Going back and refreshing memory I believe the crater at OKC was fifty feet deep from 4800 pound anfo bomb.
I have several friends/ aquaintences/ clients who were explosives technicians in the mining industry. They explained to me that when they were cutting the path through Pennsylvania mountains for I-80 they used anfo with a blasting cap on top to prime.
I sure am glad that the intelligent people who possess this knowledge are peace loving people. Most people have no idea of our vulnerability.
Uh, no; 50 feet is really, really deep and would take a much larger explosion, buried deeply, to make a crater of that depth. I going to guess that you haven't much experience with explosives (or dimensions).
My experience is somewhat more lengthy, including taking part in the detonation of nuclear weapons a mile or so into a mountain. You should see the chambers that are created afterward by the fireball.
Not even a fifth of that depth -- and only 18 feet in its longest dimension...
As I said, the OKC crater was covered by eight (8) sheets of plywood.