In the 1980s, it burst into flower and died, as it doesevery 30 to 80 years; but human activity had deprived the pandas of access tolower altitude species that would once have served as a back-up.

The ionizing radiation from the high altitude burst can travel for hundreds of miles before being absorbed. Significant ionization of the upper atmosphere (ionosphere) can occur.

The altitude of an air burst can be varied to obtain maximum blast effects, maximum thermal effects, desired radiation effects, or a balanced combination of these effects.