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| Titel |
Using ice-flow models to evaluate potential sites of million year-old ice in Antarctica |
| VerfasserIn |
B. Liefferinge, F. Pattyn |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 9, no. 5 ; Nr. 9, no. 5 (2013-10-18), S.2335-2345 |
| Datensatznummer |
250085233
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| Publikation (Nr.) |
 copernicus.org/cp-9-2335-2013.pdf |
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| Zusammenfassung |
| Finding suitable potential sites for an undisturbed record of million-year
old ice in Antarctica requires slow-moving ice (preferably an ice divide) and
basal conditions that are not disturbed by large topographic variations.
Furthermore, ice should be thick and cold basal conditions should prevail,
since basal melting would destroy the bottom layers. However, thick ice
(needed to resolve the signal at sufficient high resolution) increases basal
temperatures, which is a conflicting condition for finding a suitable drill
site. In addition, slow moving areas in the center of ice sheets are also
low-accumulation areas, and low accumulation reduces potential cooling of the
ice through vertical advection. While boundary conditions such as ice
thickness and accumulation rates are relatively well constrained, the major
uncertainty in determining basal thermal conditions resides in the geothermal
heat flow (GHF) underneath the ice sheet. We explore uncertainties in
existing GHF data sets and their effect on basal temperatures of the Antarctic
Ice Sheet, and propose an updated method based on Pattyn (2010) to improve
existing GHF data sets in agreement with known basal temperatures and their
gradients to reduce this uncertainty. Both complementary methods lead to a
better comprehension of basal temperature sensitivity and a characterization
of potential ice coring sites within these uncertainties. The combination of
both modeling approaches show that the most likely oldest ice sites are
situated near the divide areas (close to existing deep drilling sites, but in
areas of smaller ice thickness) and across the Gamburtsev Subglacial
Mountains. |
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