Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-25T21:48:44.438Z Has data issue: false hasContentIssue false

Hydrodynamics in Holocene Lake Mega-Chad

Published online by Cambridge University Press:  20 January 2017

Frédéric Bouchette*
Affiliation:
GEOSCIENCES-M, Université Montpellier II et CNRS, cc 60, Place Eugène Bataillon, 34095 Montpellier cedex 5, France Institut de Mathématiques et modélisation de Montpellier, Université Montpellier II et CNRS, cc 51, Place Eugène Bataillon, 34095 Montpellier cedex 5, France
Mathieu Schuster
Affiliation:
Université de Poitiers UFR SFA, IPHEP - Institut International de Paléoprimatologie, Paléontologie Humaine: Evolution et Paléoenvironnements, CNRS UMR 6046, 40 avenue du Recteur Pineau, 86022 Poitiers, France
Jean-François Ghienne
Affiliation:
Institut de Physique du Globe de Strasbourg (CNRS/Université de Strasbourg, UMR 7516, EOST), 1, rue Blessig, 67084 Strasbourg, France
Cléa Denamiel
Affiliation:
HR-Wallingford, Howbery Park, Wallingford, OX10 8BA, UK
Claude Roquin
Affiliation:
Institut de Physique du Globe de Strasbourg (CNRS/Université de Strasbourg, UMR 7516, EOST), 1, rue Blessig, 67084 Strasbourg, France
Abderamane Moussa
Affiliation:
Université de Poitiers UFR SFA, IPHEP - Institut International de Paléoprimatologie, Paléontologie Humaine: Evolution et Paléoenvironnements, CNRS UMR 6046, 40 avenue du Recteur Pineau, 86022 Poitiers, France Institut de Physique du Globe de Strasbourg (CNRS/Université de Strasbourg, UMR 7516, EOST), 1, rue Blessig, 67084 Strasbourg, France
Patrick Marsaleix
Affiliation:
Laboratoire d'Aérologie-CNRS et Université de Toulouse, 14, Avenue Edouard Belin, 31400 Toulouse, France
Philippe Duringer
Affiliation:
Institut de Physique du Globe de Strasbourg (CNRS/Université de Strasbourg, UMR 7516, EOST), 1, rue Blessig, 67084 Strasbourg, France
*
*Corresponding author.E-mail addresses:[email protected] (F. Bouchette), [email protected] (M. Schuster).

Abstract

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.

Type
Original Articles
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Akima, H., (1970). A new method of interpolation and smooth curve fitting based on local procedures. J. ACM 17, 4, 589602.Google Scholar
Armitage, S.J., Drake, N.A., Stokes, S., El-Hawat, A., Salem, M.J., White, K., Turner, P., McLaren, S.J., (2007). Multiple phases of North African humidity recorded in lacustrine sediments from the Fazzan Basin, Libyan Sahara. Quaternary Geochronology 2, 181186.CrossRefGoogle Scholar
Blumberg, A. F, Mellor, G. L., (1987). A description of a three-dimensional coastal ocean circulation model. Three-Dimensional Coastal Models, Coastal and Estuarine Sciences. Ed. N.S. Heaps, American Geophysical Union Geophysical Monograph Board, 4, 116.Google Scholar
Bouffard, J., Vignudelli, S., Herrmann, M., Lyard, F., Marsaleix, P., Ménard, Y., Cipollini, P., (2008). Comparison of ocean dynamics with a regional circulation model and improved altimetry in the north-western Mediterranean. Terrestrial, Atmospheric and Oceanic Sciences 19, 119..Google Scholar
Bristow, C.S., Drake, N., Armitage, S., (2009). Deflation in the dustiest place on Earth: the Bodélé Depression, Chad. Geomorphology 105, 1-2, 5058.Google Scholar
Burke, K., (1976). The Chad Basin: an active intra-continental basin. Tectonophysics 36, 197206.Google Scholar
Capot-Rey, R., (1961). Borkou et Ounianga. Etude de géographie régionale. Mémoire de l'Institut de Recherches Sahariennes. 5, Alger, 182 p.Google Scholar
