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| Registros recuperados: 45 | |
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| Rakotonarivo, Sandrine; Legris, Michel; Desmare, Rozenn; Sessarego, Jean-pierre; Bourillet, Jean-francois. |
| This paper investigates the forward modeling of chirp-sonar data for the quantitative characterization of marine subbottom sediment between 1 and 10 kHz. The forward modeling, based on a transfer function approach, included impacts of layering or impedance mismatch, attenuation, roughness, and transitional layers, i.e., continuous impedance variations. The presented approach provided the best compromise between the number of available geoacoustic parameters from chirp-sonar data and the subbottom modeling accuracy. The forward model was tested on deep-sea chirp-sonar data acquired at a central frequency of 3.5 kHz. Comparisons between synthetic and experimental seismograms showed good agreement for the first 15 m of buried layers. Performance of the... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00039/15053/12380.pdf |
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| Bourillet, Jean-francois; De Chambure, Laurent; Loubrieu, Benoit. |
| Les coraux d’eau froide, contrairement aux coraux tropicaux, n’ont pas besoin de lumière et peuvent se développer en profondeur. Les espèces constructrices comme Lophelia pertusa et Madrepora occulata ont une distribution mondiale et sont présentes de la Norvège à la Grèce sous forme de monts carbonatés ou de récifs. Menacés par l’évolution des conditions environnementales et les actions anthropiques, les coraux d’eau froide sont actuellement classés comme écosystème vulnérable par plusieurs institutions internationales. Dans les eaux européennes, les indicateurs pour mesurer l’impact des pêcheries et l’efficacité des mesures de protection manquent encore. Le projet européen CoralFISH vise à étudier l’interaction entre les coraux, les poissons et les... |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00320/43162/42719.pdf |
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| Bourillet, Jean-francois; Zaragosi, S; Mulder, T. |
| The sedimentary infill of the Bay of Biscay off Ireland, UK, France and Spain took place in four phases. The last one (35 Ma to present) is characterised by gravitational, pelagic, contouritic and glacigenic processes leading to the setup of three deep sea systems. To the North, the Celtic and Armorican fans are fed by a "canyon-dominated" margin and its connection with the "Manche" palaeoriver, which drained a large area of western Europe. To the South, the Cap-Ferret fan results from the evolution of a "tectonic-dominated" margin and the erosion of the Pyrenee mountains. |
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Palavras-chave: Sedimentology; Geomorphologya; Deep sea; Bay of Biscay; French Atlantic margin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2137.pdf |
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| Paquet, Fabien; Menier, David; Estournes, Guilhem; Bourillet, Jean-francois; Leroy, Pascal; Guillocheau, Francois. |
| High-resolution seismic data have been acquired in June 2008 on the Armorican Shelf (AS), in the northern Bay of Biscay, in order to reassess its stratigraphic architecture in detail and to study the impact of eustasy, tectonic and sediment delivery on the margin sedimentary record. Several profiles show fluvial-type incisions of several tens of meters (up to 54 m) associated to a widespread erosion surface. Several hypotheses are proposed for the stratigraphic position of this surface and incisions. We suggest Middle to Late Miocene age. Considering the relatively quiescent tectonic activity of the margin, we infer that the relative sea-level fall responsible of aerial incision on the Miocene shelf is eustasy-related. We propose the attested... |
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Palavras-chave: Armorican Shelf; Incised valleys; Miocene; Eustasy; Passive margin. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11200/8048.pdf |
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| Satra Le Bris, Catherine; Gautier, Emeric; Bourillet, Jean-francois. |
| Knowledge of the French continental shelf is heterogeneous : the bathymetry of the french EEZ is well known for the deeper domain but insufficient to establish a reference state on the continental shelf. Recopla consists of a modern continental shelf mapping project in cooperation with the oceanographic and hydrographic service of the French Navy. It will contribute to increase the knowledge necessary to establish reference data for the French/European marine strategy. The first task of the Recopla project consisted of an inventory of the geophysical data and metadata available on the French continental shelf, and a classification of these data according the level of processing : raw, processed, interpreted, published. Combining this information with the... |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00071/18234/15792.pdf |
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| Registros recuperados: 45 | |
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