Glaciers and Climate Project

Sperry Glacier

Map showing the location of the South Cascade Glacier

Elevation Range: Approximately 2300—2600 meters
Location: Latitude: 48°37'19.53"N, Longitude: 113°45'24.50"W
Area: 0.8 km2

Sperry Glacier, with an area of approximately 215 acres, is one of 25 remaining glaciers in Glacier National Park, MT
Sperry Glacier, with an area of approximately 215 acres, is one of 25 remaining glaciers in Glacier National Park, MT

Sperry Glacier is a winter-accumulation type glacier that occupies a broad, shallow cirque situated just beneath and west of the Continental Divide in the Lewis Mountain Range of Glacier National Park, Montana. This northeast facing glacier is wider than it is long relative to its flow direction and spans about 300 m in elevation with a median altitude of 2450 m. It ranks as a moderately sized glacier for this region, which contains the second highest concentration of glaciers in the U.S. Rocky Mountains.

Due to its position on the Continental Divide the glacier is influenced by both maritime and continental air masses. However, given its position on the western and predominantly windward side of the Continental Divide, Pacific storm systems dominate the weather. These bring heavy precipitation and moderate temperatures as warm, moist Pacific fronts collide with and lift over the Rocky Mountains. Temperature and precipitation patterns in northwest Montana are marked by strong altitudinal gradients. For valley sites at about 1000 m, mean temperatures for July, which is generally the warmest month of the year, are typically 15-17°C (59-63°F); they are roughly half that for mountain sites at 2500 m (Finklin, 1986). Annual precipitation averages 580 mm on the western and eastern edges of Glacier Park, but over 2500 mm at higher elevations in the Park's interior near the Continental Divide.

In 2005, the USGS Climate Change in Mountain Ecosystems (CCME) program established a glacier monitoring strategy in northwest Montana with the goal of assessing long-term changes to the region's glaciers. Through this monitoring program researchers also aimed to evaluate the hydrologic and ecologic effects of glaciers in Glacier National Park. Sperry Glacier was chosen as the benchmark study glacier due to its history of previous research, physical characteristics, and accessibility.

Research

Ablation stakes are used to measure the loss of seasonal snow on Sperry Glacier
Ablation stakes are used to measure the loss of seasonal snow on Sperry Glacier
Map showing the location of the Sperry Glacier

Sperry became the focus of extensive field research starting in 2005 as scientists employed standard glaciological methods (Ostrem and Brugman, 1991) to estimate glacier-wide seasonal and annual surface mass balances. Snow depths and densities are measured in the spring when the glacier's balance is at a maximum. Ablation stakes are also installed at this time and then checked periodically during the summer melt season with a final check in early autumn at the balance minima. With similar goals and methodologies, the Sperry Glacier mass balance project joined the established USGS Benchmark Program in 2013. The addition of Sperry to the long-established mass balance monitoring projects in Alaska and Washington will facilitate a broader understanding of glacier dynamics, hydrology, and glacier response to climate change.

Mass balance data summary

5 publications matching the specified parameters were found.

Clark, A. M., Fagre, D. B., Peitzsch, E. H., Reardon, B. A., and Harper, J. T., 2017, Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005-2015, Earth Syst. Sci. Data, 9, 47-61, doi:10.5194/essd-9-47-2017.
Available at: http://www.earth-syst-sci-data.net/9/47/2017/essd-9-47-2017.html

Clark, Adam M., Joel T. Harper, Daniel B. Fagre, 2015, Glacier-derived August runoff in northwest Montana, Arctic, Antarctic, and Alpine Research, Vol. 47, no. 1, p 1-16. doi: dx.doi.org/10.1657/AAAR0014-033.
Available at: http://www.bioone.org/doi/abs/10.1657/AAAR0014-033

Johnson, A., 1980, Grinnell and Sperry Glaciers, Glacier National Park, Montana: a record of vanishing ice, U.S.G.S. Professional Paper 1180. U.S. Dept. Interior, Washington, D.C., 29 p.
Available at: http://pubs.er.usgs.gov/publication/pp1180

