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| Registros recuperados: 15 | |
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| Toucanne, Samuel; Jouet, Gwenael; Ducassou, Emmanuelle; Bassetti, Maria-angela; Dennielou, Bernard; Minto'O, Charlie Morelle Angue; Lahmi, Marjolaine; Touyet, Nicolas; Charlier, Karine; Lericolais, Gilles; Mulder, Thierry. |
| Sortable silt particle-size data and stable isotope analyses from the Corsica Trough, western Mediterranean Sea, provide a continuous palaeoceanographic record of the inflow, ventilation and vertical fluctuations of the Levantine Intermediate Water (LIW) in the northern Tyrrhenian Sea for the last 130,000 years. The results presented herein reveal that climate changes drive the Mediterranean intermediate circulation on Milankovitch to millennial time-scales. Intensified intermediate inflow and ventilation in the Corsica Trough occurred throughout the last glacial interval, with a cold / faster – warm / slower pattern existing between the Dansgaard-Oeschger climatic oscillations (including Heinrich events) and the LIW variability. By contrast, a weak... |
| Tipo: Text |
Palavras-chave: Levantine Intermediate Water; Mediterranean Sea; Thermohaline circulation; Palaeoceanography. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00054/16506/14023.pdf |
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| Bauch, Henning A.; Erlenkeuser, Helmut. |
| Sediment cores from the Norwegian Sea were studied to evaluate interglacial climate conditions of the marine isotope stage 5e (MIS 5e). Using planktic forminiferal assemblages as the core method, a detailed picture of the evolution of surface water conditions was derived. According to our age model, a step-like deglaciation of the Saalian ice sheets is noted between ca. 135 and 124.5 Kya, but the deglaciation shows little response with regard to surface ocean warming. From then on, the rapidly increasing abundance of subpolar forminifers, concomitant with decreasing iceberg indicators, provides evidence for the development of interglacial conditions sensu stricto (5e-ss), a period that lasted for about 9 Ky. As interpreted from the foraminiferal records,... |
| Tipo: Text |
Palavras-chave: Holocene; Last interglacial; Nordic seas; Palaeoceanography; Planktic foraminifers; Stable isotopes. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34811/33316.pdf |
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| Zurita, G.. |
| Cerca de 200 muestras de cuatro muestreadores de pistón provenientes de ambos flancos de la Cordillera Submarina Carnegie, Pacífico Ecuatorial Oriental, fueron analizadas. Cocolitofóridos fueron usados para el estudio bioestratigráfico. La presencia o ausencia de las distintas especies no concuerda con los ciclos climáticos. Las variaciones del contenido de carbonato de calcio, obedecen a mayor o menor disolución durante épocas no glaciales o glaciales respectivamente. La preservación de cocolitos y el aparente alto contenido del carbonato de calcio antes de 251.000 años sugiere poca variación de condiciones climáticos, correspondiendo a una menor disolución de material calcáreo. |
| Tipo: Journal Contribution |
Palavras-chave: Biostratigraphy; Palaeoceanography. |
| Ano: 1987 |
URL: http://hdl.handle.net/1834/2141 |
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| De Deckker, P.; Moros, M.; Perner, K.; Blanz, T.; Wacker, L.; Schneider, R.; Barrows, T.t.; O’loingsigh, T.; Jansen, E.. |
| The Quaternary is well known for being a period of the geological record that saw significant and alternating climatic fluctuations. Here, we concentrate on the last 94 millennia that saw Australia and its surrounding seas undergo significant environmental changes. Importantly also it is during that this period of time includes the arrival and settlement of humans in Australia. Following on from Marine Isotopic Stage 4 (MIS4) that saw, over the period of 71-59 ka BP, a significant eustatic sea level drop (similar to 100 m), low sea-surface temperatures as well as glacial conditions on land, Australia experienced wet conditions again, but eventually progressively entered into a glacial phase. By then, humans had arrived on this large continent and later the... |
| Tipo: Text |
Palavras-chave: Oceanic fronts; Leeuwin Current; Foraminifer faunal analysis; Marine isotopic stages; Last Glacial Maximum; Palaeoceanography; Sea-surface temperature; Moraines; Modern analogue technique; Subantarctic Front; G. ruber. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00657/76931/78127.pdf |
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| Nilsson-kerr, Katrina; Anand, Pallavi; Holden, Philip B.; Clemens, Steven C.; Leng, Melanie J.. |