Conrad, G., Lappartient, J.-R., (1991). The appearance of Cardium fauna and foraminifers in the great lakes of the early quaternary period in the Algerian central Sahara desert. Journal of African Earth Sciences 12, 375382.Google Scholar
Damnati, B., (2000). Holocene lake record in the Northern Hemisphere of Africa. Journal of African Earth Sciences 31, 253262.Google Scholar
Denamiel, C., (2006). Three dimensional coupled modeling of swell- and wind/buoyancy-driven currents at the midshelf scale during storm events. Phd Thesis, University of Montpellier II, , 197 p.Google Scholar
deMenocal, P., Ortiz, J., Guilderson, T., Adkins, J., Sarnthein, M., Baker, L., Yarusinsky, M., (2000). Abrupt onset and termination of the African Humid Period: rapid climate responses to gradual insolation forcing. Quaternary Science Reviews 19, 347361.CrossRefGoogle Scholar
Drake, N., Bristow, Ch, (2006). Shorelines in the Sahara: geomorphological evidence for an enhanced Monsoon from palaeolake Megachad. The Holocene 16, 901911.Google Scholar
Durand, A., (1995). Quaternary sediments and climate in the Central Sahel. African Geoscience Review 2, 323614.Google Scholar
Duringer, Ph., Schuster, M., Genise, J.F., Brunet, M., Vignaud, P., (2007). New trace fossils of termites, nests and galleries, from the Chad Basin (upper Miocene and Pliocene). Palaeogeography, Palaeoclimatology, Palaeoecology 251, 323353.Google Scholar
Engelstaedter, S., Tegen, I., Washington, R., (2006). North African dust emissions and transport. Earth Science Reviews 79, 73100.CrossRefGoogle Scholar
Ergenzinger, P.J., (1978). Das Gebiet des Enneri Misky im Tibesti Gebirge, Republique du Tchad. Erlauterungen zu einer Geomorphologischen Karte 1:200000. Berliner Geographischer Abhandlungen. 23, 71.Google Scholar
Estournel, C., Zervakis, V., Marsaleix, P., Papadopoulos, A., Auclair, F., Perivoliotis, L., Tragou, E., (2005). Dense water formation and cascading in the Gulf of Thermaikos (North Aegean) from observations and modelling. Continental Shelf Research 25, 23662386..Google Scholar
Fredsoe, J, Deigaard, R., (1995). Mechanics of coastal sediment transport. Advanced series on ocean engineering, third ed. World Scientific Publishing, Singapore. 3, 370 p.Google Scholar
Gasse, F., (2000). Hydrological changes in the African tropics since the Last Glacial Maximum. Quaternary Science Reviews 19, 189211.Google Scholar
Ghienne, J.-F., Schuster, M., Bernard, A., Duringer, Ph., Brunet, M., (2002). The Holocene giant Lake Chad revealed by Digital Elevation Models. Quaternary International 87, 8185.Google Scholar
Ghoneim, E., El-Baz, F., (2007). DEM-optical-radar data integration for palaeohydrological mapping in the northern Darfur, Sudan: implication for groundwater exploration. International Journal of Remote Sensing. 28, 50015018.CrossRefGoogle Scholar
Guiraud, R., Maurin, J.C., (1992). Early Cretaceous rifts of Western and Central Africa: an overview. Tectonophysics 213, 153168.CrossRefGoogle Scholar
Gumnior, M., Preusser, F., (2007). Late Quaternary river development in the southwest Chad Basin: OSL dating of sediment from the Komadugu palaeofloodplain (northeast Nigeria). Journal of Quaternary Sciences 22, 709719.Google Scholar
Hartley, R.W., Allen, P.A., (1994). Interior cratonic basins of Africa: relation to continental break-up and role of mantle convection. Basin Research 6, 95113.Google Scholar
