunami."
12-25km through the oceanic crust is *not* the centre of the earth.
Slashdot: Where nerds gather to pool their ignorance
This article is very interesting. This article is very interesting.
The mantle IS NOWHERE NEAR the center of the earth. More /. titling sensationalism.
Still, drilling even 6 miles down is quite a feat
I even emailed the on duty editor before the article was posted to warn him. I even emailed the on duty editor before the article was posted to warn him.
1. Build giant probe to drill to the center of the earth
2. Arm the probe with nuclear weapons
3. Hold the world hostage for... ONE MILLION DOLLARS
4. Profit!
...what if there were no rhetorical questions?
There have been a number of other projects to drill deep into the Earth's crust, though none has succeeded in reaching the mantle, as this Japanese team is trying to do. Some of the more well-known ones:
Another poster already provided the wikipedia page for Project Mohole. That was a US team back in 1961 that managed to drill to 183 m below the sea floor, in 3500 m of water off the Mexican coast. From a ship, floating on the ocean surface -- I just find that incredible.
As far as land-based projects go, there have been 2 big ones that I know of. The Kola Superdeep Borehole was a Russian project, started in 1970, that drilled at a site on the Kola Peninsula near Finland. Their deepest hole reached 12.262 km in depth, which is the current record. This page has a section (scroll down a few screens) with some very interesting findings from the project. Apparently, geologic theory doesn't quite correspond with what we find when we actually go down there to see for ourselves.
There's also the KTB (long German acronym) Borehole, started in 1978 in Bavaria. They reached a depth of 9.101 km. Information on this one is hard to find, at least in English, though there is a great Oilfield Review article (big pdf) available.
This Japanese project is going to drill through the sea floor in the Pacific, in a spot where the crust is thin, which will hopefully allow them to reach the mantle in only 7 km, under 2.5 km of water. For comparison: the previous record seafloor drill was only 2.1 km. So they've definitely got their work cut out for them.
I hope they don't wake up some million year old creature that then terrorises Tokyo and makes all the girls scream!
This is serious. Somebody should stop them. Otherwise, they will pop the planet like a balloon, causing the insides to gush out into space, and the Earth's crust to fragment and fly off in all directions. Those parts of the crust left intact will shrink to a small fraction of their former size (just like a ballon's skin), once the air is let out of the Earth. On the plus side, traveling from point A to point B will take much less time, once the crust has shrunk, but point A and point B will themselves be much smaller. Houses in the suburbs will start to look like houses in the city, i.e., scrunched up against each other with small to non-existent back yards. No back yards! Where will yuppies hold their barbeques? My god, my god! We have to stop them before they pop the planet!
Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
I will further butcher the analogy by pointing out that the core is likely composed of two regions: a liquid outer core and a solid inner core. So the earth is really more like those crazy chocloate covered cherry liquor thingies. (if covered in a sweet candy shell. mmmm)
Can you be Even More Awesome?!
Specific heat of Nickel/Iron 440j/(kg-K)
Temp ~6000K
Density of Iron 7800kg/m^3, Nickel 8900km/m^3
Diameter of outer core ~5000km
Mass of core = 5*10^24 kg, less than the mass of earth = 5.97*10^24
Heat content of core = 12*10^33 J, which combined with this data of 12 trillion kwh electricity usage/year = 43*10^18 J/year gives us over a billion years to drain it 1%, well past the life of our planet.
The road to hell is paved with good intentions.