Éditeur(s) : Elsevier
Résumé : In January and February 2002, the presence of certain agricultural pesticides throughout the coastline of the Caribbean island of Martinique was investigated. The tropical climate of the French West Indies is suitable for banana production, which requires intensive use of pesticides. An inventory of all pesticides used on the island (compounds and tonnage) was compiled. Surveys and analyses revealed the presence of pesticides in the plumes of seven rivers. The organochlorine chlordecone and metabolites of aldicarb were detected at nearly all of the monitored sites, even though the use of chlordecone has been prohibited since 1993. Two triazines (ametryn and simazine) were also identified. The concentrations of carbamates and triazines detected in the water and sediment samples from Martinique are comparable to those reported for mainland France. Chlordecone concentrations in the sediment and particulate matter samples were, however, particularly high in the samples from Martinique. Toxicological implications are discussed. Of particular concern are the high levels of chlordecone (which is bioaccumulating and carcinogenic) and further monitoring of this compound is recommended, especially in fish and other sea-food products.
Marine Pollution Bulletin (0025-326X) (Elsevier), 2005-07 , Vol. 51 , N. 5-7 , P. 612-619

Droits : 2005 Elsevier Ltd All rights reserved
http://archimer.ifremer.fr/doc/2005/publication-879.pdf
DOI:10.1016/j.marpolbul.2005.06.026
http://archimer.ifremer.fr/doc/00000/879/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
With only a narrow opening through the Gibraltar and Suez Canals, the Mediterranean Sea is one of thelargest semi-enclosed seas. The marine flora and fauna are some of the richest in the world, relative to itssize, particularly in the coastal habitats, which are also characterized by numerous endemic speciesalthough the introduction of non-indigenous species threatens its rich and unique biodiversity. Followingthe opening of the Suez Canal, and in combination with shipping and aquaculture activities, nonindigenousspecies (NIS) introduction has had measurable impacts on the Mediterranean. Lagoon ecosystemsalong the French coastline, with approx. 100 NIS identified, are considered hot-spot areas forthese species. Rapid assessment sampling for sessile benthic species together with DNA barcoding is arapid, easy and cheap method to detect non-indigenous species. Two nearby and different ecosystemswere sampled for invertebrate species: Saint-Nazaire lagoon, a Special Protection Area within the Natura2000 Network and Canet port, a marina in a small village. The DNA barcoding tool for species identificationwas used for confirming the taxonomy. This showed that, despite the Saint-Nazaire Lagoonclassification within the Natura 2000 network, it is already contaminated with a single NIS that wasfound in high densities and is clearly beginning to dominate the system. It is proposed that a rapidassessment of the sampled environment and the DNA barcode approach are efficient and can providesufficient information on the new target species to be used in conservation planning and ongoingmanagement efforts.
ISSN: 0272-7714

hal-01488926
https://hal-univ-perp.archives-ouvertes.fr/hal-01488926
DOI : 10.1016/j.ecss.2017.02.004

Éditeur(s) : HAL CCSD
Résumé : Report
This activity combines tide gauge and geodetic data to determine the 20th century trends and patterns of relative and absolute sea level changes along the coastline of British Columbia. This information is then used to derive scenarios of relative sea-level rise in coastalcommunities for the 21st century. Particular emphasis is put on the Fraser River Delta and Greater Vancouver region. The projections of 21 st century sea-level rise are provided to provincial and municipal partners to inform local and regional land-use and planning policies.
https://hal.archives-ouvertes.fr/hal-00856631

hal-00856631
https://hal.archives-ouvertes.fr/hal-00856631

Éditeur(s) : HAL CCSD
Résumé : Report
The Canadian coastline is the longest of any country in the world, and is at risk from tsunamis generated in three oceans. The current state of knowledge precludes a complete probabilistic tsunami hazard assessment, which would require quantification of a wide range of possible scenarios for each tsunami source, coupled with modelling that incorporates fine-resolution bathymetry and onland topography to adequately assess potential runup at the coast. This preliminary assessment presents a first attempt to quantify the tsunami hazard on the Canadian Pacific, Atlantic and Arctic coastlines from local and far-field, earthquake and large landslide sources. For each source considered, we calculate the probability that tsunami runup at the coast will exceed 1.5 m (threshold for potential damage) and 3 m (significant damage potential), in a 50-year period. For each coastal region, we then combine the relative hazard from each source to calculate the overall probability that the coastline in question will experience tsunami runup exceeding 1.5 m (and 3 m) within a 50-year period, from any geological source. We also consider the maximum runup levels expected to occur within time periods of 100, 500, 1000, and 2500 years.
https://hal.archives-ouvertes.fr/hal-00856677

