National Park Service Repeat Photography United States Geological Survey Shepard Glacier

1913 - Photo by W.C. Alden, Glacier National Park. 2005 - Photo by B. Reardon, United States Geological Survey.

Shepard Glacier, 1913 - 2005 Glacier National Park What changes are obvious and the ice) are present on the upper viable glacier. What is a glacier? not so obvious in the photo section indicating the glacier A glacier is defined as a body pairs above? The red line on the is flowing and has significant of snow and ice that moves. A Shepard Glacier 2005 repeat photo of Shepard mass. By 2005, however, the commonly accepted guideline Glacier shows the 1913 glacier contemporary photograph for glacier movement is that a boundary. This pair illustrates shows no ice on the bottom shelf, glacier must be at least 25 acres one of the more dramatic cases a small meltwater pond (center), in size. Below this size, the ice of disappearing glaciers. In the and virtually no ice. is generally stagnant and only 1913 photograph, thick ice is moves if it is on a steep slope. evident along the bottom lobe Shepard Glacier, at its current of the glacier and extensive rate of retreat, is below 25 acres crevasses (deep open cracks in and is no longer considered a National Park Service Repeat Photography United States Geological Survey Thunderbird Glacier

1907 - Photo by M. Elrod, Glacier National Park. 2007 - Photo by Fagre/Peterson, United States Geological Survey.

Thunderbird Glacier, 1907 - 2007 Glacier National Park A century of glacial change Thunderbird Glacier is now can be seen from the made up of numerous patches of Thunderbird Glacier Thunderbird pair. Acquiring ice and, when closely examined, the contemporary photograph the 2007 photo reveals a number involved some serious of cliff bands that were covered scrambling on cliffs and by ice in 1907. The corner of a made USGS scientists admire tiny lake is just visible in the 2007 Morton Elrod, the original photo. Thunderbird Glacier will photographer, who carried probably disappear within a few much heavier and bulkier gear years now that it is reduced to a over the same terrain. collection of ice patches. Historic camera gear traveled on horseback. National Park Service Repeat Photography United States Geological Survey Jackson Glacier

1911 - Photo by M. Elrod, University of Montana. 2009 - Photo by L. McKeon, United States Geological Survey.

Jackson Glacier, 1911 - 2009 Glacier National Park Jackson Glacier was once pick out another big change? documented that trees are part of Blackfoot Glacier, one Look at the vegetation growing faster, becoming taller of the largest glaciers in the establishment along Jackson and filling in the spaces in park. By 1939 the expanse of Glacier’s terminus (end point). between trees. Young seedlings Blackfoot Glacier had receded have established and are and separated into two distinct Although melting glaciers are surviving in areas where deep basins, giving rise to the separate the most visible indicators of snowpack and harsh weather Jackson Glacier names of Jackson and Blackfoot climate change in the mountains, conditions had previously glaciers. the entire mountain ecosystem excluded them. is responding. Using both Along with the glacial recession repeat photography and tree- How will this vegetation change evident from this pair, can you ring studies, scientists have impact alpine wildlife? National Park Service Repeat Photography United States Geological Survey Grinnell Glacier

1911- Photo by Stanton, United States Geological Survey. 2008 - Photo by L. Mckeon, United States Geological Survey.

Grinnell Glacier, 1911 - 2008 Glacier National Park The 1911 photo shows Grinnell The Salamander Glacier, now Do all glaciers melt at the same Glacier poised at the top of the separate, lies along the wall below rate? No, melting rates vary waterfalls in the foreground the ridgeline. This glacier is for glaciers based on climate and joined with what is now thinning in the middle so rapidly and other influences such as called Salamander Glacier in that it will likely be in two pieces aspect, elevation, input of Grinnell Glacier the background. George Byrd within a few years. Perched on wind distributed snow, and the Grinnell described this wall the upper left wall is the small, presence of a meltwater lake of ice as being 1,000 feet high rounded Gem Glacier. Although along the glacier’s edge. Even so, in 1887. As of 2008, the wall its area has remained stable, the overall trends show glaciers in of ice was gone and Grinnell glacier is losing volume. the park are receding. Glacier is no longer visible in the contemporary photograph. National Park Service Repeat Photography United States Geological Survey Grinnell Glacier

1926 - Photo by M. Elrod, University of Montana 2008 - Photo by L. McKeon, United States Geological Survey.

Grinnell Glacier, 1926 - 2008 Glacier National Park What makes a good photo glacier. The boulder is now to hike or horseback ride eight to re-photograph? Historic referred to as “Elrod’s Rock” and miles up the Many Glacier Valley images with easily recognizable the glacier’s terminus (the end of to see this glacier. Today, this is a landscape features, like the the glacier) has retreated a half strenuous, but still popular hike Grinnell Glacier photo above, make relocating mile from this point. once the snow has melted from the photo easier. the trail in late summer. Did you also notice the number Grinnell Glacier The large boulder in front of people in the historic photo? of Grinnell Glacier was used Grinnell Glacier was and still is by Morton Elrod and other one of the most photographed scientists as a baseline to glaciers in the park. In the early measure the retreat of the 1900s, park visitors were able National Park Service Repeat Photography United States Geological Survey Boulder Glacier

1932 - Photo by T.J. Hileman, Glacier National Park. 1988 - Photo by J. DeSanto, University of Montana.

Boulder Glacier, 1932 - 1988 Glacier National Park This is one of the earliest of horseback trips through What do these image pairs imply Boulder Glacier photographs repeated from the park and underscores the about climate change? The the park that shows the charisma that glaciers had for climate is warming. Glaciers disappearance of glacial ice. early park visitors. respond to temperature and It helped to start the current precipitation, reflecting long- Repeat Photography Project. The 1988 photo not only shows a term trends. These small alpine completely ice-free view 56 years glaciers are like a visual checking The 1932 photograph shows a later, but shows how vegetation account of the status of the guide, wearing chaps, and three has moved into the area vacated frozen part of the ecosystem. clients next to the ice cave. This by the glacier. Boulder is now was one of the popular multi- too small to be considered a day routes during the heyday viable glacier. National Park Service Repeat Photography United States Geological Survey Sperry Glacier

Circa 1930 - Photo by M. Elrod, University of Montana. 2008 - Photo by L. McKeon, United States Geological Survey.

Sperry Glacier, Circa 1930 - 2008 Glacier National Park Repeating Elrod’s photograph Sperry Glacier is a benchmark continual melt helps regulate from the same photo point was glacier for USGS scientists. They stream temperatures and impossible since the historical use its measurements of annual maintain stream flow during late photograph was shot from the change as a baseline to compare summer and drought periods elevated perspective of the with other glaciers and to predict when other sources are depleted. glacier’s surface. The terminus future changes. Without glacial meltwater, Sperry Glacier of the glacier has retreated summer water temperatures beyond the field of view, but Glaciers store about 69% of the will increase and may cause the these images give a sense of the world’s freshwater and cover local extinction of temperature glacier’s extent and mass early in almost 10% of the world’s land sensitive species, such as aquatic the twentieth century. mass. They act as a “bank” of insects and native trout. water (stored as ice) whose