Hoelzmann, Ph., Keding, B., Berke, H., Kroepelin, S., Kruse, H.-J., (2001). Environmental change and archaeology: lake evolution and human occupation in the eastern Sahara during the Holocene. Palaeogeography, Palaeoclimatology, Palaeoecology 169, 193217.CrossRefGoogle Scholar
Leblanc, M., Leduc, C., Stagnitti, F., van Oevelen, P.J., Jones, C., Mofor, L.A., Razack, M., Favreau, G., (2006). Evidence for Megalake Chad, north-central Africa, during the late Quaternary from satellite data. Palaeogeography, Palaeoclimatology, Palaeoecology 230, 230242.Google Scholar
Lézine, A.-M., Duplessy, J.-Cl., Cazet, J.-P., (2005). West African Monsoon variability during the last deglaciation and the Holocene: evidence from fresh water algae, pollen and isotope data from core KW31, Gulf of Guinea. Palaeogeography, Palaeoclimatology, Palaeoecology. 219, 225237.Google Scholar
Krist Jr., F., Schaetzl, R.J., (2001). Palaeowind (11,000 BP) directions derived from lake spits in northern Michigan. Geomorphology 38, 118.Google Scholar
Kusnir, I., Moutaye, H.A., (1997). Ressources minérales du Tchad : une revue. Journal of African Earth Sciences 24, 549562.Google Scholar
Mainguet, M., Chemin, M.-C., (1990). Le Massif du Tibesti dans le systéme éolien du Sahara: reflexion sur la génèse du Lac Tchad. Berliner Geographische Studien 30, 261276.Google Scholar
Maley, J., (1977). Palaeoclimates of Central Sahara during the early Holocene. Nature 269, 573577.CrossRefGoogle Scholar
Maley, J., (1981). Etudes palynologiques dans le bassin du Tchad et Paléoclimatologie de l'Afrique nord tropicale de 30000 ans à l'époque actuelle, ed. ORSTOM, Paris. 129, 586 p.Google Scholar
Marsaleix, P., Auclair, F., Floor, J.W., Herrmann, M.J., Estournel, C., Pairaud, I., Ulses, C., (2008). Energy conservation issues in sigma-coordinate free-surface ocean models. Ocean Modelling 20, 6189..Google Scholar
Mellor, G., (2003). The three-dimensional current and surface wave equations. Journal of Physical Oceanography 33, 19781989.2.0.CO;2>CrossRefGoogle Scholar
Olivry, J.C., Chouret, A., Lemoalle, J., Bricquet, J.P., (1996). Hydrologie du lac Tchad. ORSTOM, Paris., 266.Google Scholar
Pachur, H.J., Rottinger, F., (1997). Evidence for large extended palaeolake in the eastern Sahara as revealed by spaceborne radar lab images. Remote Sensing of Environment 61, 437.CrossRefGoogle Scholar
Pachur, H.J., Hoelzmann, P., (2000). Late Quaternary palaeoecology and palaeoclimates of the eastern Sahara. Journal of African Earth Sciences 30, 929939.CrossRefGoogle Scholar
Petit-Maire, N., Casta, L., Delibrias, G., Gaven, Ch., Testud, A.-M., (1980). Preliminary Data on Quaternary Palaeolacustrine Deposits in the Wadi ash Shati Area, Libya. Salem, M.J., Busrewil, M.T., The Geology of Libya III. Academic Press, London, 797807.Google Scholar
Petit-Maire, N., Riser, J., (1983). Sahara ou Sahel? Quaternaire récent du Bassin de Taoudenni (Mali). CNRS, Marseille., 473.Google Scholar
Pias, J., Guichard, E., (1957). Origine et conséquences de l'existence d'un cordon sableux dans la partie sud-ouest de la cuvette tchadienne. Compte Rendu Académie des Sciences de Paris 244, 791793.Google Scholar
Rabus, B., Eineder, M., Roth, A., Bamler, A., (2003). The shuttle radar topography mission a new class of digital elevation models acquired by spaceborne radar. ISPRS Journal of Photogrammetry and Remote Sensing 57, 241262.Google Scholar
