PP11B-2226
A Survey of Spatial and Seasonal Water Isotope Variability on the Juneau Icefield, Alaksa
Monday, 14 December 2015
Poster Hall (Moscone South)
Donovan Dennis1, Austin Carter2, Anna E Clinger2, Olivia L Eads3, Sarah Gotwals4, Jeffrey Gunderson5, Andrew E Hollyday6, Eric S Klein7, Bradley R Markle8 and Jolon R Timms9, (1)Occidental College, Los Angeles, CA, United States, (2)University of Michigan, Ann Arbor, MI, United States, (3)University of Cincinnati, Cincinnati, OH, United States, (4)Macalester College, St. Paul, MN, United States, (5)College of Wooster, Wooster, OH, United States, (6)Middlebury College, Middlebury, VT, United States, (7)University of Alaska Anchorage, Anchorage, AK, United States, (8)University of Washington Seattle Campus, Seattle, WA, United States, (9)Reed College, Portland, OR, United States
Abstract:
The depletion of stable oxygen-hydrogen isotopes (δ18O and δH) is well correlated with temperature change, which is driven by variation in topography, climate, and atmospheric circulation. This study presents a survey of the spatial and seasonal variability of isotopic signatures on the Juneau Icefield (JI), Alaska, USA which spans over 3,000 square-kilometers. To examine small scale variability in the previous year’s accumulation, samples were taken at regular intervals from snow pits and a one square-kilometer surficial grid. Surface snow samples were collected across the icefield to evaluate large scale variability, ranging approximately 1,000 meters in elevation and 100 kilometers in distance. Individual precipitation events were also sampled to track percolation throughout the snowpack and temperature correlations. A survey of this extent has never been undertaken on the JI. Samples were analyzed in the field using a Los Gatos laser isotope analyzer. This survey helps us better understand isotope fractionation on temperate glaciers in coastal environments and provides preliminary information on the suitability of the JI for a future ice core drilling project.
