|
|
|
| Registros recuperados: 62 | |
|
|
| Toucanne, Samuel; Zaragosi, S.; Bourillet, Jean-francois; Gibbard, P. L.; Eynaud, F.; Giraudeau, J.; Turon, J. L.; Cremer, M.; Cortijo, E.; Martinez, P.; Rossignol, L.. |
| The correlation of continental sedimentary records with the marine isotope stratigraphy is a challenge of central importance in Quaternary stratigraphy, particularly in Western Europe where long records of glaciation on land areas are particularly rare. Here we demonstrate for the first time the interrelationship of events during the last 1.2 Ma in an ocean-sediment core from the Bay of Biscay (NE Atlantic), SW of the Channel. The identification of discharge variations from tributary river systems to the 'Fleuve Manche' palaeoriver during glacio-eustatic sea-level lowstands demonstrates the correlation of the marine sediment stratigraphy to the expansion and recession of the European ice-sheets. The amplitude and chronology of European ice-sheet... |
| Tipo: Text |
Palavras-chave: Middle pleistocene transition; Ice sheet dynamics; Sea level; Climate change; North Atlantic; English channel; Heinrich events; Fleuve manche; Deep; Origin. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6956.pdf |
| |
|
| |
|
|
| Robinson, Craig D.; Webster, Lynda; Martinez-gomez, Concepcion; Burgeot, Thierry; Gubbins, Matthew J.; Thain, John E.; Vethaak, A. Dick; Mcintosh, Alistair D.; Hylland, Ketil. |
| Understanding the status of contaminants in the marine environment is a requirement of European Union Directives and the Regional Seas Conventions, so that measures to reduce pollution can be identified and their efficacy assessed. The international ICON workshop (Hylland et al., in this issue) was developed in order to test an integrated approach to assessing both contaminant concentrations and their effects. This paper describes and assesses the concentrations of trace metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in sediments, mussels, and fish collected from estuarine, coastal and offshore waters from Iceland to the Mediterranean Sea. For organic contaminants, concentrations progressively increased from Iceland, to the... |
| Tipo: Text |
Palavras-chave: Integrated assessment; ICES; North Atlantic; North Sea; Baltic Sea; Mediterranean Sea; Polycyclic aromatic hydrocarbons (PAHs); Polychlorinated biphenyls (PCBs); Trace metals; Environmental monitoring. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00324/43520/43051.pdf |
| |
|
|
| Farmer, Elizabeth J.; Chapman, Mark R.; Andrews, Julian E.. |
| A high-resolution record of Mg/Ca ratios from the planktonic foraminifer Globigerina bulloides has been produced for IMAGES core MD99-2251 from the subpolar North Atlantic. The record extends from the Younger Dryas-Preboreal transition through the Holocene at similar to 70 year resolution, with a more detailed section at similar to 20 year resolution through the interval encompassing the major cooling episode 8200 years ago. Mg/Ca derived temperatures show significant variations through the Holocene, with surface temperatures ranging from similar to 8 to 13 degrees C. The onset of the Holocene is marked by an abrupt warming, with a further increase in early Holocene temperatures occurring prior to 9.5 ka. This is followed by a mid-Holocene period of cooler... |
| Tipo: Text |
Palavras-chave: Planktonic foraminifera; Mg/Ca; G. bulloides; North Atlantic; Holocene. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00236/34760/33396.pdf |
| |
|
|
| Macgilchrist, Graeme A.; Marshall, David P.; Johnson, Helen L.; Lique, Camille; Thomas, Matthew. |
| Ventilation of the upper ocean plays an important role in climate variability on interannual to decadal timescales by influencing the exchange of heat and carbon dioxide between the atmosphere and ocean. The turbulent nature of ocean circulation, manifest in a vigorous mesoscale eddy field, means that pathways of ventilation, once thought to be quasi-laminar, are in fact highly chaotic. We characterize the chaotic nature of ventilation pathways according to a nondimensional filamentation number, which estimates the reduction in filament width of a ventilated fluid parcel due to mesoscale strain. In the subtropical North Atlantic of an eddy-permitting ocean model, the filamentation number is large everywhere across three upper ocean density... |
| Tipo: Text |
Palavras-chave: Ventilation; North Atlantic; Thermocline; Chaos; Mesoscale eddies; Lagrangian trajectories. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00410/52104/52807.pdf |
| |
|
| |
|
| |
|
|
| Lambert, C.; Authier, M.; Doray, Mathieu; Doremus, G.; Spitz, J.; Ridoux, V.. |
| Most oceanographic systems, especially shelf ecosystems, are characterised by interannual variability in the timing, extent and intensity of their seasonal patterns. Such interannual variations have important consequences on top predator habitat preferences. Capitalising on oceanographic surveys performed every spring since 2004 in the Bay of Biscay (BoB), this study explored interannual variations in habitat preferences exhibited by five mobile top predator species: bottlenose and common dolphins, auks, fulmars and northern gannets. We expected to find species with similar habitat preferences every year or species exhibiting important variability in their habitat preferences. First, we identified with a Principal Component Analysis (PCA) three different... |
| Tipo: Text |
Palavras-chave: Habitat preference; Temporal variability; Cetaceans; Seabirds; North Atlantic; Bay of Biscay. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00431/54226/55549.pdf |
| |
|
| |
|
| |
|
| |
|
|
| Rochet, Marie-joelle; Trenkel, Verena; Carpentier, Andre; Coppin, Franck; Gil De Sola, Luis; Leaute, Jean-pierre; Mahe, Jean-claude; Maiorano, Porzia; Mannini, Alessandro; Murenu, Matteo; Piet, Gerjan; Politou, Chrissi-yianna; Reale, Bruno; Spedicato, Maria-teresa; Tserpes, George; Bertrand, Jacques. |
| P>1. The development of ecosystem approaches to environmental management implies the need to account for multiple pressures on ecosystems. Trends in multiple metrics that respond differently to changes in major environmental pressures need to be combined to evaluate the impacts of fishing and environmental changes on fish communities. 2. An exploited fish community is viewed as a three-level food chain in which the two upper levels, or functional groups, are targeted by fishing fleets, while the lowest level is subject to environmental variation. Qualitative modelling is used to predict changes at the two upper levels, that is, top-down vs. bottom-up perturbations. Abundance and length metrics are calculated from survey data for 14 Mediterranean and... |
| Tipo: Text |
Palavras-chave: Bottom-up control; Community metrics; Compensation; Ecosystem approach to fisheries; Ecosystem assessment; Functional groups; Groundfish community; Mediterranean; North Atlantic; Top-down control. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00008/11925/8637.pdf |
| |
|
| |
|
| |
|
|
| Irvali, Nil; Ninnemann, Ulysses S.; Kleiven, Helga (kikki) F.; Galaasen, Eirik V.; Morley, Audrey; Rosenthal, Yair. |
| High-resolution lithic and sea surface climate records are used to portray the progression of North Atlantic climate, hydrography, and Greenland Ice Sheet (GIS) activity through the peak of Marine Isotope Stage (MIS) 5e into the last glacial inception. We use Eirik Drift sediment core MD03-2664 (57°26.34′N, 48°36.35′W), recovered south of Greenland, strategically located to monitor fluctuations in GIS extent and iceberg calving events. Our results show that a significant amount of ice-rafted debris (IRD) was present during the early MIS 5e, until gradually tapering off by 122 kyr BP due to a diminishing GIS. Sea surface temperatures (SSTs) in the northern subpolar gyre reached peak values early in MIS 5e coinciding with peak insolation. Regional cooling... |
| Tipo: Text |
Palavras-chave: Eirik drift; Greenland Ice Sheet; North Atlantic; Last interglacial; Glacial inception; Multi-proxy. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00349/46009/45681.pdf |
| |
|
|
| Small, David; Austin, William; Rinterknecht, Vincent. |
| A sediment core from the north-east North Atlantic contains high-resolution co-registered foraminiferal O-18 and ice-rafted detritus (IRD) records for the last deglaciation. These reveal a distinct ice-rafting event that occurred at the time of Greenland Interstade 1d (GI-1d), a feature also seen in other high-resolution cores from the North Atlantic. The occurrence of a geographically widespread peak in IRD at ice distal sites at a time when increased freshwater flux to the surface ocean is inferred to have caused rapid cooling suggests a mechanistic link between the processes, analogous to the Younger Dryas (GS-1) cooling episode. The general absence of IRD at southern locations at other times during GI-1 when the flux of icebergs from surviving ice... |
| Tipo: Text |
Palavras-chave: Deglaciation; Hydrography; Ice-rafted detritus; North Atlantic; Sea surface temperature. |
| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00291/40180/39238.pdf |
| |
|
|
| Desbruyeres, D.g.; Mcdonagh, E. L.; King, B. A.; Garry, F. K.; Blaker, A. T.; Moat, B. I.; Mercier, Herle. |
| The vertical structure of temperature trends in the northeastern Atlantic (NEA) is investigated using a blend of Argo and hydrography data. The representativeness of sparse hydrography sampling in the basin mean is assessed using a numerical model. Between 2003 and 2013, the NEA underwent a strong surface cooling (0–450 m) and a significant warming at intermediate and deep levels (1000 m to 3000 m) that followed a strong cooling trend observed between 1988 and 2003. During 2003–2013, gyre-specific changes are found in the upper 1000 m (warming and cooling of the subtropical and subpolar gyres, respectively), while the intermediate and deep warming primarily occurred in the subpolar gyre, with important contributions from isopycnal heave and water mass... |
| Tipo: Text |
Palavras-chave: North Atlantic; Temperature; Observations; Hiatus. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00236/34677/33026.pdf |
| |
|
|
| Gherardi, Jeanne Marie; Labeyrie, L.; Nave, S.; Francois, R.; Mcmanus, J. F.; Cortijo, E.. |
| Studies from the subtropical western and eastern Atlantic Ocean, using the Pa-231/Th-230 ratio as a kinematic proxy for deep water circulation, provided compelling evidence for a strong link between climate and the rate of meridional overturning circulation (MOC) over the last deglaciation. In this study, we present a compilation of existing and new sedimentary Pa-231/Th-230 records from North Atlantic cores between 1710 and 4550 m water depth. Comparing sedimentary Pa-231/Th-230 from different depths provides new insights into the evolution of the geometry and rate of deep water formation in the North Atlantic during the last 20,000 years. The Pa-231/Th-230 ratio measured in upper Holocene sediments indicates slow water renewal above similar to 2500 m and... |
| Tipo: Text |
Palavras-chave: MOC; North Atlantic; Deglaciation; 231Pa/230Th. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00233/34468/32855.pdf |
| |
|
|
| Poitevin, Pierre; Thébault, Julien; Siebert, Valentin; Donnet, Sébastien; Archambault, Philippe; Doré, Justine; Chauvaud, Laurent; Lazure, Pascal. |
| The Northwest Atlantic is a key region with an essential role in global climate regulation, redistributing heat and influencing the carbon cycle. However, little is known about its evolution before 1950, mainly because of the lack of long-term instrumental measurements. The hard parts of long-lived marine biota hold the potential to extend instrumentally derived observation by several decades or centuries and enhance our understanding of global climate processes. Here, we investigate the effects of local, regional, and large-scale climate variability on the marine bivalve, Arctica islandica (Linnaeus, 1767) from Saint-Pierre and Miquelon (SPM). This archipelago lies at the boundary zone between the cold Labrador Current in the north and the warm Gulf... |
| Tipo: Text |
Palavras-chave: Arctica islandica; Paleoecology; North Atlantic; Sub polar gyre; Labrador current; Bivalve; Sclerochronology; Climate change. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62050/66198.pdf |
| |
|
|
| Solignac, S; Giraudeau, J; De Vernal, A. |
| Holocene records of sea surface conditions in the western Nordic seas were obtained from quantitative reconstructions based on dinoflagellate cyst assemblages. Two sediment cores from the east Greenland and the north Iceland shelves provide a detailed account of the long- and short-term dynamics of the opposing flows of Arctic versus Atlantic waters. Both marker species and quantitative reconstructions depict an overall trend toward warmer winter temperatures, saltier surface waters, and decreased sea ice extent. The latter is supported by a close relationship between relative abundances of an Atlantic dinocyst species, Nematosphaeropsis labyrinthus, and ice-rafted debris (IRD) records. We propose that the late Holocene increased IRD delivery in the... |
| Tipo: Text |
Palavras-chave: Holocene; North Atlantic; Sea-surface conditions. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34573/33124.pdf |
| |
| Registros recuperados: 62 | |
|
|
|
