Watch the glaciers of Kenai Fjords transform before your eyes as nearly a century of change is revealed by repeat photography.

Dr. Bruce Molnia, glaciologist with the U.S. Geological Survey, has been conducting repeat photography research throughout Alaska for the last decade. His work in Kenai Fjords National Park focuses on photographs shot in 1909 by U.S. Grant and D.F. Higgins. Between 1905 and 1909, they completed the first detailed survey of the glaciers of Prince William Sound and the Kenai Fjords coast. Their photographs, archived in Denver, Colorado, provide an opportunity to document a century of change. With support from the Park Service motor vessel Serac, Molnia traveled the Kenai Fjords coast, duplicating the 1909 photos. Using clues such as mountain ridge lines, points of land, and foreground rocks or beaches, he reproduced the composition of the old photos as closely as possible. The new images get a final treatment on a computer to adjust for the focal length of the lens and cropping of the original shot, making the 1909 and modern shots an exact match. The resulting pairs reveal a tremendous amount of information about the changing glaciers of Kenai Fjords. As Dr. Molnia puts it, "If a picture is worth a thousand words, what is the value of two pictures, taken from the exact same location, one hundred years apart."

Much of the rugged beauty of Kenai Fjords National Park is the result of glacier activity. Glaciers still spill down to tidewater today, but it is clear that the extent of many of the glaciers has diminished in recent years. How widespread is the retreat of glaciers in Kenai Fjords National Park? Can monitoring these glaciers tell us anything about global climate change? Many of the glaciers in the Kenai Fjords have retreated dramatically in the last hundred years. For example, McCarty glacier has shrunk back more than fourteen miles, revealing a deep fjord in its wake. However, other nearby glaciers have changed little during this same time period. Is this the result of highly localized climate conditions? Overall, the changes in the glaciers of Kenai Fjords are consistent with a warming regional climate, but local "microclimates" may account for some of the observed differences in rates of retreat. The retreat of tidewater glaciers is also influenced as much or more by interaction between the sea floor and the glacier terminus as it is by the local climate. Ongoing study will help scientists better understand glaciers and their role as indicators of current and future climate change.

View the animated photo pairs.