PDA

View Full Version : negative consequences of digging deep into the Earth?



SRH
2014-Jan-01, 03:22 PM
Is it possible that digging to the lower mantle of the Earth could cause an earthquake or volcanic eruption?

dgavin
2014-Jan-01, 04:51 PM
I've thought about that. Digging to the lower mantel? Not possible with current technology. Additionally, once you get past 100km or so, the rock starts becoming a softer plastic like substance (magma) which would melt drill heads. However that being said, fracking in the crustal region has been know to cause earth quakes there, and there have been a few mud volcanoes and hydrothermal geysers caused by drilling activities.

Squink
2014-Jan-01, 09:29 PM
Digging to the lower mantel? Not possible with current technology.Tom Swift bored a hole to the iron core with his Atomic Earth Blaster (1954) (http://guanaco17.blogspot.com/2011/02/book-covers.html), with spectacular results. But even if such a thing were possible in real life, the dense molten material would rise only until it was at equilibrium pressure with the rest of the core, well short of the surface; Iron being about 3x as dense as crustal rock.
Seems to me you'd have to excavate a very large hole to initiate formation of a mantle plume capable of prolonged vulcanism.
You might run into problems if you dug into the Yellowstone Caldera, or under Newberry, where the magma is A)gassy, and B) of a density not so different from surface rock.

Local Fluff
2014-Jan-11, 07:51 AM
One could concentrate cobalt 60, which radioactively generates heat, inside a tungsten capsule with higher melting point and let it melt its way into Earth. It would reach the upper mantle over 100 km deep after a few decade. There I suppose that the density is too high for it to proceed. By tracking it seismically, one could learn something about the composition of the matter it passes through.
http://tinyurl.com/mns97k7

Earth radius is 6370 km, so even such an extreme method really just scratches the surface. The inner of the planets (and of course stars) are the most unreachable areas in space. And those areas contain most of all ordinary matter, så one could say that even ordinary matter is mostly "dark" as in unattainable. We have to make do with thin surfaces and the dust (asteroids) between them.

Fracking causing tiny Earth quakes is a very shallow phenomena. I'd guess it has to do with water pressure on the groundwater.

NEOWatcher
2014-Jan-13, 04:13 PM
In the world of quakes and tremors, I think people unfairly lump any small quake with those created due to techtonic activity.

For instance:

Fracking causing tiny Earth quakes is a very shallow phenomena. I'd guess it has to do with water pressure on the groundwater.
I'm not sure that they have determined a definite cause yet, but I think it's from the fracturing of the oil bearing rock itself.
I would think it would be similar to a frost quake (http://en.wikipedia.org/wiki/Cryoseism), but deeper down.


So; even if digging deep into the Earth could cause a quake, I really don't think it would be a problem.