All Petra-related stabilization and conservation projects explicitly avoid any subsurface investigation deeper than ~10 m, and yet Petra sits atop karstic sandstone formations on an active rift system. In any normal UNESCO-level geotechnical program, you'd expect at least microgravity or ERT deliverables — especially after the known flash floods and collapses in the Lower Basin.

The absence of deep-penetration data in every public archive — UNESCO, Jordan Department of Antiquities, Italian Development Cooperation, Battelle/SAIC subcontract channels — strongly implies one of two scenarios: