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| Registros recuperados: 11 | |
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| Maccali, Jenny; Hillaire-marcel, Claude; Ghaleb, Bassam; Ménabréaz, Lucie; Blénet, Aurélien; Edinger, Evan; Hélie, Jean-françois; Preda, Michel. |
| About 70 fossil and live-collected specimens of Desmophyllum dianthus were collected from steep rocky surfaces and time-averaged assemblages at their base (“coral graveyards”) in the southern Labrador Sea at depths ranging from ~1700 m (Orphan Knoll) to ~2200 m (Flemish Cap). Aside from stable isotope and mineralogical analysis, U-series and 14C age determinations were performed on the samples. Fossil corals from the coral graveyards display two principal age clusters corresponding respectively to the Holocene and Marine Isotope Stage (MIS) 5c intervals. Three samples lay outside these clusters, at ~13.5 ka (Bølling-Allerød), ~ 64 ka (MIS 3) and at ~181 ka (MIS 7a). The clusters are thought to record intervals with both i) high food availability, either... |
| Tipo: Text |
Palavras-chave: Deep-sea corals; Aragonite corals; Labrador Sea; Radiocarbon; U-series dating. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00623/73496/72790.pdf |
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| Rattan, Sanjay; Myers, Paul G.; Treguier, Anne-marie; Theetten, Sebastien; Biastoch, Arne; Boening, Claus. |
| Model drift in the Labrador Sea in eddy permitting model simulations is examined using a series of configurations based on the NEMO numerical framework. There are two phases of the drift that we can identify, beginning with an initial rapid 3-year period, associated with the adjustment of the model from its initial conditions followed by an extended model drift/adjustment that continued for at least another decade. The drift controlled the model salinity in the Labrador Sea, over-riding the variability. Thus, during this initial period, similar behavior was observed between the inter-annually forced experiments as with perpetual year forcing. The results also did not depend on whether the configuration was global, or regional North Atlantic Ocean. The... |
| Tipo: Text |
Palavras-chave: Numerical modelling; Labrador Sea; Model salinity drift; Boundary currents; Eddy-permitting models. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12411/9226.pdf |
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| Rashid, H; Hesse, R; Piper, Djw. |
| An additional Heinrich ice-rafting event is identified between Heinrich events 5 and 6 in eight cores from the Labrador Sea and the northwest Atlantic Ocean. It is characterized by sediment rich in detrital carbonate (40% CaCO3) with high concentration of floating dropstones, high coarse-fraction (% > 150 mum) content, and has a sharp contact with the underlying but grades into the overlying hemipelagic sediment. It also shows lighter delta(18)O(Npl) values, indicating freshening due to iceberg rafting and/or meltwater discharge. This event is correlated with Dansgaard-Oeschger event 14 and interpreted as an additional Heinrich event, H5a. The thickness of H5a in the Labrador Sea reaches up to 220 cm. This additional Heinrich event has also been... |
| Tipo: Text |
Palavras-chave: Heinrich events; Nepheloid flow deposits; GISP2; Dansgaard-Oeschger cycle; Labrador Sea. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00225/33658/32098.pdf |
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| Andrews, J. T.; Barber, D. C.; Jennings, A. E.; Eberl, D. D.; Maclean, B.; Kirby, M. E.; Stoner, J. S.. |
| Core HU97048-007PC was recovered from the continental Labrador Sea slope at a water depth of 945?m, 250?km seaward from the mouth of Cumberland Sound, and 400?km north of Hudson Strait. Cumberland Sound is a structural trough partly floored by Cretaceous mudstones and Paleozoic carbonates. The record extends from similar to 10 to 58?ka. On-board logging revealed a complex series of lithofacies, including buff-colored detrital carbonate-rich sediments [Heinrich (H)-events] frequently bracketed by black facies. We investigate the provenance of these facies using quantitative X-ray diffraction on drill-core samples from Paleozoic and Cretaceous bedrock from the SE Baffin Island Shelf, and on the?<?2-mm sediment fraction in a transect of five cores from... |
| Tipo: Text |
Palavras-chave: Baffin Bay; Detrital carbonate (DC-) events; Heinrich events; Labrador Sea; Laurentide Ice Sheet. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00265/37644/35823.pdf |
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| Wolf, Mitchell K.; Hamme, Roberta C.; Gilbert, Denis; Yashayaev, Igor; Thierry, Virginie. |
