Help modeling a glacier.

I want to do a little test in cycles and model an ice glacier and was wondering where or how to start. Would i start with an icosphere and add a disp map, or just start with a cube or maybe use the ANT landscape generator? Any help is appreciated. Here’s a ref pic of what i’m going for --> http://icestories.exploratorium.edu/dispatches/wp-content/uploads/2008/12/ice_9.jpg