HR: 0800h
AN: H21A-1314    [Abstracts]
TI: Field and Satellite Observations of Supra-Glacial Lake Fluctuations on the Baltoro Glacier, Karakoram Himalaya, Pakistan
AU: * Bishop, M P
EM: mpbishop@mail.unomaha.edu
AF: Department of Geography and Geology, University of Nebraska-Omaha 6001 Dodge Street, Omaha, NE 68182 United States
AU: Shroder, J F
EM: jshroder@mail.unomaha.edu
AF: Department of Geography and Geology, University of Nebraska-Omaha 6001 Dodge Street, Omaha, NE 68182 United States
AB: Alpine glaciers are retreating and downwasting in many mountain environments. Remote sensing and field studies of glacier fluctuations indicate increases in meltwater production and the development of ablation valley, supraglacial and proglacial lakes. The occurrence and development of glacial lakes are related to climate change, although dynamic processes affecting lake development are complex and highly variable. As part of the Global Land Ice Measurements from Space (GLIMS) project, we conducted fieldwork on the Baltoro Glacier in the summer of 2005, and measured and characterized various aspects of the glacier surface. We also developed an object-oriented approach for assessing supraglacial lakes using ASTER imagery. Change detection studies were conducted using ASTER imagery from the 2000-2004 time period. Ground photography and image analysis revealed significant water-level and surface-area fluctuations at a variety of time scales. Diurnal variations in the water level of a large supraglacial lake between the tributary Liligo Glacier and the Baltoro Glacier was measured to be 1-2 m. Over a 1-2 week period, the lake level dropped 10 m and was draining down an ice-bound swallow hole. Lake-level decline was measured at ~20-25 cm hr^-1. Image analysis results show a significant increase in the frequency and size of supraglacial lakes from 2000 to 2004. These results support field observations that indicate that the Baltoro glacier is rapidly downwasting. Break-out flooding also explains why the glacier does not exhibit any terminal moraines.
DE: 0720 Glaciers
DE: 1621 Cryospheric change (0776)
DE: 1827 Glaciology (0736, 0776, 1863)
DE: 1855 Remote sensing (1640)
SC: Hydrology [H]
MN: Fall Meeting 2005