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https://hdl.handle.net/11681/5916
Title: | Criteria for measurement of strain rates in deep bore holes in polar glaciers |
Authors: | University of Miami. Bader, Henri, 1907- |
Keywords: | Glaciers Drilling Coring Bore holes Polar regions Flow measurements Measurements Strains Strain rates Models Mathematical models Stresses Ice Ice sheets Ice caps EPOLAR |
Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | Research report (Cold Regions Research and Engineering Laboratory (U.S.)) ; 127. |
Description: | Research Report Summary: The problem of strain rate measurement in bore holes is analyzed and the necessary accuracy is estimated. Based on a simplified model, strain rates are calculated as a function of depth below the surface for Camp Century, Greenland, and Byrd Station, Antarctica. It is assumed that (1) there are no strains normal to the vertical plain containing the flow lines, and (2) the thickness above any fixed point on the bed is constant. The drill hole is in the accumulation area. The components of the vertical strain rate are : (1) layer thinning to compensate for accumulation, (2) layer thinning or thickening when surface and bed slopes are unequal, (3) layer thinning by reduction of enclosed air volume, and (4) layer thinning due to elastic compression of ice. Inclinometer measurements can only be expected to yield the horizontal shear strain rate. An expression is given for correcting the non-verticality of the drill hole. The results indicate that only very high measurement accuracy is likely to yield useful results. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/5916 |
Appears in Collections: | Research Report |
Files in This Item:
File | Description | Size | Format | |
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CRREL-Research-Report-127.pdf | 647.28 kB | Adobe PDF | ![]() View/Open |