Mount Rainier, Washington Portland State University GEOG 592 Spring 2014
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A Slow End: Tracking Glacier Loss on Mount Rainier, Washington Portland State University GEOG 592 Spring 2014 Jonathan Skloven-Gill and Marilyn Daum Seattle How to Calculate Glacier Length? Glacial ice is the largest reservoir of freshwater on Predicted Change in Mt. Rainier's Glaciers over Time Hydrology Flow Length Minimum Bounding Rectangle Length Tacoma Puyallup - White Applying NCAR's moderate A1B climate change scenario earth, and Mount Rainier is the most heavily glaci- generally shorter longer and closer match to other sources Olympia to Oerleman's model for glacier length change ated peak in the lower 48 states(1). We have heard Nisqually Centralia that climate change is shrinking glaciers, but what Mount Rainier Glaciers as of 2006 Percent remaining in 2050 Percent Remaining in 2099 Impacted Cities does this mean for Mt. Rainier's glaciers during the Washington Counties Pop per Cowlitz SQMile next 50 or 100 years? Specically, what is the risk >474 of losing the freshwater supply from Mt. Rainier's <24.5 Longview Watersheds Kilometers . 010 20 40 60 0% 0% glaciers? 0% 0% 0% 0% Why Mt. Rainier’s 45% 0% 0% Our investigation includes 3 approaches to analyz- 79% 12% 0% 78% Glaciers Matter 0% 0% 10% ing glacial recession. Using one of these, a signi- $ 60% 0% 0% 0% 0 1 2 3 4 24% cant relationship between glacier length and Correlation r=0.95, p-value=0.000 25% 76% 0% 0% Kilometers Projection: NAD 1927 UTM Zone 10 0% 0% 67% 0% 0% 0% 50% 0% 0% 0% long-term temperature changes, we present a plau- 0% 0% 0% 0% 55% 0% Fitted Line Plot 0% Hydrology Flow Length = - 235.3 + 0.9981 Bounding Rectangle Length 0% 75% 44% 0% sible future scenario based on moderate climate 75% 33% 0% 0% 0% 9000 0% S 820.842 70% R-Sq 90.2% 56% 0% (3) 8000 0% 0% 67% 0% change . R-Sq(adj) 90.0% 67% 0% 0% 0% 9% 25% 0% 7000 0% 13% 0% 0% 0% 0% Pearson 0% 0% 6000 correlation 0% 0%0% Correlated Temporal Variables Calculated Glacial Desiccation coefficient 0% 0%0% Glacial Volume Loss 5000 r = 0.95 Change in Temperature Change in Precipitation Solar Duration Glacial Thinning p-value = 0.000 6 3 10 m Degrees Celsius Millimeters Hours / Year Height in Meters 4000 -11.6 - -3.29 1.80 - 1.90 Carbon 90 - 109 2155 - 2486 Contour $ 98.9214 3000 -3.28 - 0.00 1.91 - 1.97 110 - 123 2487 - 2845 2100m Winthrop 0.01- 10.1 1.98 - 2.02 124 - 131 2846 - 3170 2000 Hydrology Flow Length Projection: NAD 1927 UTM Zone 10 East 0 42 Flett 10.2 - 26.3 2.03 - 2.09 132 - 135 3171 - 3379 0 West -30.9459 1000 Flett 26.4 - 42.7 2.10 - 2.15 136 - 140 3380 - 3622 Russell Kilometers North 42.8 - 83.4 2.16 - 2.23 141 - 147 3623 - 3934 0 Mowich Inter Emmons 10000 2000 3000 4000 5000 6000 7000 8000 9000 Edmunds Recession Analysis Liberty Gap Bounding Rectangle Length South Fryingpan Mowich (4) Puyallup Ohanapecosh We applied an existing model developed by Johannes Oerlemans to estimate changes in the length of Mt. Rainier's glaciers Summit Name Length (Meters) Aspect Tahoma Whitman Ingraham-Cowlitz Carbon Glacier 8450.716 North based on long-term temperature changes. Oerleman's model comes from his analysis of 48 glaciers around the world receding South Tahoma South Van StevensIngraham Cowlitz East Flett Glacier 830.539 North Williwakas PyramidSuccessKautz Trump Paradise Muir Nisqually-Wilson Snoweld Edmunds Glacier 2506.334 West from 1850 onward. He concludes there is an average of 2 km recession per year for a temperature change of 1 degree K, over a N 0 2 4 8 Kilometers Emmons Glacier 7204.868 NorthEast Fryingpan Glacier 3319.733 NorthEast period of 94 years. Based on his detailed results, we used a temperature-based recession factor of 21.10501030 meter per year Ingraham-Cowlitz Glacier 7133.678 East Volume/Thickness Analysis Inter Glacier 1723.257 NorthEast per degree K in our model. Monitoring and calculating area and volume on alpine glaciers is fraught with limitations and the Kautz Glacier 4401.837 South To calculate glacier length, we investigated two alternatives: the length of the minimum bounding rectangle for each glacier Liberty Gap Glacier 2597.644 North possibility for errors. 1986 marked the rst volume calculations by Driedger and Kennard, Muir Snoweld 1850.982 South polygon and the upstream ow length from a hydrology analysis. Though both yielded similar results (Pearson correlation co- Nisqually-Wilson Glacier 6350.873 South 3 estimating 4.42 km of snow and ice in 1970 on Mount Rainier using radar and 1970 contour N North Mowich Glacier 4698.779 NorthWest ecient = 0.95, p-value = 0.000), the former was chosen as the best t, as its results were both longer and more consistent with Kilometers Ohanapecosh Glacier 2482.419 East (2) 0 2 4 8 Net Volume Change (1,5) maps . Much like Sisson in 2011, we attempted to redraw the areas bounds using the 1m 16bit Contour Volume Gain Paradise Glacier 2083.261 SouthEast lengths reported in other resources . 