Key, C. H., Fagre, D. B., and Menicke, R. K., 2002, Glacier retreat in Glacier National Park, Montana. Pages J365-J381 In Satellite Image Atlas of Glaciers of the World, Glaciers of North America - Glaciers of the Western United States. R. S. Williams and J. G. Ferrigno, (eds.) U.S. Geological Survey Professional Paper 1386-J. United States Government Printing Office, Washington D. C., USA.
Available at: http://pubs.usgs.gov/pp/p1386/

Reardon, B. A., J. T. Harper, and D. B. Fagre, 2008, Mass balance of a cirque glacier in the U.S. Rocky Mountains, Proceedings of the Mass Balance Measurement and Modelling Workshop, Skeikampen, Norway, 26-28 March 2008. Annals of Glaciology 50: A0741-5
Available at: http://www.nrmsc.usgs.gov/files/norock/products/GCC/Reardon_Proceedings_Norway_2008.pdf

Sperry Glacier weather station
Sperry Glacier weather station

In June 2006 the Sperry Glacier weather station (48° 37' 24.1932" N, 113° 45' 53.4347" W) was installed at an altitude of 2450 m on a rocky outcrop about 100 m from the western edge of the glacier. Sensors measured air temperature, wind speed and direction, incoming solar radiation, and relative humidity. It became apparent that the 2 m mast height was not sufficient as the station was buried every winter and typically did not melt out until June. In some years the sensors were damaged so severely by snowpack creep that they needed replacing. During years with exceptionally heavy snowfall, such as in 2011, the station did not melt out until late July. The station was abandoned in 2012 due to these issues and there are no data for that year. But in 2013, the station was re-installed and recorded data for most of the June through September ablation season. In September 2014 a new station was installed in the same location with a 4 m mast and fitted with new instruments including a net radiometer, a new power system, and satellite telemetry. The taller mast should keep the sensors above the snowpack surface during the winter allowing the station to remain operational year round.

This taller mast should keep sensors above snowpack to extend the station's data collection record
This taller mast should keep sensors above snowpack to extend the station's data collection record

There are complete records of daily average temperature for the months July and August 2006-2011 and 2013. Most of the ablation on the glacier occurs during these two summer months. For the period of record, the mean July-August daily average temperature was 9.7° C (50° F) with a maximum daily average of 19.1° C (66° F) and minimum of -2.1° C (28° F). Precipitation at the glacier has not been measured directly. Snowfall is the dominant form of precipitation and usually accumulates starting in September or October and continues through May or June. The nearest weather station with precipitation data is the Flattop SNOTEL located 25 km northeast of and 530 m lower than the Sperry station. Average yearly precipitation here from the years 1980-2010 was 1.70 m (67 in). Snowpack measurements made in June when the glacier is near peak accumulation reveal precipitation is likely much higher on the glacier. Values of 2.50 meters (98 in) of snow water equivalent to 3.00 m (118 in) are common. However the accumulation patterns on Sperry are not fully understood and it is unclear what percentage of these deep snow packs owe their existence to precipitation versus how much snow is transported onto the glacier by wind and avalanches.

Current data available from the Sperry weather station includes:

  • Air Temperature
  • Precipitation
  • Relative Humidity
  • Wind Speed
  • Wind Direction
  • Radiation

4 publications matching the specified parameters were found.