| Most of Earth’s rain falls in the tropics, often in highly seasonal monsoon rains, which are thought to be coupled to the inter-hemispheric migrations of the Inter-Tropical Convergence Zone in response to the seasonal cycle of insolation. Yet characterization of tropical rainfall behaviour in the geologic past is poor. Here we combine new and existing hydroclimate records from six large-scale tropical regions with fully independent model-based rainfall reconstructions across the last interval of sustained warmth and ensuing climate cooling between 130 to 70 thousand years ago (Marine Isotope Stage 5). Our data-model approach reveals large-scale heterogeneous rainfall patterns in response to changes in climate. We note pervasive dipole-like tropical... |
| Tipo: Text |
Palavras-chave: Palaeoceanography; Palaeoclimate. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79705/82497.pdf |
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| Chalk, T. B.; Foster, G. L.; Wilson, P. A.. |
| The origin and carbon content of the deep water mass that fills the North Atlantic Basin, either Antarctic Bottom Water (AABW) or North Atlantic Deep Water (NADW) is suggested to influence the partitioning of CO2 between the ocean and atmosphere on glacial-interglacial timescales. Fluctuations in the strength of Atlantic meridional overturning circulation (AMOC) have also been shown to play a key role in global and regional climate change on timescales from annual to millennial. The North Atlantic is an important and well-studied ocean basin but many proxy records tracing ocean circulation in this region over the last glacial cycle are challenging to interpret. Here we present new B/Ca-[CO32-] and boron isotope-pH data from sites spanning the North... |
| Tipo: Text |
Palavras-chave: Boron; Geochemistry; Palaeoceanography; Carbonate system; Glacial; Atlantic. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00496/60812/64631.pdf |
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| Goineau, A.; Fontanier, Christophe; Mojtahid, M.; Fanget, Anne-sophie; Bassetti, M-a.; Berne, Serge; Jorissen, F.. |
| Dead benthic foraminiferal faunas (> 150 μm) from the Rhône prodelta (Gulf of Lions, NW Mediterranean) were analysed at 41 stations (15–100 m water depth) sampled in June 2005 and September 2006, and compared to the living faunas investigated during previous studies at the same stations. The comparison between dead and living assemblages enhances the understanding of taphonomic processes that may modify the composition of the dead faunas in this area. We observed a loss of individuals from living to dead assemblages of species characterised by a fairly fragile test and therefore more prone to fragmentation or dissolution (e.g., Bolivina alata, Quinqueloculina tenuicollis). Allochthonous dead and/or live specimens may be transported to some parts of the... |
| Tipo: Text |
Palavras-chave: Benthic foraminifera; Rhone prodelta; Taphonomy; Thanatofacies; Palaeoceanography. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38399/36725.pdf |
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| Pascual, A.; Rodríguez-lázaro, J.; Martínez-garcía, B.; Varela, Z.. |
| Benthic foraminifera assemblages from a sedimentary core (PP10-12; 701 mwd) from the SE Bay of Biscay allow us to trace palaeoceanographic and palaeoclimatic changes occurred in this region during mid MIS 3 (Marine Isotope Stage 3) and MIS 1 interval (37–2.4 ka BP). Results are based on 176 benthic foraminifera species considering their ecology, the difference between autochthonous/allochthonous, preservation and oxygen rates, thus evidencing climatic and oceanographic events. MIS 3 is characterised by waters with a dominance of Cassidulina laevigata and Uvigerina peregrina. By the end of this interval, waters became colder and less oxygenated indicated by the occurrence of Melonis affinis. These conditions persisted at the beginning of MIS 2. The Heinrich... |
| Tipo: Text |
Palavras-chave: Palaeoclimatology; Palaeoceanography; Benthic foraminifera; MIS 3-MIS 1; Bay of Biscay. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73910/73242.pdf |
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| Skinner, L.; Mccave, I. N.; Carter, L.; Fallon, S.; Scrivner, A. E.; Primeau, F.. |
| It has been proposed that the ventilation of the deep Pacific carbon pool was not significantly reduced during the last glacial period, posing a problem for canonical theories of glacial-interglacial CO2 change. However, using radiocarbon dates of marine tephra deposited off New Zealand, we show that deep(>2000 m) and shallow sub-surface ocean-atmosphere C-14 age offsets (i.e. 'reservoir-' or 'ventilation' ages) in the southwest Pacific increased by similar to 1089 and 337 yrs respectively, reaching similar to 2689 and similar to 1037 yrs during the late glacial. A comparison with other radiocarbon data from the southern high-latitudes suggests that broadly similar changes were experienced right across the Southern Ocean. If, like today, the Southern... |
