Ice Cliff, Columbia Glacier, Alaska
W. Tad Pfeffer (INSTAAR/CEAE, UCB)

Photography
Columbia Glacier terminates in the ocean at Prince William Sound, Alaska, and is presently the largest single Alaskan contributor to global sea level. The glacier is rapidly retreating up its fiord by a process driven not simply by warming-induced melt but by interactions between melt and internal dynamics. The recent initiation of similar dynamic retreats in Greenland may substantially increase global glacier contributions to sea level, and the future rate of sea level rise may be much greater than presently published projections. The photograph suggests the complexity, force, and delicacy of the physical environment at the ice cliff. A sense of scale is hard to discover; the ice cliff is 2.5 km wide and stands approximately 70-100 m above the water line, but no visual cues exist, either in the photograph or actually at the scene, to help the viewer. Sizes and perspectives are invariably deceptive—people, boats, aircraft, are visually lost in the landscape. The viewer's inability to grasp the scale adds an additional sense of uncertainty to what may happen here in the future.

Traveling