Repeat Photos of Jackson Glacier

Glacier National Park has always been a dynamic place of change. That makes it a special place to witness and study the power of climate change, both natural and not.

This pair of repeat photographs shows how Jackson Glacier has changed. A version of the left image was published on the cover of William Alden’s 1914 report for the U.S. Geological Survey. The image on the right was taken in 2020. From this pair we can see that Jackson Glacier has dramatically shrunk since the park’s early years.

Jackson Glacier and Mount Jackson in 1914 and 2020

Left image

Jackson Glacier and Mount Jackson by William Alden USGS in 1914

Right image

Jackson Glacier and Mount Jackson by NPS in 2020

Glaciers of Glacier National Park by Alden in 1914

Seeing the glaciers shrink, many scientists have predicted their disappearance.

In 2003, researchers published a scientific paper about two of the park's glaciers in the journal BioScience. They wrote a computer program that would predict glacial advance or retreat for each decade from 1990 to 2100 based on melting rates from historical measurements. However, this early model failed to account for glacier volume and other physical factors that influence glacier melt.

Importantly, the 2003 computer model was not analyzing all the glaciers in the park but just two—Blackfoot and Jackson Glacier. The model used historic melting data to predict that these two glaciers would be gone by 2030—if their current rate of melting continued. It was thought that if Jackson and Blackfoot disappeared by 2030, most of the park’s smaller glaciers would probably disappear by then too.

By 2009, researchers looked again at how fast Blackfoot and Jackson were shrinking and found that they seemed to be melting faster than first predicted. Informally, the 2030 prediction was moved up to 2020. These predictive dates spread widely online and were featured on various exhibits around the park. As 2020 approached, and it became clear the glaciers would not be gone by 2020, the predictions were removed.

As it turned out, Jackson and Blackfoot Glaciers did not disappear by 2020. In fact, they retreated relatively little between 2009 and 2020.

Taking a Repeat Photograph of Jackson Glacier in 2009 and 2020

Left image

Taking a repeat photo of Jackson Glacier from the moraine on September 3, 2009, USGS

Right image

Taking a repeat photo of Jackson Glacier from the moraine on August 29, 2020, NPS

Red: Jackson Glacier in 2005. Blue: Jackson Glacier in 2015.

Though the park's glaciers are all getting smaller, they are not all shrinking at the same rate.

Variations in snow avalanches, ice flow dynamics, and ice thickness cause some glaciers to shrink faster than others. Sometimes a glacier will retreat very quickly where it was thinly and widely spread, only to shrink much more slowly when only the shaded, high elevation ice remains.

Satellites confirm what we see in the photos. The shapes on the left were made from satellite imagery. The glacier’s footprint did shrink during this time, but only a small amount. Jackson Glacier’s total area in 2005 is shown in red and in 2015 is shown in blue. In other words, the red edges highlight the 5% of the glacier’s area that melted away between 2005 and 2015.

Although Blackfoot and Jackson Glaciers have slowed their retreat in recent years, they are continuing to shrink. The most recent measurements show that all the park’s glaciers are getting smaller. Between 1966 and 2015, the area of every named glacier in the park got smaller, some by more than 80%.

Images from 2021 and 2024, taken from Going-to-the-Sun Road, show that the main body of Jackson Glacier had not changed noticeably.

Jackson Glacier Distant in 2021 and 2024

Left image

Jackson Glacier seen at a distance on August 31, 2021

Right image

Jackson Glacier seen at a distance on September 4, 2024

In the left two photos below, it is evident that the glacier retreated hundreds of feet between 1912 and 2009. However, the last image shows little change between 2009 and 2020—good news for people who enjoy seeing ice on the landscape!

Jackson Glacier in 1911, 2009, and 2020.

All signs show that the park’s glaciers are all getting smaller. But not all at the same rate. Depending on how much the climate warms, Glacier National Park could be a place to see melting glaciers for years to come.

Jackson Glacier from lateral moraine in 2009 and 2020

Left image

Jackson Glacier from lateral moraine by USGS on September 3, 2009

Right image

Jackson Glacier from lateral moraine by NPS on August 29, 2020

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Sources

Alden, W. C. (1914). Glaciers of Glacier National Park. United States Geological Survey. https://doi.org/10.3133/70200436 Pp. 3. “Glacier National Park derives its name and much of its interest from the presence of many small glaciers. Very much of the grandeur of its wonderful Alpine scenery, the final sculpturing of the great mountain valleys and of the amphitheaters at their heads, and the production of the basins of its many beautiful lakes are due to the action of the more extended glaciers of the past.”

Martin-Mikle, C. J., & Fagre, D. B. (2019). Glacier recession since the Little Ice Age: Implications for water storage in a Rocky Mountain landscape. Arctic, Antarctic, and Alpine Research, 51(1), 280–289. https://doi.org/10.1080/15230430.2019.1634443 Pp. 284. “Number of glaciers ≥0.1 km2 [equals] 82.”

Fagre, D. B., Mckeon, L., & Fountain, Andrew G. (2017, May 10). Glacier margin time series (1966, 1998, 2005, 2015) of the named glaciers of Glacier National Park, MT, USA. Sciencebase.Gov. https://doi.org/10.5066/F7P26WB1 Miche Wabun, Whitecrow, and Thunderbird Glaciers were all 26 acres in 2015. “The "named glaciers" constitute a subset of the total perennial snow and ice inventory of GNP and do not represent a comprehensive accounting of all glaciers or permanent ice features in the park.”

White, Christopher. The Melting World: A Journey Across America’s Vanishing Glaciers. First. New York: St. Martin’s Press, 2013. 

Pp. 62. “Myrna Hall wrote a FORTRAN computer simulation model, called GLACPRED, that would predict glacial advance or retreat for each decade from 1990 to 2100 based on melting rates from historical data."

**Hall, Myrna H. P., and Daniel B. Fagre. **“Modeled Climate-Induced Glacier Change in Glacier National Park, 1850–2100.” BioScience 53, no. 2 (2003): 131. https://doi.org/10.1641/0006-3568(2003)053[0131:MCIGCI]2.0.CO;2.

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Part of a series of articles titled
Photographing Change in Glacier National Park.

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Repeat Photos of Grinnell Glacier

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