Ice-flow characteristics over a rough bedrock: Implications for ice-core interpretation.
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Accession number;03A0155374
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| Title;Ice-flow characteristics over a rough bedrock: Implications for ice-core interpretation. |
| Author;
PATTYN F
(Vrije Univ. Brussel, Brussel, Bel)
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Journal Title;Polar Meteorol Glaciol (Nat Inst Polar Res)
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Journal Code:X0871A
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ISSN:1344-3437
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VOL.;NO.16;PAGE.42-52(2002)
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| Figure&Table&Reference;FIG.7, REF.19 |
| Pub. Country;Japan |
| Language;English |
| Abstract;Recent observations in western Dronning Maud Land, Antarctica, point to a relatively high bedrock roughness in the area of the future EPICA drilling site. It is commonly accepted that such a roughness does not favor the interpretation of deep ice cores as basal ice-sheet interactions might disturb the bottom ice layers. The present study aims at examining the ice-flow characteristics over a strongly undulating bed and investigates its influence on age-depth profiles in the ice sheet. For this purpose a high-resolution time-dependent two-dimensional flowline model was developed(horizontal gridsize.LEQ.1km), taking into accound all relevant stresses at such a small scale. The model is solved on a fixed finite-difference grid, and compared with a similar model, solving the velocity field according to the shallow-ice approximation. The analysis is presented for sinusoidal bedrock undulations with amplitude-to-wavelength ratio comparable to those observed by radio-echo sounding(D. Steinhage et al., Ann. Glaciol., 29, 267, 1999). Calculations are performed over a period of 300ka. Results demonstrate that the influence of a high bed roughness on the age-depth profiles is not only confined close to the bed, but near the surface as well, which might affect the interpretation of shallow ice cores. (author abst.) |
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