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Laboratoire d'aérologie |  |
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Laboratoire d'aérologie | |
| HAL : hal-00475633, version 1 |
| DOI : 10.1016/j.yqres.2009.10.010 |
| Fiche détaillée |  Récupérer au format |
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| Quaternary Research 73, 2 (2010) 226-236 |
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| Hydrodynamics in Holocene Lake Mega-Chad |
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Frederic Bouchette 1Mathieu Schuster 2 |
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| (2010) |
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| Holocene Lake Mega-Chad (LMC) was the largest late Quaternary water-body in Africa. The development of this giant paleo-lake is related to a northward shift of the isohyetes interpreted as evidence for an enhanced Monsoon (African Humid Period). Numerous preserved coastal features have been described all around the LMC shore. Such features reveal the main paleo-hydrodynamical tendencies. In the context of a closed water-body like LMC, hydrodynamics are forced mainly by winds. We use a three-dimensional numerical model (SYMPHONIE) to simulate the mean hydrodynamics in LMC under both Harmattan-like (northeasterly trade winds) and Monsoon-like (southwesterly winds) forcings. The northern part of LMC displays coastal features, such as sand spits, that are consistent with the simulations forced by Harmattan-like winds. Geomorphic features related to Monsoon-driven hydrodynamics are not clearly expressed. They could have developed during the early stage of LMC but subsequently reworked. At the time of sand-spit building, Harmattan-like driven hydrodynamics prevailed and related coastal features were preferentially preserved in the sedimentary record. |
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| 1 : | Géosciences Montpellier (GM) |
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CNRS : UMR5243 – Université Montpellier II - Sciences et techniques |
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| 2 : | Institut International de Paléoprimatologie, Paléontologie Humaine : Evolution et Paléoenvironnement (IPHEP) |
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CNRS : UMR6046 – Université de Poitiers |
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| 3 : | Institut de physique du globe de Strasbourg (IPGS) |
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CNRS : UMR7516 – INSU – Université de Strasbourg |
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| 4 : | HR-Wallingford, |
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inconnue |
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| 5 : | Laboratoire d'aérologie (LA) |
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CNRS : UMR5560 – Observatoire Midi-Pyrénées – INSU – Université Paul Sabatier [UPS] - Toulouse III |
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| Domaine | : | Planète et Univers/Interfaces continentales, environnement Sciences de l'environnement/Milieux et Changements globaux |
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| Wind-driven circulation – Sand spits – Wave-cut terrace – Monsoon – Trade winds – SYMPHONIE – Coastal modelling – Paleo-lake – Africa – Sahara – Alongshore drift |
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| hal-00475633, version 1 | |
| http://hal.archives-ouvertes.fr/hal-00475633 | |
| oai:hal.archives-ouvertes.fr:hal-00475633 | |
| Contributeur : Gm Aigle | |
| Déposé pour le compte de : | |
| Soumis le : Jeudi 22 Avril 2010, 14:37:33 | |
| Dernière modification le : Jeudi 22 Avril 2010, 14:37:34 | |
