underground explosions

[dragon]

I was wondering whats happens when large scale explosion say a few gigatons were to explode a few at the boundary layer between the crust and the mantle. Especially if there are shafts still leading to the surface.

[Lord Revan]

Well a portion of blast would go up the shaft(s) (if they existed) as air would provide less resistance then solid matter of crust or molten matter of mantle, beond that I don't know.

[dragon]

Ok a few web searches and all I could figure out there would be some major earthquakes, not sure how wide spread. Plus would a volcano form as all the molten rock was forced up the shafts?

[Crossroads Inc.]

The closest you can get to this is experiments in the 50's that the US Government did when they exploded some low yield A-Bombs underground as part of an experment to see if A-Bombs could used in large scale minning.

[Uraniun235]

United States underground nuclear weapons testing continued into the very early 90's, since above-ground testing had been banned some decades prior.

[SyntaxVorlon]

That level of energy at that level in the crust, maybe set off a chain of earthquakes, I think 5-6 is gigaton level energies as far as earthquakes go, so maybe 2-3 once it hits us.