Impact of iceberg melting on Mediterranean thermohaline circulation during Heinrich events

Sierro, Francisco J.; Hodell, David A; Curtis, Jason H.; Flores, José Abel; Reguera, María Isabel; Colmenero-Hidalgo, Elena; Bárcena, María Ángeles; Grimalt, Joan O.; Cacho, Isabel; Frigola, Jaime; Canals, Miquel

doi:10.1029/2004pa001051

Cited by 205 publications

(258 citation statements)

References 64 publications

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“…For core RHS-KS-33, we correlated the quantitative calcium profile with the calcium carbonate content of twin core MD99-2348 (Fig. S1a and S1b) (Sierro et al, 2009). Age model of core MD99-2348 is based on 13 calibrated AMS 14 C dates for the last 21 ka (Sierro et al, 2009).…”

Section: Age Modelmentioning

confidence: 99%

“…S1a and S1b) (Sierro et al, 2009). Age model of core MD99-2348 is based on 13 calibrated AMS 14 C dates for the last 21 ka (Sierro et al, 2009). For core KESC9-30, we correlated scanner calcium profiles with the same data of reference core KNI23 ( Fig.…”

Section: Age Modelmentioning

confidence: 99%

“…The Mediterranean Sea is a small size basin, particularly sensitive to climatic variations and references therein). Particularly, continental margins of the Western Mediterranean Sea offer an exceptional preservation of recent climatic changes with high sedimentation rates because of the youth of this small Liguro-Provençal ocean Sierro et al, 2009). In this region, the subseafloor microbial community composition, diversity and distribution are barely documented, contrary to microbial communities from the water column (Danovaro et al, 2010), surficial sediments (Polymenakou et al, 2005b;Polymenakou et al, 2009), brines (La Cono et al, 2011) or mud volcanoes (Lazar et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

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Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

et al. 2012

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Abstract. An interdisciplinary study was conducted to evaluate the relationship between geological and paleoenvironmental parameters and the bacterial and archaeal community structure of two contrasting subseafloor sites in the Western Mediterranean Sea (Ligurian Sea and Gulf of Lion). Both depositional environments in this area are well-documented from paleoclimatic and paleooceanographic point of views. Available data sets allowed us to calibrate the investigated cores with reference and dated cores previously collected in the same area, and notably correlated to Quaternary climate variations. DNA-based fingerprints showed that the archaeal diversity was composed by one group, Miscellaneous Crenarchaeotic Group (MCG), within the Gulf of Lion sediments and of nine different lineages (dominated by MCG, South African Gold Mine Euryarchaeotal Group (SAGMEG) and Halobacteria) within the Ligurian Sea sediments. Bacterial molecular diversity at both sites revealed mostly the presence of the classes Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria within Proteobacteria phylum, and also members of Bacteroidetes phylum. The second most abundant lineages were Actinobacteria and Firmicutes at the Gulf of Lion site and Chloroflexi at the Ligurian Sea site. Various substrates and cultivation conditions allowed us to isolate 75 strains belonging to four lineages: Alpha-, Gammaproteobacteria, Firmicutes and Actinobacteria. In molecular surveys, the Betaproteobacteria group was consistently detected in the Ligurian Sea sediments, characterized by a heterolithic facies with numerous turbidites from a deep-sea levee. Analysis of relative betaproteobacterial abundances and turbidite frequency suggested that the microbial diversity was a result of main climatic changes occurring during the last 20 ka. Statistical direct multivariate canonical correspondence analyses (CCA) showed that the availability of electron acceptors and the quality of electron donors (indicated by age) strongly influenced the community structure. In contrast, within the Gulf of Lion core, characterized by a homogeneous lithological structure of upper-slope environment, most detected groups were Bacteroidetes and, to a lesser extent, Betaproteobacteria. At both site, the detection of Betaproteobacteria coincided with increased terrestrial Published by Copernicus Publications on behalf of the European Geosciences Union. 3492M.-C. Ciobanu et al.: Sedimentological imprint on subseafloor microbial communities inputs, as confirmed by the geochemical measurements (Si, Sr, Ti and Ca). In the Gulf of Lion, geochemical parameters were also found to drive microbial community composition. Taken together, our data suggest that the palaeoenvironmental history of erosion and deposition recorded in the Western Mediterranean Sea sediments has left its imprint on the sedimentological context for microbial habitability, and then indirectly on structure and composition of the microbial communities during the late Quaternary.

