ITCZ and ENSO-like pacing of Nile delta hydro-geomorphology during the Holocene

Marriner, Nick; Flaux, Clément; Kaniewski, David; Morhange, Christophe; Leduc, Guillaume; Moron, Vincent; Chen, Zhongyuan; Gasse, Françoise; Empereur, Jean‐Yves; Stanley, Jean‐Daniel

doi:10.1016/j.quascirev.2012.04.022

Cited by 100 publications

(58 citation statements)

References 62 publications

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“…Additionally, the southward retreat of ITCZ and a shortening in summer monsoonal periods have been reported from speleothem in Qunf cave (Southern Omman) to have occurred after 7.5 cal ka BP (Fig. 6a) in response to reduced solar activity [Fleitmann et al, 2003[Fleitmann et al, , 2007Marriner et al, 2012]. This conforms with the reconstruction of Nile hydrological activity [Weldeab et al, 2014] and the southward migration of vegetation [H ely et al, 2014].…”

Section: The 74 Cal Ka Bp Eventsupporting

confidence: 83%

Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

Filippidi

Triantaphyllou

Lange

2016

Quaternary Science Reviews

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a b s t r a c tPresent-day bottom-water ventilation in the Eastern Mediterranean basin occurs through deep-water convection originating from the two marginal basins, i.e. Adriatic and Aegean Seas. In the paleo record, long periods of enhanced deep-water formation have been alternating with shorter periods of reduced deep-water formation. The latter is related mainly to low-latitude humid climate conditions and the enhanced deposition and preservation of organic-rich sediment units (sapropels). This study focuses on sedimentary archives of the most-recent sapropel S1, retrieved from two sites under the direct influence of the two deep-water formation areas. Restricted oxygen conditions have developed rapidly at the beginning of S1 deposition in the Adriatic site, but bottom-water conditions have not persistently remained anoxic during the full interval of sapropel deposition. In fact, the variability in intensity and persistence of sedimentary redox conditions at the two deep-water formation sites is shown to be related to brief episodes of climate cooling. In the Adriatic site, sapropel deposition appears to have been interrupted twice. The 8.2 ka event, only recovered at the Adria site, is characterized by gradually increasing suboxic to possibly intermittently oxic conditions and decreasing C org fluxes, followed by an abrupt re-establishment of anoxic conditions. Another important event that disrupted sapropel S1 formation, has taken place at ca. 7.4 cal ka BP. The latter event has been recovered at both sites. In the Adriatic site it is followed by a period of sedimentary conditions that gradually change from suboxic to more permanently oxic, as deduced from the Mn/Al pattern. Using the same proxy for suboxic/oxic sedimentary redox conditions, we observe that conditions in the Aegean Sea site shift to more permanently oxic from the 7.4 ka event onwards. However, at both sites the accumulation and preservation of enhanced amounts of organic matter have continued under these suboxic to intermittently oxic sedimentary conditions. It seems thus, that after 7.4 cal ka BP sapropel-like surface or deep-chlorophyllmaximum conditions including enhanced productivity continued, whereas bottom-water conditions were at least intermittently oxic. The latter is related to decreasing precipitation, i.e. run-off, and thus a progressive development and deepening of deep-water formation. The shallower Aegean site, would be affected earlier by such deepening ventilation than the slightly deeper Adriatic site. Finally, termination of sapropel S1 formation as deduced from diminished organic matter contents and Ba/Al, appears to have occurred almost simultaneously in the two areas, namely at 6.6 ± 0.3 and 6.3 ± 0.5 cal ka BP in Adriatic and Aegean sites, respectively.

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Section: The 74 Cal Ka Bp Eventsupporting

confidence: 83%

Eastern-Mediterranean ventilation variability during sapropel S1 formation, evaluated at two sites influenced by deep-water formation from Adriatic and Aegean Seas

Filippidi

Triantaphyllou

Lange

2016

Quaternary Science Reviews

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“…Moreover, recent investigations in the Nile delta and at several eastern African lakes (Wolff et al 2011;Marriner et al 2012) suggested that, beside the fundamental contribution of the monsoon systems, Northeastern Africa and the Nile river catchment were also sensitive to El Niño Southern Oscillation (ENSO); the effects of ENSO have varied at a sub-millennial timescale during the Holocene.…”

Section: Climatic Backgroundmentioning

confidence: 99%

Holocene Supra-Regional Environmental Changes as Trigger for Major Socio-Cultural Processes in Northeastern Africa and the Sahara