| Tipo: Text |
Palavras-chave: Radiocarbon; Ocean ventilation; Carbon cycling; Palaeoceanography. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00352/46279/46041.pdf |
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| Major, Candace O.; Goldstein, Steven L.; Ryan, William B.f.; Lericolais, Gilles; Piotrowski, Alexander M.; Hajdas, Irka. |
| The Black Sea was an inland lake during the last ice age and its sediments are an excellent potential source of information on Eurasian climate change, showing linkages between regionally and globally recognized millennial-scale climate events of the last deglaciation. Here, we detail changes from the last glacial maximum (LGM) through the transition to an anoxic marginal sea using isotopic (strontium and oxygen) and trace element (Sr/Ca) ratios in carbonate shells, which record changing input sources and hydrologic conditions in the basin and surrounding region. Sr isotope records show two prominent peaks between similar to 18 and 16 ka BP cal, reflecting anomalous sedimentation associated with meltwater from disintegrating Eurasian ice sheets that... |
| Tipo: Text |
Palavras-chave: Sea level changes; Black Sea; Deglaciation; Glaciation; Palaeoclimate; Palaeoceanography. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2006.pdf |
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| Frings, Patrick J.; Clymans, Wim; Fontorbe, Guillaume; De La Rocha, Christina L.; Conley, Daniel J.. |
| The silicon isotope composition of biogenic silica (delta Si-30(BSi)) in the ocean is a function of the delta Si-30 of the available dissolved Si (DSi; H2SiO4), the degree of utilisation of the available DSi, and, for some organisms, the concentration of DSi. This makes delta Si-30(BSi) in sediment archives a promising proxy for past DSi concentrations and utilisation. At steady-state, mean delta Si-30(BSi) must equal a weighted average of the inputs, the majority of which are of continental origin. Variation in the functioning of the continental Si cycle on timescales similar to the residence time of DSi in the ocean (similar to 10 ka) may therefore contribute to downcore variability in delta Si-30(BSi) on millennial or longer time-scales. The direction... |
| Tipo: Text |
Palavras-chave: Global silicon cycle; Biogenic silica; Silicon isotopes; LGM; Palaeoceanography; Biogeochemical cycling. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00421/53252/54714.pdf |
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| Toyofuku, Takashi; Duros, Pauline; Fontanier, Christophe; Mamo, Briony; Bichon, Sabrina; Buscail, Roselyne; Chabaud, Gerard; Deflandre, Bruno; Goubet, Sarah; Gremare, Antoine; Menniti, Christophe; Fujii, Minami; Kawamura, Kiichiro; Koho, Karoliina Annika; Noda, Atsushi; Namegaya, Yuichi; Oguri, Kazumasa; Radakovitch, Olivier; Murayama, Masafumi; De Nooijer, Lennart Jan; Kurasawa, Atushi; Ohkawara, Nina; Okutani, Takashi; Sakaguchi, Arito; Jorissen, Frans; Reichart, Gert-jan; Kitazato, Hiroshi. |
| On March 11th, 2011 the Mw 9.0 2011 Tohoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by... |
| Tipo: Text |
Palavras-chave: Palaeoceanography; Biodiversity. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00248/35914/34453.pdf |
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| Foubert, A.; Van Rooij, D.; Blamart, D.; Henriet, J.-p.. |
| Three provinces, characterized by the presence of carbonate mounds interpreted as cold-water coral banks have been reported in Porcupine Seabight, SW of Ireland and were recently subjected to many detailed studies. This contribution discusses the use of X-ray imagery and physical properties in deciphering palaeoceanographic, sedimentological and biological processes. Physical property core logging and X-ray imagery are used to identify and describe sedimentation regimes and so their respective palaeoceanographic and palaeoclimatological settings in two mound provinces, respectively the Belgica mound province and the Magellan mound province. Both provinces show at present time clear differences in the hydrodynamic environment. This study confirms that also... |
| Tipo: Text |
Palavras-chave: X-ray imagery; Physical core logging; Carbonate mounds; Porcupine Basin; Palaeoceanography. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00233/34451/32916.pdf |
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| Registros recuperados: 15 | |
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