2100m Volume Loss Puyallup Glacier 4240.209 West LiDAR hillshade alone. Because of the diculty and limited knowledge of glaciology, we only Pyramid Glaciers 2123.019 South This model was applied to historical Nisqually glacier recession data for the period 1868 to 1960 from Mount Rainier National analyzed the 29 named glaciers of the recognized 49 perennial snow/ice elds that are on Rainier. Russell Glacier 3301.068 NorthEast Park (MORA)(6). The observed recession was 1.6km, and the model-predicted recession was 1.5km, which is well within the 15% South Ingraham-Cowlitz Glacier 5414.88 East Straight away, we began to see signicant dierences from the 2011 study. South Mowich Glacier 5860.147 West stated error for the model. We chose this model and applied it to all the glaciers on Mt. Rainier for the periods 2006 to 2050 South Tahoma Glacier 5848.794 SouthWest 2 2 We measured 84.9 km of glacier cover, Sisson calculated 93.3 km of total perennial snow and ice Stevens Glacier 1170.132 West and 2006 to 2099. Average annual temperatures for each year were acquired from NCAR as point shapeles. Using cokriging, 2 Success Glacier 1819.806 South cover. Utilizing the 3D Analysis toolset in ArcGIS, we calculated a 3D surface area of 94.1 km Summit Glacier 663.349 East these were combined with the DEM to yield temperature surfaces. Zonal statistics provided the mean temperature for each Tahoma Glacier 7755.577 West across the same shapeles using the 10m 1970 DEM. Van Trump Glacier 1825.598 South glacier. We used both the same dierencing method as Sisson and the 3D Analyst tool “Cut-Fill” to West Flett Glacier 920.09 North This model was further used to estimate when the glaciers on Mt. Rainier might disappear, based on an exponential regression Whitman Glacier 3032.225 SouthEast calculate the volume change between the 1970 and 2011 DEMs, maintaining a 10m resolution as Williwakas Glacier 611.451 SouthEast analysis (recession = 4.4706 * temp change^1.6377, R² = 0.9732) to smooth the predicted yearly changes in temperature. Winthrop Glacier 8195.913 NorthEast opposed to resampling to 100m(2). Both methods resulted in identical output. Ultimately we 3 3 ArcGIS Model Builder Method: found a total volume loss of 0.47 km . Sisson calculated 0.56 km across all the same glaciers using Regression Analysis Linear Correlations the 2008 LiDAR. Despite using the same method, our results are varyingly dierent across the Variable Thickness Loss Recession We ran ordinary least squares and exploratory regression analysis with calculated yearly length changes for up to 10 of Solar Pearson Corr. -0.067 n/a board. We attribute this random, gross dierence to our conservatively digitized shapeles. We the glaciers on Mt. Rainier, for most of the years between 1919 and 1991. We also ran the same analyses for the volume Exposure Sig. 0.661 Pearson Corr. -0.061 n/a believe it nearly impossible that such volumetric dierences could occur over a 3 year span. Precipitation ArcGIS Model Builder Method: changes of 29 glaciers over a 44 year span. Sig. (2-tailed) 0.691 In spite of these errors, we were still able to visually produce nearly identical visual outputs as Pearson Corr. -0.04 0.363 The concepts behind this approach came from Nylen’s master’s thesis and Sisson’s 2011 Geology article. Time-based pre- Temperature Sisson. Using the same data generation as the recession analysis, we were able to visually see Sig. (2-tailed) 0.793 0.0004 dictor variables included temperatures, precipitation, and carbon dioxide levels. Geomorphological predictor variables Pearson Corr. -0.186 n/a variable correlation. The most dramatic is the nearly uniform equilibrium elevation at 2100m. Surface Area included aspect (transformed, then averaged for the glacier), slope (mean), elevation (min, max and mean), length, and Sig. (2-tailed) 0.22 It is our hope that with the increasing use of LiDAR, more precise measurements consisting of Mean Pearson Corr. -0.506 n/a area. This analysis did not yield a usable model for predicting length or volume change. However, correlation analysis Elevation Sig. (2-tailed) 0 shorter time-frames can become regular. Over all we saw the same trends and anomalies as the (6) using this data and the data from the MORA reports indicates there is a signicant correlation between glacier change CO2 (redundant Pearson Corr. n/a 0.621 2011 research report with respect to volume change on Mount Rainier.