hal-00856677
https://hal.archives-ouvertes.fr/hal-00856677
DOI : 10.4095/292067

Éditeur(s) : Neidine Editeurs
Résumé : The present article introduces and defines what are the rogue or freak waves. After an historical reminder on the recent consideration of their existence, several events of waves having struck big or small ships or still the coastline are presented. A paragraph is dedicated to the scientific explanation of the phenomenon and the difference with other phenomenons such tsunamis or tidal bores is clarified. After a reminder of the international mobilization towards a forecast system, a conclusion focuses on events met in New Caledonian waters and analyzes more exactly testimonies related to this type of phenomenon by trying to clarify their causes.
Le présent article introduit et définit ce que sont les vagues scélérates. Après un rappel historique sur la prise en compte récente de leur existence plusieurs cas de figure de vagues ayant frappé grands ou petits navires ou encore la côte sont présentés.Un paragraphe est consacré à l'explication scientifique du phénomène et la différence avec d'autres cas de figure tels les tsunamis ou les mascarets est explicitée. Après un rappel de la mobilisation internationale vers un système de prévision, une conclusion se focalise sur les cas de figure rencontrés dans les eaux calédoniennes et analyse plus précisément deux témoignages de ce type de phénomène en tentant d'en expliciter les causes.
Tai Kona (2269-7535) (Neidine Editeurs), 2014-02 , N. 7 , P. 26-40

Droits : Tai Kona
http://archimer.ifremer.fr/doc/00186/29724/28142.pdf
http://archimer.ifremer.fr/doc/00186/29724/

Éditeur(s) : HAL CCSD Université des Antilles
Résumé : International audience
In this study, we propose to analyze the limits of mass tourism in the French Antilles, specifically the decline of tourism, economic limits, and ecological degradation). The recognition of these limits is overdue, and signals a need to define another model for tourism development.The popular coastal sector in the south of Martinique has been subject new regulations to protect marine resources. These regulations require the development of new practices and a greater level of awareness for tourists, for example, around coral reefs and mangroves. Ecotourism programs aim to demonstrate to visitors the forests rich natural resources and biodiversity in general. It also features the inclusion of small rural businesses that benefit from additional sources of revenue as a result of ecotourism.The situation in the French Antilles is complex: Urbanization is fraught with serious consequences for the coastline. Tourism products currently being marketed on the island are not competitive (particularly against the political dynamics of the neighbouring island of Dominica). Ecotourism and sustainable tourism are just beginning to develop in such destinations, where tourism has been declining in the last ten years. The situation of the French Antilles is paradoxical in a region that generally has a very favourable tourism. Assessing these limits through the scope of ecotourism helps to highlight the causes of these difficulties and to adapting to new tourism practices.
En el contexto de este estudio, nos proponemos analizar los límites del turismo de masas en las Antillas Francesas (depreciación del turismo, las limitaciones económicas, ecológicas y las molestias). Este reconocimiento de esos límites está en el origen de la conciencia tardía de la necesidad de definir otro modelo de desarrollo turístico.En el sector costero de la más popular, como en el sur de Martinica, se pone en la normativa nuevo lugar para proteger los recursos marinos. Esto requiere el desarrollo de nuevas prácticas y la sensibilización de los turistas, por ejemplo, alrededor de los arrecifes de coral y los manglares.Programas en torno al ecoturismo también tienen como objetivo dar al visitante la riqueza de los recursos forestales y la biodiversidad en general. También incluye las pequeñas empresas rurales que reciben los nuevos ingresos a través del turismo.Pero la situación es compleja en las Antillas francesas: la urbanización está llena de importantes consecuencias para la costa. Productos turísticos que se comercializan actualmente no son competitivos (en particular, contra la dinámica política de la cercana isla de Dominica). Ecoturismo y desarrollo sostenible están empezando a desarrollar en este destino turístico, donde el turismo está en problemas en los últimos diez años.Esta situación es bastante paradójico en un turismo regional muy favorable. Sin lugar a dudas, pensando en el ecoturismo contribuye a identificar los destinos de estos retrasos y dificultades para adaptarse a nuevas prácticas de turismo.
Dans le cadre de cette étude, l’accent est mis sur les limites du tourisme de masse dans les Antilles françaises (dépréciation du tourisme, les contraintes économiques et les nuisances écologiques). La reconnaissance de ces limites est à l'origine de la prise de conscience tardive de la nécessité de définir un autre modèle de développement touristique.Dans le sud de la Martinique, le secteur le plus populaire du littoral, de nouvelles règlementations sont mises en place pour protéger les ressources marines. Cela nécessite le développement de nouvelles pratiques et de sensibilisation des touristes notamment autour des récifs coralliens et les mangroves. Les programmes autour de l'écotourisme visent également à montrer aux visiteurs la richesse des ressources forestières et de la biodiversité en général. Il comprend également les petites entreprises rurales qui reçoivent de nouveaux revenus grâce au tourisme.La situation est complexe dans les Antilles françaises: l'urbanisation est lourde de conséquences importantes sur la côte. Les produits touristiques commercialisés actuellement ne sont pas compétitifs (notamment contre la dynamique politique de l'île voisine de la Dominique). L'écotourisme et le tourisme durable commencent tout juste à se développer dans ces destinations où le tourisme classique est en difficulté depuis une dizaine d’années ; situation assez paradoxale au regard du dynamisme de ce secteur d’activité dans la région.
ISSN: 1779-0980

