HR: 0800h
AN: C31B-0323    [Abstracts]
TI: Borehole Optical Stratigraphy and Neutron Scattering Density Measurements at Summit, Greenland
AU: * Hawley, R L
EM: bo@u.washington.edu
AF: Department of Earth and Space Sciences, 310 Condon Hall, University of Washington, Seattle, WA 98195 United States
AU: Morris, E M
EM: emmo@nerc-bas.ac.uk
AF: Scott Polar Research Institute, University of Cambridge, Lensfield Road, Cambridge, CB2 1ER United Kingdom
AU: Waddington, E D
EM: edw@ess.washington.edu
AF: Department of Earth and Space Sciences, 310 Condon Hall, University of Washington, Seattle, WA 98195 United States
AB: We have made side-by-side measurements in several boreholes at Summit, Greenland, using Borehole Optical Stratigraphy (BOS) and Neutron-Scattering density logging techniques. The BOS logs show a high degree of correlation at shallow depths with Neutron Scattering logs taken in the same borehole. This supports the hypothesis that BOS is detecting changes in both density and grain size, as well as possibly other parameters. The correlation between returned brightness and density decreases with depth and finally becomes negative, and we investigate the possible reasons for this inversion, which may be related to changes in densification regime from grain-boundary sliding to pressure sintering.
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 0915 Downhole methods
DE: 0994 Instruments and techniques
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting