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| Registros recuperados: 172 | |
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| Arnaud, Fabien; Revillon, Sidonie; Debret, Maxime; Revel, Marie; Chapron, Emmanuel; Jacob, Jeremy; Giguet-covex, Charline; Poulenard, Jerome; Magny, Michel. |
| Two well-dated ca Holocene-long sedimentary sequences from deepest parts of Lake Bourget provide new insights onto the evolution of erosion patterns at a regional scale in NW European Alps. The combination of high resolution geochemistry - XRF core scanning, calibrated by 150 punctual measurements - and isotope geochemistry (epsilon Nd) of the terrigenous fraction permitted the reconstruction not only of the intensity, but also the type (physical erosion vs. chemical weathering) and the location (Prealpine massifs vs. High Crystalline massifs) of dominant erosion processes. Those data point the persistency of weak erosion fluxes from 9600 to 5500 cal. BP due both to a dry climate and the growing sheltering effect of soils that rapidly progressed between... |
| Tipo: Text |
Palavras-chave: Holocene; Alps; Erosion; Soil dynamics; Paleohydrology. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00106/21723/20064.pdf |
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| Suanez, Serge; Blaise, Emmanuel; Cancouet, Romain; Floc'H, France. |
| An experimental study based on field measurements for runup parameterization was conducted on a high energy macrotidal beach located on North Brittany (Vougot Beach). The approach was based on morphological and hydrodynamic high frequency monitoring collected between 2008 and 2013. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes (1971) runup formula. In addition, an empirical equation based on observed tidal water level and offshore wave height was produced to estimate extreme water levels defined as the sum of (i) astronomic tide, (ii) storm surge, and (iii) vertical wave runup. A good correlation between this empirical equation (1.01H(mo)xi(o)) and field runup measurements... |
| Tipo: Text |
Palavras-chave: Macrotidal beach; Runup; Storm; Dune; Erosion; Extreme water level. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00639/75097/75610.pdf |
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| Suc, Jean-pierre; Gillet, Herve; Cagatay, M. Namik; Popescu, Speranta-maria; Lericolais, Gilles; Armijo, Rolando; Melinte-dobrinescu, Mihaela Carmen; Sen, Sevket; Clauzon, Georges; Sakinc, Mehmet; Zabci, Cengiz; Ucarkus, Gulsen; Meyer, Bertrand; Cakir, Ziyadin; Karakas, Cagil; Jouannic, Gwenael; Macalet, Rodica. |
| The two sides of the Strandja Sill show a highly discontinuous stratigraphic succession since the Late Oligocene. This area, together with the Sea of Marmara Basin, is usually proposed as the gateway for the Paratethyan freshwaters and organisms that constituted the Lago Mare facies in the Mediterranean Sea during the Messinian Salinity Crisis (MSC). Our investigations involving new field observations and datings, together with previous studies, suggest that the sill has possibly experienced such a connection at around 8 Ma, i.e. significantly before the crisis. The proposal of a sea-level drop of the Black Sea before 7 Ma is not supported by our data on dinoflagellate cysts. Consistency of calcareous nannofossil succession at DSDP Site 380 is reinforced,... |
| Tipo: Text |
Palavras-chave: Mediterranean-Paratethys connection; Onshore-offshore stratigraphy; Messinian Salinity Crisis; Erosion; Fluvial network. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00251/36217/34768.pdf |
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| Blaise, Emmanuel; Suanez, Serge; Stephan, Pierre; Fichaut, Bernard; David, Laurence; Cuq, Veronique; Autret, Ronan; Houron, Julien; Rouan, Mathias; Floc'H, France; Ardhuin, Fabrice; Cancouet, Romain; Davidson, Robert; Costa, Stephane; Delacourt, Christophe. |
| Between December 2013 and March 2014, a cluster of about 12 storm events hit the coast of Brittany with an exceptional frequency. It was in February that these storm events were the most frequent and particularly virulent. The significant wave heights measured off Finistere reached respectively 12.3 m and 12.4 m during Petra and Ulla storms on February 5 and 14. However, analysis of hydrodynamic conditions shows that only three episodes promoted extreme morphogenetic conditions because they were combined with high spring tide level. The first one occurred on January 1 to 4, it was followed by events from February 1 to 3, and March 2-3. During these three extreme events observed tide levels were above highest astronomical tide level (HAT). Maximum surge... |
| Tipo: Text |
Palavras-chave: Tempête; Érosion; Trait de côte; Marée de vive-eau; Bretagne; Surcote; Storm; High spring tide; Surge; Erosion; Shoreline; Brittany. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00310/42171/43029.pdf |
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| Bache, Francois; Olivet, Jean-louis; Gorini, Christian; Rabineau, Marina; Baztan, Juan; Aslanian, Daniel; Suc, Jean-pierre. |
| Though the late Miocene "Messinian Salinity Crisis" has been intensely researched along the circum-Mediterranean basins, few studies have focused on the central part of the Mediterranean Basin and, especially, the pre-salt deposits. To improve our knowledge of the Messinian events, it is imperative to better understand this domain. In this study, we provide a more complete understanding of this central domain in the Provence Basin. We were able to recognize: a) thick marine detrital series (up to 1000 m) derived from the Messinian subaerial erosion which is partly prolongated in the distal part by b) a thick unit of deep marine deposits (up to 800 m) prior to the evaporites; c) a thick presumed alternation of detritals and evaporites (1500 m) below the... |
| Tipo: Text |
Palavras-chave: Erosion; Detrital deposits; Miocene; Provence Basin; Mediterranean; Gulf of Lions; Salinity Crisis; Messinian. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6870.pdf |
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| Suanez, Serge; Cancouet, Romain; Floc'H, France; Blaise, Emmanuel; Ardhuin, Fabrice; Filipot, Jean-francois; Cariolet, Jean-marie; Delacourt, Christophe. |
| Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France) over the past decade (2004–2014) has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i) astronomic tide; (ii) storm surge; and (iii) vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL) data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed... |
| Tipo: Text |
Palavras-chave: Macrotidal beach; Runup; Storm; Dune; Erosion; Extreme water level; NAO. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38765/37306.pdf |
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| Jacobs, Walter; Le Hir, Pierre; Van Kesteren, Walther; Cann, Philippe. |
| Results of a large number of erosion tests on artificially generated and relatively dense sand-mud mixtures are presented. Soil sample compositions are varied concerning clay-silt and sand-silt ratio, and clay mineralogy. The experimental set-up consists of a re-circulating small-scale rectangular erosion flume with unidirectional flow conditions. The erosion threshold and erosion rate are studied through step by step increasing the flow rate during a test. Results clearly indicate time-decreasing erosion during which individual flocs are randomly eroded, and time-independent (steady) erosion during which both sand and mud particles are continuously and uniformly eroded. These two erosion types appear to be floc and surface erosion, respectively... |
| Tipo: Text |
Palavras-chave: Erosion; Sand-mud mixtures; Clay; Sediment structure; Critical shear stress; Strength. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15252/12678.pdf |
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| Miramontes Garcia, Elda; Garreau, Pierre; Caillaud, Matthieu; Jouet, Gwenael; Pellen, Romain; Hernández-molina, F. Javier; Clare, Michael A.; Cattaneo, Antonio. |
| Contourites are common morphological features along continental margins where currents encounter the seafloor. They can provide long-term archives of palaeoceanography, may be prone to sediment instability, and can have a great potential for hydrocarbon exploration. Despite their importance and increasingly recognised ubiquitous occurrence worldwide, the link between oceanographic processes and contourite features is poorly constrained. In particular, it is unclear under which specific conditions sediments are mobilised, modified and deposited by bottom currents. Here, we aim to determine key bottom current characteristics (velocity and bottom shear stress) affecting contourite deposition, by assuming that recent oceanographic regimes may be extended back... |
| Tipo: Text |
Palavras-chave: Sediment drift; Erosion; Oceanic circulation; Bottom shear stress. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59426/62241.pdf |
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| Meur-ferec, Catherine; Le Berre, Iwan; Cocquempot, Lucie; Guillou, Elisabeth; Henaff, Alain; Lami, Thibaut; Le Dantec, Nicolas; Letortu, Pauline; Philippe, Manuelle; Nous, Camille. |
| Coastal development, combined with the intrinsic mobility of coasts and the context of climate change, tends to increase the vulnerability of coastal territories. This article proposes, on one hand, a renewed interdisciplinary approach to the concept of vulnerability allowing to overcome the nature/society dichotomy. On the other hand, the paper presents an inter-sectoral researchers-managers approach to build a series of indicators to monitor the four components of systemic vulnerability (hazards, stakes, management and representations). These indicators lay the ground for an integrated observatory, source of data for research as well as to inform decisions regarding the adaptation of coastal territories. |
| Tipo: Text |
Palavras-chave: Coastal risks; Erosion; Sea-flooding; Vulnerability; Interdisciplinary; Intersectorality; Indicators; Adaptation; Observatory. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74122/73559.pdf |
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| Didier, David; Bernatchez, Pascal; Augereau, Emmanuel; Caulet, Charles; Dumont, Dany; Bismuth, Eliott; Cormier, Louis; Floc'H, France; Delacourt, Christophe. |
| Increasingly used shore-based video stations enable a high spatiotemporal frequency analysis of shoreline migration. Shoreline detection techniques combined with hydrodynamic conditions enable the creation of digital elevation models (DEMs). However, shoreline elevations are often estimated based on nearshore process empirical equations leading to uncertainties in video-based topography. To achieve high DEM correspondence between both techniques, we assessed video-derived DEMs against LiDAR surveys during low energy conditions. A newly installed video system on a tidal flat in the St. Lawrence Estuary, Atlantic Canada, served as a test case. Shorelines were automatically detected from time-averaged (TIMEX) images using color ratios in low energy conditions... |
| Tipo: Text |
Palavras-chave: Video monitoring; Shoreline detection; Beach morphology; Mobile terrestrial LiDAR; Erosion; Atlantic Canada. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00638/75022/75656.pdf |
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| Raillard, Olivier. |
| Cette étude a pour but d'introduire dans le modèle de production globale du bassin de Marennes-Oléron une nouvelle source de variabilité des teneurs de la colonne d'eau en éléments particulaires par la prise en compte des échanges verticaux à l'interface eau-sédiment. Dans la précédente formulation du modèle les biodépots, alors la seule source d'alimentation du fond, sont instantanément remis en suspension. Toutefois la faible bathymétrie ainsi que des régimes de courants et de vents variables déterminent des variations importantes dans les concentrations du matériel particulaire (Bacher, 1989) susceptibles d'influer sur la production biologique primaire et secondaire (fig. 1). Ces échanges conditionnent en partie les fluctuations de quantité de lumière... |
| Tipo: Text |
Palavras-chave: Courantologie; Modélisation; Erosion; Sédimentation; Marennes Oléron; Département Charente-Maritime. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00146/25741/23844.pdf |
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| Registros recuperados: 172 | |
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