hal-01624756
https://hal.archives-ouvertes.fr/hal-01624756
DOI : 10.4000/etudescaribeennes.5262

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Patterns of connectivity and self-recruitment are recognized as key factors shaping the dynamics of marine populations. Connectivity is also essential for maintaining and restoring natural ecological processes with genetic diversity contributing to the adaptation and persistence of any species in the face of global disturbances. Estimates of connectivity are crucial to inform the design of both marine protected areas (MPAs) and MPA networks. Among several approaches, genetic structure is frequently used as a proxy for patterns of connectivity. Using 8 microsatellite loci, we investigated genetic structure of the two-banded sea bream Diplodus vulgaris, a coastal fish that is both commercially and ecologically important. Adults were sampled in 7 locations (stretches of coastline approximately 8 km long) and juveniles in 14 sites (~100 to 200 m of coastline) along 200 km of the Apulian Adriatic coast (SW Adri-atic Sea), within and outside an MPA (Torre Guaceto MPA, Italy). Our study found similar genetic diversity indices for both the MPA and the surrounding fished areas. An overall lack of genetic structure among samples suggests high gene flow (i.e. connectivity) across a scale of at least 200 km. However, some local genetic divergences found in two locations demonstrate some heterogeneity in processes renewing the population along the Apulian Adriatic coast. Furthermore, two sites appeared genetically divergent, reinforcing our observations within the genetic makeup of adults and confirming heterogeneity in early stage genetics that can come from either different supply populations or from chaotic genetic patchiness occurring under temporal variation in recruitment and in the reproductive success. While the specific role of the MPA is not entirely known in this case, these results confirm the presence of regional processes and the key role of connectivity in maintaining the local population supply.
ISSN: 1932-6203

hal-01442055
https://hal-univ-perp.archives-ouvertes.fr/hal-01442055
https://hal-univ-perp.archives-ouvertes.fr/hal-01442055/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01442055/file/journal.pone.0167441.pdf
DOI : 10.1371/journal.pone.0167441.s009

Éditeur(s) : HAL CCSD Université des Antilles
Résumé : International audience
This study highlights the importance of tourism issues for the tropical islands. The singularity of the spaces is too often overlooked because of the strength of fantasized representations of the tropical island which is seen as a paradise, a place of accomplishment desires unlimited with an easy life, with its sunny shores, between coral reefs and white sandy beaches lined with coconut trees. These intangible wealth are based on real resources, abundant and vulnerable, like the emblematic image of coral reefs. Although the tropical island destinations are not supported the weight of the major touristic regions of the world but their flows should be reconsidered in the light of the characteristics of these territories (small size, load population, shortage of land, limits of resources) that require defining specific indicators. But the advent of mass tourism in these last frontiers, these "Pleasure Periphery" needs to question the sustainability of tourism development strategies.
Cette étude souligne l’importance des enjeux touristiques pour les îles tropicales. La singularité des espaces est trop souvent négligée en raison de la vigueur des représentations fantasmées de l’île tropicale qui est perçue tel un lieu paradisiaque, un lieu d’accomplissement de désirs illimités où s’écoule une vie facile, avec ses rivages ensoleillés, entre récifs coralliens et plages de sable blanc bordées de cocotiers. Ces richesses immatérielles reposent sur des ressources bien réelles, abondantes et vulnérables, à l’image des emblématiques récifs coralliens. Certes les destinations insulaires tropicales ne connaissent pas les niveaux de fréquentation des grandes régions du monde, mais leurs flux doivent être reconsidérés au regard des caractéristiques de ces territoires (faible superficie, charge de population, rareté de la terre, limites des ressources) qui nécessitent la définition d’indications spécifiques. Mais l’avènement d’un tourisme de masse dans ces ultimes frontières, ces « Pleasure Periphery » nécessite de s’interroger sur la viabilité des stratégies de développement mises en œuvre autour du tourisme.
ISSN: 1779-0980

hal-01624747
https://hal.archives-ouvertes.fr/hal-01624747
DOI : 10.4000/etudescaribeennes.852

