Glaciologists will find this video obvious. Everyone else... well, maybe I slept through a bit of sixth-grade geography, but I didn't know this, and I reckon I should have done. Pull down the description for more! I'm here because of Chris Hadfield's Generator Arctic - go check out everyone else who was on the trip, and have a look at tickets for their show at Massey Hall, Toronto, on November 12th! http://generatorevent.com