Ice bridging during freeze-up on the Susitna River, Alaska, November 6, 2013
PhD student Julia Blackburn took this great photo on a recent trip to Alaska – she was there to observe freeze-up on the Susitna River as part of her research project. Border ice development at this naturally occurring constriction has resulted in surface ice bridging. However, at the time Julia took the photo, the current was so strong that any incoming ice was being swept under the bridge and spat out the other side, impeding further development of the ice cover at this location.
(Photo by Julia Blackburn, Nikon Coolpix AW100, f/3.9, ISO-640, FL 28 mm, 1/200 sec. exposure)