Éditeur(s) : HAL CCSD American Meteorological Society
Résumé : Global positioning system (GPS) data from a dense network have been used for the analysis of the diurnal cycle of water vapor over Marseille, France, during the second intensive observation period (IOP2; 21–26 June 2001) of the Expérience sur Sites pour Contraindre les Modèles de Pollution Atmosphérique et de Transport d'Emission (ESCOMPTE) field experiment. Both tomographic analyses and integrated water vapor (IWV) contents from GPS have been used, in addition to wind profiler data and surface observations. Tomographic analysis of data from the dense GPS network and radiosondes provided the continuous temporal evolution of the vertical distribution of water vapor over the city of Marseille. The city is located on the shore of the Mediterranean Sea in southeastern France and is often under the influence of sea-breeze effects. Two different layers of breeze circulation are identified: a shallow sea breeze, blowing perpendicular to the local coastline, and a deep sea breeze, induced by the regional temperature gradient between sea and land. The origin of water vapor is shown to be mainly due to the advection of marine moist air by these sea-breeze circulations. However, the diurnal cycle of water vapor over Marseille is strongly influenced by the synoptic situation, which changes during the IOP2 (between a northerly mistral in the early stage of the IOP and an easterly wind at the end). It is shown that vertical profiles from tomographic analyses (combined with wind profiler data) allow for a proper interpretation of the diurnal cycle observed in IWV. Two-dimensional maps of IWV are also shown to complement the description of the horizontal advection of moisture by the different circulation regimes.
ISSN: 1558-8424

hal-00273624
https://hal.archives-ouvertes.fr/hal-00273624
https://hal.archives-ouvertes.fr/hal-00273624/document
https://hal.archives-ouvertes.fr/hal-00273624/file/drJAM_cycle_diurne_GPS_rev1.pdf
DOI : 10.1175/JAM2450.1

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
We analyse P-wave receiver functions across the western Gulf of Aden and southern Red Sea continental margins in Western Yemen to constrain crustal thickness, internal crustal structure and the bulk seismic velocity characteristics in order to address the role of magmatism, faulting and mechanical crustal thinning during continental breakup. We analyse teleseismic data from 21 stations forming the temporary Young Conjugate Margins Laboratory (YOCMAL) network together with GFZ and Yemeni permanent stations. Analysis of computed receiver functions shows that (1) the thickness of unextended crust on the Yemen plateau is ∼35km; (2) this thins to ∼22km in coastal areas and reaches less than 14km on the Red Sea coast, where presence of a high-velocity lower crust is evident. The average Vp/Vs ratio for the western Yemen Plateau is 1.79, increasing to ∼1.92 near the Red Sea coast and decreasing to 1.68 for those stations located on or near the granitic rocks. Thinning of the crust, and by inference extension, occurs over a ∼130-km-wide transition zone from the Red Sea and Gulf of Aden coasts to the edges of the Yemen plateau. Thinning of continental crust is particularly localized in a <30-km-wide zone near the coastline, spatially co-incident with addition of magmatic underplate to the lower crust, above which on the surface we observe the presence of seaward dipping reflectors (SDRs) and thickened Oligo-Miocene syn-rift basaltic flows. Our results strongly suggest the presence of high-velocity mafic intrusions in the lower crust, which are likely either synrift magmatic intrusion into continental lower crust or alternatively depleted upper mantle underplated to the base of the crust during the eruption of the SDRs. Our results also point towards a regional breakup history in which the onset of rifting was synchronous along the western Gulf of Aden and southern Red Sea volcanic margins followed by a second phase of extension along the Red Sea margin.
ISSN: 0956-540X

hal-00825194
https://hal.archives-ouvertes.fr/hal-00825194
https://hal.archives-ouvertes.fr/hal-00825194/document
https://hal.archives-ouvertes.fr/hal-00825194/file/RF_Hakim2012_GJI.pdf
DOI : 10.1093/gji/ggt072

