HR: 11:35h
AN: C42A-06    [Abstracts]
TI: Uses of Several Photographic Methods to Detect Changes of Glaciers in Arctic Alaska
AU: * Nolan, M
EM: matt.nolan@uaf.edu
AF: University of Alaska Fairbanks, 455 Duckering Bldg, Fairbanks, AK 99775 United States
AU: Takahashi, S
EM: shuhei@mail.kitami-it.jp
AF: Kitami Institute of Technology, Koen-cho 165 , Kitami, 090-0807 Japan
AB: We have employed several photographic methods to detect changes on glaciers in Arctic Alaska. On Okpilak and McCall Glaciers in the eastern Brooks Range, we have re-occupied photo-locations from 1906 and 1958 respectively. These photos unambiguously document that a large loss of ice mass has been on-going here over the past 100 years. The Okpilak Glacier photos also unambiguously reveal that retreat from the most recently exposed moraines did not begin until near the turn of the century, supporting lichenometric evidence that the change in weather patterns that marked the end of the Little Ice Age here occurred sometime around 1890. A time-series of photos from this photo-site since 1906 reveals the influence of glacier geometry on volume loss rates. Comparing these photos with modern survey data has also allowed us to better quantify the ice loss observed. On McCall Glacier, we have employed time-lapse photography in several ways. By installing a camera on a ridge high above the glacier, we can watch the snow-line move up-glacier in summer. By placing a camera in the accumulation area in front of a large ruler, we can record the rate of snow accumulation throughout the year. By placing a camera in front of our weather stations located on the glacier surface, we can both improve our interpretations of the weather data as well as help troubleshoot the causes for equipment malfunctions. Because shading plays such an important role in patterns of surface mass balance in these steep mountain valleys, we have used both optical and infrared time-series of photos to document both shading and the resulting impact on surface temperature within the valley. We are also using these time-series to help validate models of surface energy balance that incorporate shading.
DE: 3349 Polar meteorology
DE: 3394 Instruments and techniques
DE: 1827 Glaciology (1863)
DE: 1894 Instruments and techniques
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting