I started by thinking of Nukes, but explosives would be ok, ANFO by the shipload.... I'd buy the DVD, too.
/john
Explosives don't work on ice(bergs) very well..
If you can find a major fracture line it "might" have some effect, but ice simply absorbs most of the explosive force..
The Navy once built a Vessel out of ice.. complete with it's own cooling system to help keep it frozen.. ( The ice was mixed with sawdust to make it even stronger )
It took punishment from artillery and bombs pretty good, but the experiment was discontinued..
I think it was due to the deep draft, and lack of manueverability.. trying to get that much mass moving is an extremely slow process, and changing course or slowing down is just as bad..