Hey Cpt. Robertson, I'm not quite sure why a 1m "ANYBODY PRESENT" trigger over the mine isn't good enough... Is there some specific reason why you want to use a script..?
The script would give you flexibility for the name of the mine to detonate by passing it into the script, but you're still left with the problem of actually telling the game it needs to run the script to set this mine off. The basic mechanism to do this is a trigger.
I guess what I'm saying is, no matter which way you do it with a simple trigger with the appropriate line in the OnAct: field, or via a script it will involve a trigger at some point as far as I can see. I could be wrong, but I don't think so... Especially if you aren't looking for a specific unit name or <player>... :-\
Sorry if this doesn't help much...