This aerial shot of Johns Hopkins Inlet was taken while winter still grasped a firm hold on Glacier Bay. Here, the ice that you see flowing down the fjord is mostly ‘pan ice’ rather than glacial icebergs. As you can see from the long shadows, the winter sun tracks low across the horizon in the winter, which means that relatively little sunlight reaches the surface of the water. Here, a layer of freshwater rests on top of a much deeper body of denser saltwater. This layer of freshwater, constantly in the shadows, freezes solid. However, as the tides ebb and flow, the level of the sea can shift by as much as twenty feet or more in only six hours. This breaks up the ‘pan’ of ice on the surface, and the ice flows in the only direction it can, out of the inlet. Photographer: Sean Neilson