Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: paul.fr on 04/06/2007 18:43:17

Title: what exactly happens in an underground nuclear explosion?
Post by: paul.fr on 04/06/2007 18:43:17
Do they actually detonate a full nuclear weapon? Get an underground mushroom cloud? Or what?
Title: what exactly happens in an underground nuclear explosion?
Post by: Ashtari on 06/06/2007 15:51:37
Paul.fr

Who is they?  Did someone do that?

Atlantis exploded and then sank....  but they were above ground at the time.

I will let you know when and whether I find some answer.... Very interesting question.

BTW.  Have you heard of Argatha?  The subterranian civilization with an entrance portal in the North Pole.  I believe the Pyramids have tunnels and stairways leading down to this subterranian civilization.


Ashtari
Title: what exactly happens in an underground nuclear explosion?
Post by: daveshorts on 06/06/2007 18:15:22
The mushroom cloud is a fairly late stage of a nuclear blast, when the hot gasses cool to the point where the weight of water and dust over comes their heat and they stop rising. so you get a hot column that stops making the head of the mushroom.

If you set a nuclear bomb off deep enough underground no gas will be able to escape to the surface because of the immense pressure (2-3km down you are at about 1000-1500atm). So the bomb will go off, an immense amount of energy is released, locally the rock will vapourize, this will produce ridiculous pressures and compress the surrounding rock slightly. This produces a shock wave that makes it to the surface and is still very violent, and will lift dust, create spray in water etc. Eventaully the gas will cool down and condense back into rock and the void created will start to collapse.

 Incidently the way you tell it was a bomb and not an earthquake is to look at this shockwave. In an earthquake you have one lump of rock (say on the E side) jumping up against another moving down (say on the W). So when you look at it on your seismometers on the east side it registers an upward movement first, and on the west it registers a downward movement first. A bomb on the otherhand will produce a wave that moves outward first in all directions.
Title: what exactly happens in an underground nuclear explosion?
Post by: Batroost on 08/06/2007 16:26:41
Test depths for underground testing have ranged from just a couple of metres down to about 2500m. There have also been tests under mountains via horizontal tunnels. A classic underground test is deep enough to produce no mushroom cloud (and hence no fallout) but shallow enough to fracture the rock above such that it rises then falls into a 'dished' shape; presumably because this makes its effects easy to measure?
Title: what exactly happens in an underground nuclear explosion?
Post by: DoctorBeaver on 08/06/2007 17:07:39
It gets rid of moles too  [:D]
Title: what exactly happens in an underground nuclear explosion?
Post by: Batroost on 08/06/2007 23:49:56
Oh Yes!  [;D]