[Southack]

"Can the bunkers be detected in another way?"

Oilfield 3D siesmic will expose tunnels/caves/bunkers.

[Dog Gone]

In theory it could, but 3D seismic is almost always configured to look for stuff far more than a mile deep. I can't imagine these bunkers are that deep. Plus, the turnaround time from acquisition to processing and interpretation is about a year.

It's a good thought, but not anywhere near being a battlefield weapon yet. ;-)