Brown, J., Harper, J., and N. Humphrey, 2010, Cirque glacier sensitivity to 21st century warming: Sperry Glacier, Rocky Mountains, USA. Global and Planetary Change, 74:91-98, doi: 10.1016/j.gloplacha.2010.09.001.
Available at: http://www.sciencedirect.com/science/article/pii/S0921818110001955

Clark, A. M., Fagre, D. B., Peitzsch, E. H., Reardon, B. A., and Harper, J. T., 2017, Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005-2015, Earth Syst. Sci. Data, 9, 47-61, doi:10.5194/essd-9-47-2017.
Available at: http://www.earth-syst-sci-data.net/9/47/2017/essd-9-47-2017.html

Clark, Adam M., Joel T. Harper, Daniel B. Fagre, 2015, Glacier-derived August runoff in northwest Montana, Arctic, Antarctic, and Alpine Research, Vol. 47, no. 1, p 1-16. doi: dx.doi.org/10.1657/AAAR0014-033.
Available at: http://www.bioone.org/doi/abs/10.1657/AAAR0014-033

Finklin, A.I., 1986, A climatic handbook for Glacier National Park-with data for Waterton Lakes National Park, General Technical Report INT-204, U.S.D.A. Forest Service, Ogden, UT. 55p.
Available at: http://www.fs.fed.us/rm/pubs_int/int_gtr204.pdf

Runoff from Sperry Glacier is broadly dispersed among numerous channels along the glacier's terminus
Runoff from Sperry Glacier is broadly dispersed among numerous channels along the glacier's terminus

At this time, stream discharge for Sperry Glacier is not measured. The glacier's broad expanse creates numerous discreet runoff streams which make gauging this glacier a challenge. Runoff data are not available for this glacier.

2 publications matching the specified parameters were found.

Clark, A. M., Fagre, D. B., Peitzsch, E. H., Reardon, B. A., and Harper, J. T., 2017, Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005-2015, Earth Syst. Sci. Data, 9, 47-61, doi:10.5194/essd-9-47-2017.
Available at: http://www.earth-syst-sci-data.net/9/47/2017/essd-9-47-2017.html

Clark, Adam M., Joel T. Harper, Daniel B. Fagre, 2015, Glacier-derived August runoff in northwest Montana, Arctic, Antarctic, and Alpine Research, Vol. 47, no. 1, p 1-16. doi: dx.doi.org/10.1657/AAAR0014-033.
Available at: http://www.bioone.org/doi/abs/10.1657/AAAR0014-033

Figures are not far from present day climate station location on Sperry Glacier.  Morton Elrod photo, 1909, GNP Archives.
Figures are not far from present day climate station location on Sperry Glacier. Morton Elrod photo, 1909, GNP Archives.

The glaciers of Glacier National Park have been the focus of visitor and scientific interest since before the park was established in 1910. Because it is relatively easy to access, Sperry Glacier has one of the most extensive records of historic data and measurement in the region. The earliest photo of the glacier dates back to 1894 and the earliest map was created in 1901. William Alden, a geologist for the USGS, explored the glacier and published the first scientific measurements and descriptions in the early 20th century (Alden, 1914; Alden, 1923). The glacier's retreat was documented by Dyson (1948) and the USGS and NPS conducted annual measurements of the glacier in the mid-20th century, including the installation of ablation stakes, measurements of flow speed and direction, and plane-table mapping that resulted in a detailed topographical map of the glacier with terminus locations from 1913-1969 (Johnson, 1980) (Reardon, et al, 2008). The progression of glacier retreat has been documented using satellite imagery and aerial photos (Key, et al., 2002), repeat photography, and annual GPS mapping of margins and terminus since 2003 by the USGS — CCME glacier monitoring program. Other parameters, such as depth measurement through the use of ice radar, GPS velocity measurements, and the determination of elevation profiles were included at the beginning of the monitoring program in 2005 in collaboration with Joel T. Harper of the University of Montana, Missoula.

Publications search

Data Summaries for Sperry Glacier

Time-Series Data: GNP glacier margins

5 publications matching the specified parameters were found.

Alden, W.C., 1914, Glaciers of Glacier National Park, U.S. Dept. Interior. Washington, D.C. 48 p.

Alden, W.C., 1923, Rate of movement in glaciers of Glacier National Park, Science, Vol. 57 no. 1470, p. 268.

