Salmon River Falls: Blue Ice

While most of the falls is white-to-gray, what is it that makes this ice blue? Mineral deposits coming seeping from the upper shelves of sedimentary rock that form this escarpment? Ideas, anyone?

Addendum: Ahhh, Ed has done the research and discovered the science of color seen in ice, explained here. The site explains much more about natural color theory. 

The upshot is that blue color tells us the ice is clearer, so it absorbs more light. It absorbs reds and oranges, and reflects back blue. The more ice reflects light, if it is old and has undergone structural changes, the whiter it appears.

The color has nothing to do with minerals and seeps.