Spring breakup No flash player has been set up. Please select a player to play Flash videos. Video not playing? Update your browser or download the video clip While standing at the end of the airport runway, Sam Demientieff talks about how the river is unpredictable in the spring during breakup and creates ice jams. Process Observed: Ice CollapseChanges in River ChannelIce Jam Date Process Observed: Wednesday, March 23, 2011 Galleries: End of Airport Runway Gallery