Carrara, P.E., 1989, Late quaternary glacial and vegetative history of the Glacier National Park region, Montana, U.S.G.S Bulletin 1902, U.S. Dept. Interior, Washington, D.C. 64 p.
Available at: http://pubs.usgs.gov/bul/1902/report.pdf

Clark, A. M., Fagre, D. B., Peitzsch, E. H., Reardon, B. A., and Harper, J. T., 2017, Glaciological measurements and mass balances from Sperry Glacier, Montana, USA, years 2005-2015, Earth Syst. Sci. Data, 9, 47-61, doi:10.5194/essd-9-47-2017.
Available at: http://www.earth-syst-sci-data.net/9/47/2017/essd-9-47-2017.html

Dyson, J.L., 1948, Shrinkage of Sperry and Grinnell Glaciers, Glacier National Park, Montana, Geographical Review. 38(1): 95-103.
Available at: http://www.jstor.org/stable/210740?seq=1#page_scan_tab_contents

Sperry Glacier is the destination for this hiker, August 19, 2014.
Sperry Glacier is the destination for this hiker, August 19, 2014.
On Sperry Glacier for August visit to check ablation stakes, 2014.
On Sperry Glacier for August visit to check ablation stakes, 2014.
Snow cover at ablation stake #2 has entirely melted away by Aug. 19, 2014.  The gushing meltwater stream running past the stake indicates that further ablation (melt) is occurring on the glacier.
Snow cover at ablation stake #2 has entirely melted away by Aug. 19, 2014. The gushing meltwater stream running past the stake indicates that further ablation (melt) is occurring on the glacier.
Sperry Glacier is blanketed in meters of snow when researchers visit the glacier June to install ablation stakes.  June 12, 2014.
Sperry Glacier is blanketed in meters of snow when researchers visit the glacier June to install ablation stakes. June 12, 2014.
The weather station at Sperry Glacier provides site-specific data for mass balance research.  The recession of Sperry Glacier has exposed layers of sedimentary rock.
The weather station at Sperry Glacier provides site-specific data for mass balance research. The recession of Sperry Glacier has exposed layers of sedimentary rock.
Researcher traverses Sperry Glacier while collecting mass balance data.  August 30, 2011.
Researcher traverses Sperry Glacier while collecting mass balance data. August 30, 2011.
This late August photo shows glacial ice exposed by melting snow. August 30, 2011.
This late August photo shows glacial ice exposed by melting snow. August 30, 2011.
Nearing the upper reaches of the accumulation zone of Sperry Glacier, June 24, 2005.
Nearing the upper reaches of the accumulation zone of Sperry Glacier, June 24, 2005.
Evening light on the layers of sedimentary rock and upper portion of Sperry Glacier.
Evening light on the layers of sedimentary rock and upper portion of Sperry Glacier.
Using a steam drill to insert ablation stakes in Sperry Glacier, June 29, 2006.
Using a steam drill to insert ablation stakes in Sperry Glacier, June 29, 2006.
Sperry Glacier, 1913, Alden, GNP Archives
Sperry Glacier, 1913, Alden, GNP Archives
Sperry Glacier, 2008, McKeon, USGS
Sperry Glacier, 2008, McKeon, USGS

In 1913, Sperry Glacier spanned across the entire basin and the glacier's terminus was recorded at over 150 ft. tall. Contemporary images show how the glacier has receded and separated into fragments.

Sperry Glacier, circa 1920, Elrod, K. Ross Toole Archives, U of M
Sperry Glacier, circa 1920, Elrod, K. Ross Toole Archives, U of M
Sperry Glacier, 2008, McKeon, USGS
Sperry Glacier, 2008, McKeon, USGS

Repeating Elrod's photograph from the same photo point was impossible since he shot from the elevated perspective of the glacier's surface. The terminus of the glacier has retreated beyond the field of view, but these images give a sense of the glacier's extent and mass early in the 20th century.

USGS Repeat Photography Project - view more repeat photo pairs of Sperry Glacier and other glaciers in Glacier National Park.

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