Change in glacier volume between on M t H ood and M t R ainier

Transcription

1 Change in glacier volume between on M t H ood and M t R ainier Chris K irkland & T anja H opmans G eography Digital T errain Analysis

2 Introduction & Background - G laciers provide tangible evidence of climate change and act as a measureable and quantifiable source of the effects of rising temperatures and changes with weather patterns - U se of historic and current D EM s to measure and quantify ice volume depletion and use of models to calculate rate of retreat and draw correlations to influential factors - M ultiple studies have shown that D EM s can be used to accurately quantify glacial ice loss and glacier surface elevation change ( Si sson 2011& M cn abb2012)

3 D atasets 1:100,000 Scale - All North American Glacier Outlines DRG / DLG / USGS Topo Map derived Limited accuracy at large scale and from area to area 1:5,000 Scale - Mount Rainier Glacier Outline file Lidar derived, higher accuracy for Rainier study area required due to resolution Historic DEM for Mount Rainier Study Area 10 meter horizontal and 1meter vertical accuracy 2006 DEM for Mount Rainier Study Area 1meter horizontal and 1meter vertical accuracy 1990 Historic DEM for Mount Hood Study Area 30 meter horizontal and 1meter vertical accuracy 2010 DEM for Mount Hood Study Area 3 foot horizontal and 1foot vertical accuracy

4 Mount Hood Study A rea

5 Mount Rainier Study A rea

6 M ethods & T ools

7 M ethods & T ools M osaic DEM s together to create seamless study area Use glacier shapefile to extract / clip out data for all glaciers as well as individual glaciers Use Aggregate tool to convert to matching linear units between DEM s Use Raster snap function to align datasets Use Cut Fill to analyze volume increase, decrease and sum Use Raster calculator to determine height change over glacier surface Use Raster calculator to elevation units Use summary statistics and attribute table statistics to determine volume sum, increase, decrease and area

8 Results for Mount Hood Study Area Glacier Volume decrease (km 3 ) Volume increase (km 3 ) Net Change (km 3 ) Area (km 2 ) aspect Eliot North and east facing Sandy West and north facing Newton East facing Clark Zigzag e West and south facing Coe North facing Reid e West and north facing

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10 Results for Mount Rainier Study Area Volume Total for Sisson variation due to original DEM error factor

11 Aspect Mount Rainier Study Area

12 Results for M ount R ainier Study A rea H eight C hange

13 Limitations and Further Research T he accuracy of the historic 10m D EMs of M ount R ainier is uncertain since metadata did not include accuracy or error definition or even exact year of acquisition A ccuracy of 1:100,000 k N orth A merican G lacier outline shapefile Accuracy of 30 meter D EM and omission of surface details in dataset L imited availability of temporal datasets to create multiple analyses and make comparisons Possible use of oldest available / accurate aerial photographs from specific years to create additional historic DEMs

14 1:100,000 k G lacier O utline Shapefile M isalignment Carbon G lacier M ount R ainier

15 Sources: P. Peduzzi, C. H erold, and W. Silverio. A ssessing high altitude glacier thickness, volume and area changes using field, G I S and remote sensing techniques: the case of N evado Coropuna (Peru) 23 A ugust 2010 T.W. Sisson1*, J.E. R obinson1*, and D.D. Swinney2* Whole-edifice ice volume change A.D to 2007/2008 at M ount R ainier, W ashington, based on LiDAR surveying. 1U.S. Geological Survey, 345 Middlefield R oad, Menlo Park, California 94025, USA 2 N ational Park Service, M ount R ainier N ational Park, A shford, W ashington 98304, U SA A ndrew G. Fountain, M atthew H offman, K eith Jackson, H assan Basagic, T homas N ylen, and D avid Percy D igital outlines and T opography of the A merican W est. USGS. R eston, V irginia: 2007 M ichael L eslie H ekkers. Climatic and Spatial V ariations of M ount R ainier s G laciers for the L ast 12,000 Years. Portland State University T homas H. N ylen. Spatial and T emporal V ariations of G laciers ( ) on Mt. R ainier and the relation with climate. Portland State University Frank D. G ranshaw. G lacier Change in the N orth Cascades N ational Park Complex, W ashington State U SA, 1958 to Portland State University R.W. M cn abb et al. U sing surface velocities to calculate ice thickness and bed topography: a case study at Columbia G lacier, A laska, U SA. Journal of Glaciology, Vol. 58, No. 212, K arl Lillquist, K aren W alker. H istoric Glacier and climate fluctuations at Mount H ood, Oregon. Arctic, Antarctic, and Alpine R esearch, vol.38,no.3, 2006, pp