Shchepetkin, A.F., Mc Williams, J.C., (2005). The regional oceanic modeling system (roms): A split-explicit, free surface, topography-following-coordinate oceanic model. Ocean Modelling 9, 347404.Google Scholar
Schneider, J.L., (1967). Evolution du dernier lacustre et peuplement préhistorique aux Pays Bas du Tchad. Bulletin ASEQUA 14/15, 203215.Google Scholar
Schuster, M., (2002). Sédimentologie et paléoécologie des series vertébrés du paléolac Tchad depuis le Miocène supérieur. PhD thesis, University of Strasbourg, , 152 p.Google Scholar
Schuster, M., Duringer, Ph., Ghienne, J.-F., Bernard, A., Brunet, M., Vignaud, P., Mackaye, H.T., (2001). The Holocene Lake Mega-Chad: extension, dynamic and palaeoenvironmental implications since upper Miocene. European Union of Geosciences XI, Strasbourg, France, 8-12 April 2001. Abstract book and CDROM. 177.Google Scholar
Schuster, M., Duringer, Ph., Ghienne, J.-F., Vignaud, P., Beauvilain, A., Mackaye, H.T., Brunet, M., (2003). Coastal conglomerate around the Hadjer el Khamis inselbergs (western Chad, Central Africa): new evidence for Lake Mega-Chad episodes. Earth Surface Processes and Landforms 28, 10591069.Google Scholar
Schuster, M., Roquin, C., Brunet, M., Duringer, Ph., Fontugne, M., Mackaye, H.T., Vignaud, P., Ghienne, J.-F., (2005). Highlighting Holocene Lake Mega-Chad paleoshorelines from space. Quaternary Science Reviews 24, 18211827.CrossRefGoogle Scholar
Sepulchre, P., Schuster, M., Ramstein, G., Krinner, G., Girard, J.-F., Fluteau, F., Vignaud, P., Brunet, M., (2008). Simulating the Holocene Lake Mega Chad with an AGCM coupled with a lake model: a preliminary approach. Global and Planetary Change 61, 4148.CrossRefGoogle Scholar
Servant, M., Servant-Vildary, S., (1980). L'environnement Quaternaire du Bassin du Tchad. Williams, M.A.J., Faure, H., The Sahara and the Nile. Balkema, Rotterdam., 133162.Google Scholar
Short, A.D., (1999). Handbook of beach shoreface and morphodynamics. Wiley and Sons, 380.Google Scholar
Ulses, C., Grenz, C., Marsaleix, P., Schaaff, E., Estournel, C., Meulé, S., Pinazo, C., (2005). Circulation in a semi enclosed bay under the influence of strong fresh water input. Journal of Marine Systems 56, 113132..Google Scholar
Ulses, C., Estournel, C., Puig, P., Durrieu de Madron, X., Marsaleix, P., (2008). Dense shelf water cascading in the north-western Mediterranean during the cold winter 2005. Quantification of the export through the Gulf of Lion and the Catalan margin. Geophysical Research Letters 35, L07610 .Google Scholar
Vignaud, P., Duringer, Ph., Mackaye, H.T., Likius, A., Blondel, C., Boisserie, J.-R., de Bonis, L., Eisenmann, V., Etienne, M., Geraads, D., Guy, F., Lehmann, Th., Lihoreau, F., Lopez-Martinez, N., Mourer-Chauviré, C., Otero, O., Rage, J.-Cl., Schuster, M., Viriot, L., Zazzo, A., Brunet, M., (2002). Geology and palaeontology of the Upper Miocene Toros-Menalla hominid locality, Chad. Nature 418, 152155.CrossRefGoogle ScholarPubMed
Warren, A, Chappell, A, Todd, M. C, Bristow, C, Drake, N, Engelstaedter, S, Martins, V, M'bainayel, S, Washington, R., (2007). Dust-raising in the dustiest place on earth. Geomorphology 92, 1–2, 2537.Google Scholar
Wessel, P., Smith, W.H.F., (1998). New, improved version of the Generic Mapping Tools Released. EOS Trans, ed. American Geophysical Union 79, 579.Google Scholar
Wolf, J. P., (1964). Carte géologique de la République du Tchad au 1/15000000ème, ed. BRGM, Paris.Google Scholar