| Deep water formation supplies oxygen-rich water to the deep sea, spreading throughout the ocean by means of the global thermohaline circulation. Models suggest that dissolved gases in newly formed deep water do not come to equilibrium with the atmosphere. However, direct measurements during wintertime convection are scarce, and the controls over the extent of these disequilibria are poorly quantified. Here we show that, when convection reached deeper than 800 m, oxygen in the Labrador Sea was consistently undersaturated at -6.1% to -7.6% at the end of convection. Deeper convection resulted in greater undersaturation, while convection ending later in the year resulted in values closer to equilibrium, from which we produce a predictive relationship. We use... |
| Tipo: Text |
Palavras-chave: Oxygen saturation; Convection; Argo; Labrador Sea; Deep water formation. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00442/55329/56829.pdf |
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| Rasmussen, Tl; Oppo, Dw; Thomsen, E; Lehman, Sj. |
| [1] Results from two deep sea cores from northeast of Newfoundland at 1251 and 2527 m water depth, respectively, indicate that during the time period from 160,000 to 10,000 years BP, ice rafting events in the Labrador Sea were accompanied by rapid variations in deep and surface water circulation. Twelve ice-rafting events occurred, each coinciding with high concentrations of detrital carbonate and oxygen isotopic depletion of both surface and bottom waters. Eleven of these can be correlated with the North Atlantic Heinrich events H1-H11. The remaining very conspicuous ice-rafting event took place early in MIS substage 5e, at a time when the planktic faunal assemblage suggests marked warming of the sea surface. In the shallower core, benthic delta(13)C... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Labrador Sea; Ice rafting; Foraminifera; Last climate cycle. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00496/60768/65083.pdf |
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| Jansson, Kn; Kleman, J. |
| [1] In this paper we analyze drainage routes and estimate fluxes of meltwater released from Labrador-Ungava glacial lakes into the Labrador Sea, Ungava Bay, and Hudson Bay between 7.5 and 6.0 kyr BP (8.4 - 7.0 calendar (cal) years ka). The analysis and estimates are based on landform- based reconstructions of the Laurentide Ice Sheet ( LIS) decay pattern and the associated glacial lake evolution. Geomorphological data constraining the spatial extent of glacial lakes are coupled to a digital terrain model for meltwater volume calculations. The LIS ice recession between 7.5 and 6.0 kyr BP led to the formation of a large number of glacial lakes, which drained in approximately 30 meltwater pulses, with fluxes exceeding 0.015 Sv (1 Sv = 10(6) m(3) s(-1)), into... |
| Tipo: Text |
Palavras-chave: Laurentide Ice Sheet; Glacial lake; Labrador Sea. |
| Ano: 2004 |
URL: https://archimer.ifremer.fr/doc/00504/61613/65521.pdf |
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| Cossa, Daniel; Heimburger, L. E.; Sonke, J. E.; Planquette, H.; Lherminier, Pascale; Garcia-ibanez, Maria Isabel; Perez, Ff; Sarthou, G.. |
| The Labrador Sea links the Arctic and North Atlantic oceans and constitutes one of the main entrances of atmospheric inputs into the Ocean's interior. We report here the first high-resolution Hg distribution pattern along a transect from Greenland to Labrador coasts sampled after the 2014 winter convection. Total Hg concentrations in unfiltered (HgTUNF) samples ranged from 0.25 pmol L− 1 to 0.67 pmol L− 1 averaging 0.44 ± 0.10 pmol L− 1 (n = 113, 1σ). Concentrations in filtered samples (HgTF, < 0.45 μm) represented from 62 to 92% of the HgTUNF and exhibited a similar distribution. High HgTUNF concentrations were found (i) in the waters of the Labrador Current, which receive desalted waters from the Canadian Arctic Archipelago, and (ii) in the waters... |
| Tipo: Text |
Palavras-chave: Labrador Sea; Mercury; North Atlantic. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00411/52207/52929.pdf |
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| Hesse, Reinhard; Khodabakhsh, Saeed. |
| Heinrich layers (H-layers) are distinct, decimetre to centimetre thick layers of ice-rafted debris (IRD) that were deposited in the North Atlantic during the Late and middle Pleistocene. H-layers (H-layers) are characterized by high detrital carbonate and low foraminifera contents. In the Labrador Sea, H-layers reach metre thickness in some proximal core sites near the iceberg source of the Hudson Strait ice stream and show five distinct depositional facies involving sediment lofting and low-density turbidity currents as sediment delivery processes besides ice rafting. Thick massive ice-rafted layers (type I H-layers) occur in the most proximal parts of H-layer 3 and older H-layers. Within 300 km distance from the assumed Hudson Strait ice stream terminus,... |
| Tipo: Text |
Palavras-chave: Heinrich layers; Labrador Sea; Ice rafting; Sediment lofting; Turbidity currents; Ice-proximal environments. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00341/45214/44639.pdf |
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| Registros recuperados: 11 | |
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