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| Registros recuperados: 18 | |
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| Gutscher, Marc-andre; Kopp, Heidrun; Krastel, Sebastian; Bohrmann, Gerhard; Garlan, Thierry; Zaragosi, Sebastien; Klaucke, Ingo; Wintersteller, Paul; Loubrieu, Benoit; Le Faou, Yann; San Pedro, Laurine; Dominguez, Stephane; Rovere, Marzia; De Lepinay, Bernard Mercier; Ranero, Cesar; Sallares, Valenti. |
| The detailed morphology and internal structure of the Calabrian accretionary wedge and adjacent Eastern Sicily margin are imaged in unprecedented detail by a combined dataset of multi-beam bathymetry and high-resolution seismic profiles. The bathymetric data represent the results of 6 recent marine geophysical surveys since 2010 as well as a compilation of earlier surveys presented as a 2 arc-sec (60 m) grid. Several distinct morpho-tectonic provinces are identified including: the deeply incised Malta–Hyblean Escarpment, numerous submarine canyons, broad regions of relatively flat seafloor dominated by fields of sediment waves, the gently undulating anticlinal fold-and-thrust belts of the external Calabrian accretionary wedge and the adjacent portion of... |
| Tipo: Text |
Palavras-chave: Subduction; Active faults; Eurasia-Africa plate boundary; Bathymetry; Seismic profiles; Accretionary wedge. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00366/47685/47853.pdf |
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| Renosh, Pannimpullath R.; Jourdin, Frederic; Charantonis, Anastase A.; Yala, Khalil; Rivier, Aurelie; Badran, Fouad; Thiria, Sylvie; Guillou, Nicolas; Leckler, Fabien; Gohin, Francis; Garlan, Thierry. |
| Hydro-sedimentary numerical models have been widely employed to derive suspended particulate matter (SPM) concentrations in coastal and estuarine waters. These hydro-sedimentary models are computationally and technically expensive in nature. Here we have used a computationally less-expensive, well-established methodology of self-organizing maps (SOMs) along with a hidden Markov model (HMM) to derive profiles of suspended particulate inorganic matter (SPIM). The concept of the proposed work is to benefit from all available data sets through the use of fusion methods and machine learning approaches that are able to process a growing amount of available data. This approach is applied to two different data sets entitled “Hidden” and “Observable”. The hidden... |
| Tipo: Text |
Palavras-chave: Suspended particulate inorganic matter; Self-organizing maps; Hidden Markov Model; Machine learning; English Channel; ROMS. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00415/52653/53511.pdf |
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| Gregoire, Gwendoline; Le Roy, Pascal; Ehrhold, Axel; Jouet, Gwenael; Garlan, Thierry. |
| This study details the sedimentary infilling of an original tidal-dominated estuary system during the final stage of the last marine transgression. The Bay of Brest is confined and connects the rivers Elorn and Aulne, to the sea of Iroise by a narrow strait encasing a well preserved paleo-channel. The compilation of high- and very-high-resolution bathymetric and seismic data, constrained by sediments datations, allows us to classify the paleo-morphology of the bay into three stepped domains: the paleo-valley floor surrounded by fluvial terraces, the central plateau, and the shallow embayments. Taking into account the main factors controlling the infilling, including sea-level rise, substratum morphology, and hydrodynamics, the stratigraphic scheme of the... |
| Tipo: Text |
Palavras-chave: Tide-dominated estuary; Incised-valley; Holocene infill; Seismic stratigraphy; Estuarine processes; Bay of Brest. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00358/46968/46883.pdf |
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| Kong, Eleonore; Zaragosi, Sebastien; Schneider, Jean-luc; Garlan, Thierry; Bachelery, Patrick; Sabine, Marjolaine; San Pedro, Laurine. |
| In the Ionian Sea, the subduction of the Nubia plate underneath the Eurasia plate leads to an important sediment remobilization on the Calabrian Arc and the Mediterranean Ridge. These events are often associated with earthquakes and tsunamis. In this study, we analyze gravity-driven deposits in order to establish their recurrence time on the Calabrian Arc and the western Mediterranean Ridge. Four gravity cores collected on ridges and slope basins of accretionary prisms record turbidites, megaturbidites, slumping and micro-faults over the last 330,000 years. These turbidites were dated by correlation with a hemipelagic core with a multi-proxy approach: radiometric dating, 18O, b* colour curve, sapropels and tephrochronology. The origin of the gravity-driven... |
| Tipo: Text |
Palavras-chave: Ionian Sea; Accretionary wedges; Palaeoearthquakes; Etna volcanism; Natural hazard; Turbidites. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00638/75012/75691.pdf |
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| Mazieres, Alais; Gillet, Herve; Castelle, Bruno; Mulder, Thierry; Guyot, Corentin; Garlan, Thierry; Mallet, Cyril. |
| In this study, the Capbreton canyon head, just off the coast, is investigated using high-resolution multibeam bathymetry datasets, sediment samples and numerical modeling. The HR bathymetry analysis reveals a morphological connection between the longshore trough and the head of the canyon. The analysis of recent sediment samples shows a clear correlation between the sediment of the canyon head and that of the nearshore. Hydrodynamic modeling (a coupled wave-flow model) shows that for high-energy waves, the rotational nature of surf-zone circulation reverses and wave-induced currents have the potential to transport large quantities of nearshore sands toward the canyon head. All these arguments support the assumption that the canyon head captures a part of... |
| Tipo: Text |
Palavras-chave: Longshore drift; Submarine canyon; Capbreton; Hydrodynamic modeling; Sediment transport. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00180/29118/27524.pdf |
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| Mengual, Baptiste; Cayocca, Florence; Le Hir, Pierre; Draye, Robin; Laffargue, Pascal; Vincent, Benoit; Garlan, Thierry. |
| Sea trials were performed on two zones with different fishing efforts on the continental shelf of the Bay of Biscay ('Grande-VasiSre' area of muddy sand) in order to assess particulate matter resuspension and seabed disturbances (i.e., penetration, reworking, grain size changes) induced by different types of trawls. Optical and acoustic measurements made in the water column indicate a significant trawling-induced resuspension mainly due to the scraping action of doors. It manifests as a highly dynamic turbid plume confined near the seabed, where suspended sediment concentrations can reach 200 mg l(-1). Concentration levels measured behind an "alternative" configuration (trawls with jumper doors instead of classical doors penetrating the sediment) are... |
| Tipo: Text |
Palavras-chave: Bottom trawling; Sedimentresuspension; Seabed disturbance; Erosion flux; Bay of Biscay. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00353/46428/51396.pdf |
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| Le Bot, Sophie; Trentesaux, Alain; Garlan, Thierry; Berne, Serge; Chamley, Hervé. |
| The present paper deals with dune dynamics in a zone of the Strait of Dover located in the sea lane running into the North Sea. The dunes, widespread in this 35-m depth area, are mobile sedimentary structures (up to 40 m.yr(-1)) that culminate at a maximum of 22 m depth and endanger navigation as well as submarine man-made structures (cables, pipelines). Single- and multibeam bathymetric data, coupled with seismic data, allow us to follow dune displacements over different time scales. A net bedload parting zone has been displayed and divides the area into two parts, SE and NW. However, according to the considered time-scale, dune movements present Variations in intensity and direction. Over a long-term period (decades), sedimentary dynamics fit the... |
| Tipo: Text |
Palavras-chave: Tempêtes; Dunes tidales; Dynamique sédimentaire; Détroit du Pas de Calais; Storms; Tidal dunes; Sedimentary dynamics; Strait of Dover. |
| Ano: 2000 |
URL: https://archimer.ifremer.fr/doc/2000/publication-519.pdf |
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| Mengual, Baptiste; Le Hir, Pierre; Cayocca, Florence; Garlan, Thierry. |
| This study describes the building of a common erosion law for fine sand and mud, mixed or not, in the case of a typical continental shelf environment, the Bay of Biscay shelf, characterized by slightly energetic conditions and a seabed mainly composed of fine sand and muddy sediments. A 3D realistic hydro-sedimentary model was used to assess the influence of the erosion law setting on sediment dynamics (turbidity, seabed evolution). A pure sand erosion law was applied when the mud fraction in the surficial sediment was lower than a first critical value, and a pure mud erosion law above a second critical value. Both sand and mud erosion laws are formulated similarly, with different parameters (erodibility parameter, critical shear stress and power of the... |