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Section: Age Modelmentioning

confidence: 99%

Section: Age Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

et al. 2012

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“…In fact, the lower global sea level during the last glacial may have led to a strong decrease in the Atlantic/Mediterranean exchange and a subsequent density gradient increase between surface and subsurface water [63,64], significantly suppressing vertical mixing. The same effect may be ascribed to the inflow of fresher water of polar origin during Stadials that is documented by light oxygen isotopic values in planktonic foraminifera shells in coincidence of most of North Atlantic Heinrich events [16,65]. Both these processes are suitable to explain the disturb in surface productivity in Stadials of the upper part of MIS 5 in the Sicily Channel record, given that the S 25 event marks the first significant sea level drop [66,67] and the first significant occurrence of ice rafted detritus in the North Atlantic record [68] since the MIS 6/MIS 5 transition.…”

Section: Paleoproductivity Variationsmentioning

confidence: 76%

Ten Years of Paleoceanographic Studies at ODP Site 963 (Central Mediterranean Sea)

Stefano

Incarbona

Sprovieri³

et al. 2014

TOPALOJ

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Abstract:The geographical location, the shape and the circulation pattern makes the Mediterranean Sea an ideal laboratory to study the interplay between different climatic systems, abrupt climate changes and the response of marine ecosystems. The Ocean Drilling Program Site 963 was drilled in the Northwestern part of the Sicily Channel, the sill that divides the western from the eastern Mediterranean Sea. Numerous papers have been published on Site 963 sediments in the last decade, investigating Mediterranean paleoceanographic themes. Here we offer a synthetic framework of these investigations carried out by sub-centennial resolution. We present the whole sequence of suborbital climatic oscillations over the last 130 kyr, that is since the last interglacial period, and we claim that teleconnection with Greenland and North Atlantic regions is the most likely phenomenon to explain our results. Furthermore we show the high sensitivity of marine planktonic (planktonic foraminifera and coccolithophores) ecosystems to Stadial/Interstadial fluctuations. We conclude that a three-steps scenario may describe productivity variations during each high-frequency oscillation, from Interstadial 24 to the last deglaciation (from 110 to 15 kiloyears ago): surface oligotrophy and a deep nutricline in the lower part of Interstadials; increased productivity, through a deep chlorophyll maximum and winter/spring coccolithophore blooms, during the upper part of Interstadials; a shallow nutricline during Stadials and possibly reduced productivity levels with respect to the upper Interstadial phase. Results from Site 963 investigations provide key information for very highresolution paleoceanographic research in the Mediterranean Sea.

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“…Green, black and red curves indicate confidence levels at respectively 95, 90 and 85%. (Rohling et al, 1998;Cacho et al, 1999;Pérez-Folgado et al, 2003;Sierro et al, 2005), and interpreted as the entrance of this species into the Mediterranean Sea during the southward shift of the Polar Front in the North Atlantic during the slow-down of North Atlantic Deep Water (NADW) formation. We argue that the lower abundance of N. pachyderma sx in both the eastern and the western Mediterranean Sea after the MPT is paradoxical, since colder conditions and a much thicker ice accumulation in Greenland and Antarctica sheets are documented (Lisiecki and Raymo, 2005).…”

Section: The Distribution Of N Pachyderma Sxmentioning

confidence: 99%

Orbital variations in planktonic foraminifera assemblages from the Ionian Sea during the Middle Pleistocene Transition

Incarbona

Dinarès-Turell

Stefano

et al. 2013

Palaeogeography, Palaeoclimatology, Palaeoecology

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The Middle Pleistocene Transition (1.2-0.7 Ma) is the most recent re-organization of the global climate system which includes variations in the frequency and amplitude of glacial/interglacial cycles, increased ice sheet volume, sea surface temperature cooling and a significant drop in the CO 2 atmospheric levels. Here we present high-resolution planktonic foraminifera data (mean sampling resolution of about 780 years) from core LC10 recovered in the Ionian Sea (eastern Mediterranean), between 1.2 and 0.9 Ma. Selected taxa, among them G. ruber, T. quinqueloba and G. bulloides, show significant periodicities that can be associated to orbital cycles, mainly precession and obliquity. The planktonic foraminifera based paleoclimatic curve exhibits a cooling linear trend that can be associated to similar phenomena observed in the North Atlantic. On the other hand, we refer to the influence of the North African Monsoon the occurrence of two peaks of the low-salinity tolerant species G. quadrilobatus that fall in coincidence of sapropel layers. Finally, we discuss the distribution pattern of N. pachyderma sinistral coiling, with peaks up to about 20% between MIS 30 and 28, and compare it to middle-late Quaternary records of the Sicily Channel and western Mediterranean.

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Impact of iceberg melting on Mediterranean thermohaline circulation during Heinrich events

Cited by 205 publications

References 64 publications

Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

Sedimentological imprint on subseafloor microbial communities in Western Mediterranean Sea Quaternary sediments

Ten Years of Paleoceanographic Studies at ODP Site 963 (Central Mediterranean Sea)

Orbital variations in planktonic foraminifera assemblages from the Ionian Sea during the Middle Pleistocene Transition

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