"Triggering natural risks", you say. Well, it is possible. But there is actually an interesting correlation: https://drive.google.com/file/d/0B5thEFwXjxvTWkt0djJ3akpQNHM/view?usp=sharing Top plot - summary energy of all (disclosed) underground nuclear blasts (converted to magnitude) Bottom plot - earthquakes with magnitude >= 8.3.
Source: http://ufn.ru/ru/articles/2010/3/f/ (unfortunately, in russian only, don't know if anybody published similar research in english).
So, maybe it is possible to use nuclear blasts to prevent natural risks, not trigger them.
Uh, sorry, I thought the image was public, it should be now.