HR: 0830h
AN: C11C-0851    [PDF]
TI: Investigation of Subglacial and Englacial Hydrology Using Borehole Slug Tests; Bench Glacier, Alaska
AU: * Shaha, J M
EM: jmshaha@uwyo.edu
AF: Dept. of Geology and Geophysics, University of Wyoming, P.O. Box 3006, Laramie, WY 82071-3006 United States
AU: Harper, J T
EM: joelh@uwyo.edu
AF: Dept. of Geology and Geophysics, University of Wyoming, P.O. Box 3006, Laramie, WY 82071-3006 United States
AU: Humphrey, N F
EM: neil@uwyo.edu
AF: Dept. of Geology and Geophysics, University of Wyoming, P.O. Box 3006, Laramie, WY 82071-3006 United States
AU: Pfeffer, W T
EM: Tad.Pfeffer@Colorado.EDU
AF: INSTAAR, University of Colorado, Campus Box 450, Boulder, CO 80309-0450 United States
AB: Slug tests have long been used to determine the hydraulic conductivity of aquifer formations in the immediate vicinity of monitoring wells. However, slug tests have rarely been used to help determine englacial and subglacial hydrological characteristics. A series of slug tests were performed on Bench Glacier, Alaska in order to characterize the subglacial and englacial hydrology. A total of 16 slug tests were performed over a period of one week in early June 2002, with an additional 20 slug tests performed over a period of 10 days in June 2003. The slug tests were performed at various times of the day in boreholes drilled to the bed of the glacier. During the 2002 field season, water levels were recorded in the slug hole and an adjacent hole approximately 10 meters away. In 2003, water levels were recorded in the slug hole and 5 adjacent holes (within a grid of 16 boreholes) located between 20 and 60 meters away. Responses to the slug of water varied from an overdamped, slow drain to an underdamped, oscillation of the borehole water level. Modeling of the amplitude and frequency for the underdamped response reveals information on the structure of the subglacial and englacial drainage systems, as well as provides constraints on the amount of water in the system. Analysis of the slug tests within the grid shows both temporal and spatial changes in the response and thus the system, providing insight into the development of the subglacial and englacial hydrologic systems.
DE: 1827 Glaciology (1863)
DE: 1829 Groundwater hydrology
DE: 1863 Snow and ice (1827)
DE: 1894 Instruments and techniques
SC: Cryosphere [C]
MN: 2003 Fall Meeting