WATER, ICE, AND METEOROLOGICAL MEASUREMENTS AT SOUTH CASCADE GLACIER, WASHINGTON, BALANCE YEARS 2004 AND 2005 Scientific Investigations Report 2007–5055 U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Cover: Photograph of South Cascade Glacier, Washington, from the north-northwest, August 24, 2005 (photograph by Willian Bidlake, U.S. Geological Survey). Water, Ice, and Meteorological Measurements at South Cascade Glacier, Washington, Balance Years 2004 and 2005 By William R. Bidlake, Edward G. Josberger, and Mark E. Savoca Scientific Investigations Report 2007–5055 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DIRK KEMPTHORNE, Secretary U.S. Geological Survey Mark D. Myers, Director U.S. Geological Survey, Reston, Virginia: 2007 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Bidlake, W.R., Josberger, E.G., and Savoca, M.E., 2007, Water, ice, and meteorological measurements at South Cascade Glacier, Washington, balance years 2004 and 2005: U.S. Geological Survey Scientific Investigations Report 2007-5055, 69 p. iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Previous Work .......................................................................................................................................3 Purpose and Scope ..............................................................................................................................3 Description and Climate of Study Area .............................................................................................3 Study Methods ...............................................................................................................................................5 Meteorological and Streamflow Measurements ............................................................................5 Glacier Mass Balance and Related Principles ................................................................................6 Glaciological Measurements ..............................................................................................................8 Photogrammetric Measurements and Glacier Mapping ...............................................................8 Results and Discussion .................................................................................................................................8 Water Year 2004 Meteorological and Streamflow Data .................................................................9 Water Year 2005 Meteorological and Streamflow Data ...............................................................27 2004 Winter Balance ..........................................................................................................................42 2004 Net Balance ................................................................................................................................49 2004 Summer and Annual Balances ................................................................................................54 2005 Winter Balance ..........................................................................................................................55 2005 Net Balance ................................................................................................................................61 2005 Summer and Annual Balances ................................................................................................66 Some Sources of Mass-Balance Errors .........................................................................................66 Terminus Retreat, Glacier Area, and Equilibrium Line Altitude ...................................................66 Summary and Conclusions .........................................................................................................................67 Acknowledgments .......................................................................................................................................67 References Cited..........................................................................................................................................68 iv Figures Figure 1. Map showing location of the study area, South Cascade Lake Basin, Washington ……………………………………………………………………… 2 Figure 2. Map showing South Cascade Glacier and vicinity, Washington ………………… 4 Figure 3. Graphs showing hourly average air temperature at selected sites in and near South Cascade Lake Basin, Washington, water year 2004 ……………………… 15 Figure 4. Graphs showing air temperature recorded at 10-minute intervals at three selected locations on South Cascade Glacier, Washington, April–September 2004 ……………………………………………………………………………… 16 Figure 5. Graphs showing hourly average wind speed and incoming solar radiation at the Hut, 1,842 meters altitude, near South Cascade Lake Basin, Washington, water year 2004 …………………………………………………………………… 20 Figure 6. Graphs showing stage of Middle Tarn and Salix Creek, daily average runoff from Middle Tarn and Salix Creek basins, and precipitation (gage catch) at the Salix Creek gaging station, Washington, water year 2004 …………………… 24 Figure 7. Graphs showing hourly average air temperature at selected sites in and near South Cascade Lake Basin, Washington, water year 2005 ……………………… 33 Figure 8. Graphs showing air temperature recorded at 10-minute intervals at three selected locations on South Cascade Glacier, Washington, May–September 2005 ……………………………………………………………………………… 34 Figure 9. Graphs showing hourly average incoming solar radiation at the Hut, 1,842 meters altitude, near South Cascade Lake Basin, Washington, water year 2005 … 38 Figure 10. Graphs showing stage of Middle Tarn and Salix Creek, daily average runoff from Middle Tarn and Salix Creek basins, and precipitation (gage catch) at the Salix Creek gaging station, Washington, water year 2005 …………………… 40 Figure 11. Map showing partial and complete outlines of South Cascade Glacier, Washington, 2003 and 2004, locations of 2004 measurement sites for snow depth and density, and locations of 2004 ablation stakes ………………………… 43 Figure 12. Schematic diagram showing variations of surface height and selected thicknesses of materials gained and lost in vicinity of stake 1-04 during balance years 2002 to 2005 ……………………………………………………… 45 Figure 13. Graph showing snow water equivalent as it varied with altitude on South Cascade Glacier, Washington, April 24–26, 2004 ………………………………… 46 Figure 14. Map showing 2004 altitude grid for South Cascade Glacier, measured from variously dated vertical aerial photographs ……………………………………… 47 Figure 15. Mosaic image of South Cascade Glacier, Washington, constructed from vertical photographs, September 10, 2004 ………………………………………… 52 Figure 16. Graph showing net balance as it varied with altitude on South Cascade Glacier, Washington, balance year 2004 ………………………………………… 53 Figure 17. Graph showing summer balance of South Cascade Glacier as it varied with average air temperature at the Hut, 1,842 meters altitude, near South Cascade Lake Basin, Washington, June–September …………………………… 54 Figure 18. Map showing partial and complete outlines of South Cascade Glacier, Washington, 2004 and 2005, locations of 2005 measurement sites for snow depth and density, and locations of 2005 ablation stakes ………………………… 56 Figure 19. Graph showing snow water equivalent as it varied with altitude on South Cascade Glacier, Washington, April 20–21, 2005 ………………………………… 58 v Figures—Continued Figure 20. Map showing 2005 altitude grid for South Cascade Glacier, measured from variously dated vertical aerial photographs ……………………………………… 60 Figure 21. Graph showing net balance as it varied with altitude on South Cascade Glacier, Washington, balance year 2005 ………………………………………… 63 Figure 22. Graph showing cumulative net balance at South Cascade Glacier, Washington, balance years 1953–2005 …………………………………………… 64 Figure 23. Mosaic image showing South Cascade Glacier, Washington, constructed from vertical photographs, September 21, 2005 …………………………………… 65 Tables Table 1. Daily maximum, minimum, and average of hourly average air temperature at the Hut, 1,842 meters altitude, near South Cascade Lake Basin, Washington, water year 2004 …………………………………………………………………… 9 Table 2. Daily maximum, minimum, and average of hourly average air temperature at the Middle Tarn gaging station, 1,631 meters altitude, Middle Tarn Basin, Washington, water year 2004 …………………………………………………… 11 Table 3. Daily maximum, minimum, and average of hourly average air temperature at the Salix Creek gaging station, 1,587 meters altitude, Salix Creek Basin, Washington, water year 2004 …………………………………………………… 13 Table 4. Daily maximum, minimum,