Geologic constraints on clandestine nuclear testing in South Asia

Cavity decoupling in salt is the most plausible means by which a nation cou ld conduct clandestine testing of militarily significant nuclear weapons. T he conditions under which solution-mined salt can be used for this purpose are quite restrictive, The salt must be thick and reasonably pure, Containm ent of explosions sets a shallow limit on depth, and cavity stability sets a deep limit. These constraints are met in considerably <1% of the total la nd area of India and Pakistan, Most of that area is too dry for cavity cons truction by solution mining; disposal of brine in rivers can be detected ea sily. Salt domes, the most favorable structures for constructing large cavi ties, are not present in India and Pakistan. Confidence that they are adher ing to the Comprehensive Test Ban Treaty (CTBT) is enhanced by their geolog ical conditions, which are quite favorable to verification, not evasion. Th us, their participation in the CTBT is constrained overwhelmingly by politi cal, not scientific, issues. Confidence in the verification of the CTBT cou ld be enhanced if India and Pakistan permitted stations of the various moni toring technologies that are now widely deployed elsewhere to be operated o n their territories.