| Tipo: Text |
Palavras-chave: Sand-mud mixture erosion; Numerical modelling; Non-cohesive to cohesive transition. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00394/50588/51280.pdf |
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| Gregoire, Gwendoline; Ehrhold, Axel; Le Roy, Pascal; Jouet, Gwenael; Garlan, Thierry. |
| Long-studied with respect to its sedimentological features (1897), the Bay of Brest (Western Britanny, France) is a textbook example of a tide-dominated estuary. Characterised by macrotidal conditions, this estuary system is sheltered from the open sea (Iroise Sea) by a narrow strait that partitions the wave tide influences and continental/marine inputs. Sediments are supplied to the bay both by rivers (the Aulne and Elorn rivers) and by marine tidal currents. This study presents new analyses of detailed facies and morphological patterns, based on the integration of multisource data compiling seabed sampling, swath and LIDAR bathymetry, and backscatter imagery. The Main Map, at a scale of 1:90,000, contains (1) a sedimentological distribution using the... |
| Tipo: Text |
Palavras-chave: Morpho-sedimentological cartography; Tide-dominated; Estuary system; Estuarine sedimentation; Backscatter imagery; Bay of Brest. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44492/44224.pdf |
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| Meilland, Julie; Howa, Hélène; Hulot, Vivien; Demangel, Isaline; Salaun, Joëlle; Garlan, Thierry. |
| This study reports on species diversity and distribution of planktonic foraminifera (PF) at the Barents Sea Opening (BSO). PF populations living in late summer (collected by mean of stratified plankton tows) and recently settled individuals (sampled by interface corer) were studied and compared. High abundances reaching up to 400 ind.m−3 in tow samples and 8000 ind.cm−3 in surface sediments were recorded in the centre of the studied area while low abundances were observed in coastal areas, likely hampered by continental influences. The living and subfossil (i.e. core-top) assemblages are mainly composed of the four same species Neogloboquadrina pachyderma, Neogloboquadrina incompta, Turborotalita quinqueloba and Globigerinita uvula. The two species G.... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00591/70265/68323.pdf |
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| Caley, Thibaut; Zaragosi, S.; Bourget, Julien; Martinez, P.; Malaize, B.; Eynaud, F.; Rossignol, L.; Garlan, Thierry; Ellouz-zimmermann, Nadine. |
| The monsoon is one of the most important climatic phenomena: it promotes inter-hemispheric exchange of energy and affects the economical prosperity of several countries exposed to its seasonal seesaw. Previous studies in both the Indian and Asian monsoon systems have generally suggested a dominant northern hemispheric (NH) control on summer monsoon dynamics at the scale of suborbital-millennial climatic changes, while the forcing/response of Indian and Asian monsoons at the orbital scale remains a matter of debate. Here, six marine sediment cores distributed across the whole Arabian Sea are used to build a regional surface marine productivity signal. The productivity signal is driven by the intensity of Indian summer monsoon winds. Our results demonstrate... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00274/38492/36962.pdf |
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| Mignard, Salomé; Mulder, Thierry; Martinez, Philippe; Garlan, Thierry. |
| The effects of changes in slope gradient on deposition processes and architecture have been investigated in different deep-sea systems both in modern and ancient environments. However, the impact of subtle gradient changes (< 0.3∘) on sedimentary processes along deep-sea fans still needs to be clarified. The Ogooue Fan, located in the northeastern part of the Gulf of Guinea, extends over more than 550 km westwards of the Gabonese shelf and passes through the Cameroon volcanic line. Here, we present the first study of acoustic data (multibeam echosounder and 3.5 kHz, very high-resolution seismic data) and piston cores covering the deep-sea part of this West African system. This study documents the architecture and sedimentary facies distribution along... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61435/65154.pdf |
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| Registros recuperados: 18 | |
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