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| Titel |
Where to find 1.5 million yr old ice for the IPICS "Oldest-Ice" ice core |
| VerfasserIn |
H. Fischer, J. Severinghaus, E. Brook, E. Wolff, M. Albert, O. Alemany, R. Arthern, C. Bentley, D. Blankenship, J. Chappellaz, T. Creyts, D. Dahl-Jensen, M. Dinn, M. Frezzotti, S. Fujita, H. Gallée, R. Hindmarsh, D. Hudspeth, G. Jugie, K. Kawamura, V. Lipenkov, Heinrich Miller  , R. Mulvaney, F. Parrenin, F. Pattyn, C. Ritz, J. Schwander, D. Steinhage, T. Ommen, F. Wilhelms |
| 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. 6 ; Nr. 9, no. 6 (2013-11-05), S.2489-2505 |
| Datensatznummer |
250085256
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| Publikation (Nr.) |
 copernicus.org/cp-9-2489-2013.pdf |
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| Zusammenfassung |
| The recovery of a 1.5 million yr long ice core from Antarctica represents a
keystone of our understanding of Quaternary climate, the progression of
glaciation over this time period and the role of greenhouse gas cycles in
this progression. Here we tackle the question of where such ice may still be
found in the Antarctic ice sheet. We can show that such old ice is most
likely to exist in the plateau area of the East Antarctic ice sheet (EAIS)
without stratigraphic disturbance and should be able to be recovered after
careful pre-site selection studies. Based on a simple ice and heat flow model
and glaciological observations, we conclude that positions in the vicinity of
major domes and saddle position on the East Antarctic Plateau will
most likely have such old ice in store and represent the best study areas for
dedicated reconnaissance studies in the near future. In contrast to previous
ice core drill site selections, however, we strongly suggest significantly
reduced ice thickness to avoid bottom melting. For example for the geothermal
heat flux and accumulation conditions at Dome C, an ice thickness lower than
but close to about 2500 m would be required to find 1.5 Myr
old ice (i.e., more than 700 m less than at the current EPICA Dome C drill
site). Within this constraint, the resolution of an Oldest-Ice record and the
distance of such old ice to the bedrock should be maximized to avoid ice
flow disturbances, for example, by finding locations with minimum geothermal
heat flux. As the geothermal heat flux is largely unknown for the EAIS, this
parameter has to be carefully determined beforehand. In addition, detailed
bedrock topography and ice flow history has to be reconstructed for
candidates of an Oldest-Ice ice coring site. Finally, we argue strongly for
rapid access drilling before any full, deep ice coring activity commences to
bring datable samples to the surface and to allow an age check of the oldest
ice. |
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