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| HAL : insu-00647437, version 1 |
| DOI : 10.3189/002214311798043690 |
| Fiche détaillée |  Récupérer au format |
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| Journal of Glaciology 57, 205 (2011) 942-948 |
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| Competition between grain growth and grain-size reduction in polar ice |
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| J. Roessiger 1P. D. Bons 1 |
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| (01/10/2011) |
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| Static (or 'normal') grain growth, i.e. grain boundary migration driven solely by grain boundary energy, is considered to be an important process in polar ice. Many ice-core studies report a continual increase in average grain size with depth in the upper hundreds of metres of ice sheets, while at deeper levels grain size appears to reach a steady state as a consequence of a balance between grain growth and grain-size reduction by dynamic recrystallization. The growth factor k in the normal grain growth law is important for any process where grain growth plays a role, and it is normally assumed to be a temperature-dependent material property. Here we show, using numerical simulations with the program Elle, that the factor k also incorporates the effect of the microstructure on grain growth. For example, a change in grain-size distribution from normal to log-normal in a thin section is found to correspond to an increase in k by a factor of 3.5. |
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| 1 : | Institut fur Geowissenschaften |
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Eberhard Karls Universität |
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| 2 : | Departament de Geologia |
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Universitat Autónoma de Barcelona |
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| 3 : | Laboratoire des Mécanismes et Transfert en Géologie (LMTG) |
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CNRS : UMR5563 – Observatoire Midi-Pyrénées – Université Paul Sabatier [UPS] - Toulouse III – Institut de recherche pour le développement [IRD] : UMR154 |
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| 4 : | Australian Crustal Research Centre, School of Geosciences, Monash University |
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Monash University |
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| 5 : | Laboratoire de glaciologie et géophysique de l'environnement (LGGE) |
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CNRS : UMR5183 – OSUG – INSU – Université Joseph Fourier - Grenoble I |
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| 6 : | Alfred-Wegener-Institut für Polar- und Meeresforschung |
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Alfred-Wegener-Institut für Polar- und Meeresforschung |
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| 7 : | Universität Göttingen (GZG) |
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Universität Göttingen - Geowissenschaftliches Zentrum der Universität Göttingen |
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| EDGE |
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| domaine | : | Planète et Univers/Sciences de la Terre/Géomorphologie |
| insu-00647437, version 1 | |
| http://hal-insu.archives-ouvertes.fr/insu-00647437 | |
| oai:hal-insu.archives-ouvertes.fr:insu-00647437 | |
| Contributeur : Pascale Talour | |
| Soumis le : Vendredi 2 Décembre 2011, 09:34:48 | |
| Dernière modification le : Lundi 20 Février 2012, 14:12:15 | |
