Not necessarily on the crater.
If this attack was done by a so called Rods From God weapon, then the operative type of ordnance is kinetic which gets its destructive power from pure velocity and mass with velocity being the super main factor. Think of a 20’ long x 12” diameter dart launched from a satellite.
Kinetic Energy (KE) = 1/2 the mass * velocity ^2. So you can see the real bang comes from the velocity factor.
The long rod penetrator rounds delivered from the business end of our M1 Abrams tanks smoke along at a nifty 5,100 feet per second (3,400 MPH) and simply punch a hole in an enemy’s tank hull. But once inside, that penetrator spalls metal everywhere, rattles around causing all kinds of hell to cut loose. Included in that would be detonation of some of the rounds in there.
So these Rods From God...well when cut loose from a satellite are doing orbit velocity. However, dropping through the atmosphere toward earth they slow from air friction...their low cross section helps to minimize the speed loss. In theory the Rod will end up hitting a target doing a real sweet Mach 10...about 7,200 MPH !!!
So...it’s plausible a huge hyper fast kinetic penetrator burrowed hundreds of feet below the surface, breached a huge concrete weaponry dome and cooked-off God knows what all down there.
Implosion.
Thanks. I assume the implosion would erase whatever relatively minor crater occurred at the entry point?