Gatto

Zerboni

2015

Afr Archaeol Rev

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This contribution presents the environmental changes that occurred over the last ten millennia in a vast region of North Africa, encompassing the Central Sahara, the Greater Nile Valley and the Horn of Africa. These areas are of particular significance in the continent because of the early socioeconomic transformations that occurred there. An up-to-date review of palaeoclimate research is proposed with the aim to highlight new theoretical approaches, analytical methods and innovative techniques. Results of recent research on high-resolution and well-dated palaeoenvironmental archives for proxy data have been used to understand the climatic variability at different scales of resolution. We trace the regional changes in Holocene palaeohydrology, mostly regulated by monsoonal precipitation, and their effects on the landscape, and highlight the occurrence of short-term climatic events, arid or humid that may have had disruptive consequences on human communities. The contribution also discusses the cultural dynamics that occurred in those regions because the latter were exploited by hunter/ gatherer groups from the onset of the Holocene until historical times. A reconstruction of patterns of human adjustment to climatic variability is here presented, focusing on key processes such as the origin of food production, social complexity and power, and the rise and fall of complex polities and interregional networks.Résumé Cette contribution présente les changements environnementaux survenus au cours des dix derniers millénaires dans une vaste région de l'Afrique du Nord, englobant le Sahara Central, la vallée du Nile, et la Corne de l'Afrique. Ces zones sont Afr Archaeol Rev (2015) 32:301-333 d'une importance particulière, car ce sont là que les processus de développement socio-économiques se sont initialement produits sur le continent. Une revue à jour de la recherche paléoclimatique est proposée dans le but de mettre en évidence de nouvelles approches théoriques, méthodes analytiques et techniques innovantes. Les résultats de recherches récentes sur des archives paléoenvironnementales à haute résolution et bien datées ont été utilisées pour comprendre la variabilité climatique à différentes échelles, traçant les changements régionaux dans la paléohydrologie de l'Holocène, principalement régis par les précipitations de mousson, et leurs effets sur le paysage et soulignant l'apparition de courts événements climatiques, aride ou humide, qui ont pu avoir des conséquences perturbatrices sur les communautés humaines. Cette contribution aborde également les dynamiques culturelles qui ont eu lieu dans ces régions depuis qu'elles ont été exploitées par des groupes de chasseurs/cueilleurs du début de l'Holocène aux périodes historiques. Une reconstruction des schémas d'adaptation humaine aux variations climatiques est présentée ici, en se concentrant sur des processus clés, tels que l'origine de la production alimentaire, la complexité sociale et le pouvoir; ainsi que sur l'essor et la chute de systèmes politiques complexes et de ...

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“…years BP to present. The y-axis is probability per year and the x-axis corresponds to the calibrated radiocarbon years BP (Marriner et al, 2012); (H) Laguna Pallcacocha, southern Ecuador ENSO record (Moy et al, 2002) showing the number of ENSO events per 100 years; (I) river flow at the Nile delta (Bernhardt et al, 2012); and (J) Time variations of elemental content in Nile deep-sea fan Holocene sediments (Blanchet et al, 2013). Ti/Ca ratio is a tracer for marine versus terrigenous sedimentation.…”

Section: Selected Studiesmentioning

confidence: 99%

“…These include a 256 year cycle, additional periodicities of 64, 19, 12 and 7 years and, most striking, quasi-quadrennial (4.2 year) and quasi-biennial modes (2.2 year) that support the long established connection between Nile River discharge and ENSO in the Indo-Pacific ocean. The cold e La Niña e phase of ENSO is associated with a more intense Ethiopian Monsoon and increased erosion and flow from the Blue Nile catchment, and El Niño years are characterised by periods of reduced flow and drought (Marriner et al, 2012). The longest periods may be of astronomical/solar origin but the 7 year cycle seems to be due to Atlantic influences, and possibly may be the origin cycle of runs of 'lean' and 'fat' years as mentioned in the biblical story of Joseph.…”

Section: Nile Catchment and Hydrologymentioning

confidence: 99%

“…Clear archaeological benefits from using such approaches have been demonstrated for some time in the American Southwest, where investigations have been coupled with processbased analysis of dynamic fluvial environments, underpinned by robust geochronologies (Waters and Field, 1986;Huckleberry, 1995;Waters, 2000;Clevis et al, 2006;Huckleberry et al, 2013). Similar geomorphological advances are now being made in the Nubian Williams et al, 2010;Macklin et al, 2013b) and Egyptian Nile (Bunbury et al, 2008;Ghilardi and Boraik, 2011;Marriner et al, 2012;Butzer et al, 2013), in the Indus valley (Giosan et al, 2012), and in the Huang He (Yellow River) region of China (Kidder et al, 2012).…”

Section: Introductionmentioning

confidence: 96%

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