I am sorry I am not following the connection between Pokhran-II nuclear tests and Australia. Would you mind sharing some more information or a link maybe?
Ostensibly for a routine few hundred thousand line kilometres of geophysical survey in northern India for mineral exploration.
Contracted to a cutout company.
It just happened to be the first such survey in India and to coincidentally be at the exact place and time the area turned into an underground nuclear test site.
I would hazard that there is a good bit of transmission of shock waves from below to the surface, but it's ofc attenuated by the large mismatch in density at the ground air-interface...
The plane was buffeted, the crew were unhurt, on the day.
Their diginity took a mild beating after landing and spending a month under quasi "friendly" house arrest by Indian troops who watched them gather more data and process it, compounded by questioning from US border agents in following years in transit, and offset by the joy of watch high caste Indian Geophysicists that insisted on being in the planes vomit on every end of line turn.
( It's a gut wrenching maneuver )
Telling them the planes weren't landing and they'd have to clean up their own mess "sparked joy", I believe.
True story, and these days you'd probably have to go to paper copies to find quotes from senior US defence | politicians expressing surprise at tests that seemingly came out of nowhere.
I dare say somebody might write it up well after retirement for release after death.
Things got ... interesting.