National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Change in Glacial Extent at Mount Rainier National Park from 1896 to 2015 Natural Resource Report NPS/MORA/NRR—2017/1472 ON THIS PAGE Extents of perennial snow, snowfields, and glaciers on Mount Rainier in 2015 from this study Courtesy of the National Park Service ON THE COVER Oblique aerial photo of the south face of Mount Rainier showing the Kautz, Success, Van Trump, Wilson, and Nisqually Glaciers. Photo taken 11/28/2015 at 5:00 PM. Photograph courtesy of Michael Gauthier and used with expressed permission. Change in Glacial Extent at Mount Rainier National Park from 1896 to 2015 Natural Resource Report NPS/MORA/NRR—2017/1472 Scott R. Beason National Park Service Mount Rainier National Park 55210 238th Ave E Ashford, WA 98304 June 2017 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service. The series supports the advancement of science, informed decision-making, and the achievement of the National Park Service mission. The series also provides a forum for presenting more lengthy results that may not be accepted by publications with page limitations. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received informal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data. Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This report is available in digital format from the Mount Rainier National Park website and the Natural Resource Publications Management website. To receive this report in a format that is optimized to be accessible using screen readers for the visually or cognitively impaired, please email [email protected]. Please cite this publication as: Beason, S. R. 2017. Change in glacial extent at Mount Rainier National Park from 1896 to 2015. Natural Resource Report NPS/MORA/NRR—2017/1472. National Park Service, Fort Collins, Colorado. NPS 105/138956, June 2017 ii Contents Page Figures................................................................................................................................................... iv Tables ..................................................................................................................................................... v Appendixes ............................................................................................................................................ v Plates ..................................................................................................................................................... vi Conversion Factors ............................................................................................................................... vi Glossary ................................................................................................................................................ vi Abstract ...............................................................................................................................................viii Acknowledgements .............................................................................................................................viii Introduction ............................................................................................................................................ 1 Study Area ............................................................................................................................................. 3 Previous Research .................................................................................................................................. 4 Methods .................................................................................................................................................. 5 Glacier extents (2015) and comparison with previous inventories ................................................ 5 Debris cover in 2015 ...................................................................................................................... 7 Errors and accuracy of 2015 inventory .......................................................................................... 7 Current Glacier Statistics ................................................................................................................ 8 Results .................................................................................................................................................. 10 2015 Glacier Extents .................................................................................................................... 10 2015 Debris Cover ........................................................................................................................ 11 Extent comparison over time ........................................................................................................ 14 Changes in Extent by Aspect ........................................................................................................ 23 Glacier Statistics ........................................................................................................................... 24 Literature Cited .................................................................................................................................... 27 iii Figures Page Figure 1. Mount Rainier National Park extent and study area. ............................................................. 3 Figure 2. Extent and dates of data sources used in mapping of glacial extents for the 2015 season. ........................................................................................................................................... 6 Figure 3. Extent of perennial snow and glaciers at Mount Rainier in 2015, based on data in Table 2. ............................................................................................................................................ 10 Figure 4. Extents of glacial debris cover and exposed ice on glaciers at Mount Rainier in 2015, based on data from Table 3.. ...................................................................................................... 12 Figure 5. Overall change in surface area for all glaciers at Mount Rainier from 1896- 2015, based on data in Table 4. ............................................................................................................ 14 Figure 6. Change in surface area of glaciers from 1896 to 2015 that had a 2015 extent greater than five square kilometers, based on data in Table 4. ............................................................ 20 Figure 7. Change in surface area of glaciers from 1896 to 2015 that had a 2015 extent between 1 and 5 square kilometers, based on data in Table 4. ............................................................ 21 Figure 8. Change in surface area of glaciers from 1896 to 2015 that had a 2015 extent less than 1 square kilometer, based on data in Table 4. ....................................................................... 22 Figure 9. Change in extent of glaciers by aspect from 1896 to 2015 at Mount Rainier, based on data from Table 7. ................................................................................................................. 23 iv Tables Page Table 1. Image data sources acquired and analyzed for this study. See Figure 2 for map of coverage. ............................................................................................................................................ 5 Table 2. Extent of glacial ice, snowfields, and perennial snow in 2015 at Mount Rainier. ................ 11 Table 3. Extent of debris-covered area on glaciers in 2015 at Mount Rainier. ................................... 13 Table 4. Comparison of extents of glaciers at Mount Rainier over time (excluding unnamed perennial ice/snow fields). .................................................................................................... 15 Table 5. Total area change in extent between inventory periods for each glacier at Mount Rainier. Listed units are in square kilometers (km2). ........................................................................... 16 Table 6. Total