DOI: 10.1016/j.palaeo.2016.06.038
论文题名: Deep water circulation within the eastern Mediterranean Sea over the last 95 kyr: New insights from stable isotopes and benthic foraminiferal assemblages
作者: Cornuault M. ; Vidal L. ; Tachikawa K. ; Licari L. ; Rouaud G. ; Sonzogni C. ; Revel M.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 459 起始页码: 1
结束页码: 14
语种: 英语
英文关键词: Benthic foraminifera
; Mediterranean Sea
; North Atlantic variability
; Oxygenation
; Sapropels
; Ventilation
英文摘要: The response of eastern Mediterranean Sea (EMS) circulation to climate forcings over the last 95 kyr BP was studied using core MD04-2722, collected at 1780 m water depth within the Levantine Sea. Foraminiferal stable isotopes and benthic assemblages were combined in order to reconstruct deep water ventilation and oxygenation in relation to surface water freshening. Over the last deglaciation, benthic foraminiferal δ13C values and oxygen index decreased, while the δ18O gradient between benthic and planktonic foraminifera increased. The results, respectively, indicate slower ventilation, bottom water oxygen depletion, and stronger stratification prior to S1 sapropel deposition. A combination of deglacial sea level rise and fresher north Atlantic surface water contributions were determined to be a precondition for S1 formation within the Levantine Sea. Local Nile River freshwater supplied during the African Humid Period further strengthened water column stratification. As for S3 deposit, the central role of monsoonal precipitation was estimated. For the last glacial period, three events at around 53, 46 and 37 ka BP were marked by a deep water circulation reduction at the core location. Considering the influence of north Atlantic surface water salinity on Mediterranean Sea circulation, we propose that the 46 and 37 ka BP events are responses to Heinrich Events 4 and 5 that supplied fresher surface water to the Mediterranean Sea. Since the ‘53 ka event’ was also characterized by the appearance of low oxygen benthic indicators as observed within the S1 and S3 layers, we tentatively attributed it to ‘missing’ sapropel S2. Our results indicate that intense stagnation within the EMS could occur when both the local freshwater supply and fresher north Atlantic surface water are contributors. The influence of north Atlantic conditions was significant to EMS circulation under warm and cold climate conditions. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68304
Appears in Collections: 过去全球变化的重建
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作者单位: Aix-Marseille Université, CNRS, IRD, CEREGE UM34, Aix-en-Provence, France; GEOPS UMR 8148 CNRS, Université Paris Sud, Bâtiment 504, Orsay, France; Geoazur, UMR 7329, Valbonne-Sophia Antipolis, France
Recommended Citation:
Cornuault M.,Vidal L.,Tachikawa K.,et al. Deep water circulation within the eastern Mediterranean Sea over the last 95 kyr: New insights from stable isotopes and benthic foraminiferal assemblages[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,459