Éditeur(s) : HAL CCSD Université des Antilles
Résumé : International audience
Coastlines and islands are particularly affected by the development of tourism worldwide. Between "desired costal" and "fantasy Islands", these coveted spaces, with both their tangible and intangible dimensions, are opening to tourism. Attracted by the economic opportunities they so desperately need, and more or less aware of their comparative advantages and limitations, they deliver the most vulnerable preserved resources, the most vulnerable, which are the subject of complex relationships and issues.
Les littoraux et les îles sont des espaces particulièrement prisés par le développement du tourisme à travers le monde. Entre « désir de rivages » et « île fantasmée », ces espaces convoités, tant pour leurs dimensions tangibles qu’intangibles, s’ouvrent au tourisme. Séduits par les opportunités économiques dont ils ont tant besoin, plus ou moins conscients de leur avantage comparatif et de leurs limites, ils livrent des ressources préservées, des plus vulnérables, autour desquelles se construisent de complexes relations et enjeux.
ISSN: 1779-0980

Droits : http://creativecommons.org/licenses/by-nc/
hal-01368499
https://hal.univ-antilles.fr/hal-01368499
https://hal.univ-antilles.fr/hal-01368499/document
https://hal.univ-antilles.fr/hal-01368499/file/le-tourisme-dans-les-environnements-littoraux-et-insulaires-permanences-limites-et-perspectives%20%282%29.pdf

Éditeur(s) : Gauthier-Villars
Résumé : Coastal lagoons have formed where marine inlets or embayments have become partly or wholly enclosed by depositional spits and barriers, built up as a sequel to the world-wide Holocene marine transgression. Spits and barriers consist of sediment (sand, shingle) derived from the sea floor or carrier alongshore from river mouth or eroding cliff sources; they have been shaped primarily by wave action, some migrating landward while others have remained in position or prograded seaward. A modern prevalence of erosion on barrier coastlines, recession resulting from net losses of sediment offshore, alongshore, or landward has been deomonstrated. This is the outcome partly of rising sea level and partly of diminishing sediment supply. Often the consequence of man's impacts on coastal environments. Examples are given of changes that have resulted from the cutting of artificial entrances through barriers to the building of barriers across tidal inlets to exclude marine penetration.
Oceanologica Acta, Special issue (0399-1784) (Gauthier-Villars), 1982

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00246/35750/34258.pdf
http://archimer.ifremer.fr/doc/00246/35750/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Les littoraux et les îles sont des espaces particulièrement prisés par le développement du tourisme à travers le monde. Entre « désir de rivages » et « île fantasmée », ces espaces convoités, tant pour leurs dimensions tangibles qu’intangibles, s’ouvrent au tourisme. Séduits par les opportunités économiques dont ils ont tant besoin, plus ou moins conscients de leur avantage comparatif et de leurs limites, ils livrent des ressources préservées, des plus vulnérables, autour desquelles se construisent de relations complexes et enjeux.
Coastlines and islands are particularly affected by the development of tourism worldwide. Between "desired costal" and "fantasy Islands", these coveted spaces, with both their tangible and intangible dimensions, are opening to tourism. Attracted by the economic opportunities they so desperately need, and more or less aware of their comparative advantages and limitations, they deliver the most vulnerable preserved resources, the most vulnerable, which are the subject of complex relationships and issues.
Corse
Hainan
Martinique

Droits : info:eu-repo/semantics/openAccess
http://journals.openedition.org/etudescaribeennes/5774

Éditeur(s) : Publ. CNEXO (France) (Actes Colloq.)(no. 9)
Résumé : The coastline of Western Ireland has an hyperoceanic climate. Its complicated geological structure and the Pleistocene glacial remnants explain its diversity. Cliffs have various altitudes (megafalaises, high cliffs, low cliffs). Lowland shores are rocky, sandy or built of morainic deposits. Transverse coasts have steep forelands and narrow embayments.
Les littoraux de l'Irlande occidentale ont un climat hyperocéanique. Ils doivent leur diversité à une structure géologique complexe et à l'héritage de la glaciation pléistocène. Les falaises ont des altitudes variées (mégafalaises, hautes falaises, basses falaises). Les côtes basses sont rocheuses, sableuses ou façonnées dans des matériaux morainiques. Des littoraux transverses opposent des promontoires élevés à de profondes baies en bouteille.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1979/publication-6016.pdf
http://archimer.ifremer.fr/doc/00000/6016/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cette étude souligne l’importance des enjeux touristiques pour les îles tropicales. La singularité des espaces est trop souvent négligée en raison de la vigueur des représentations fantasmées de l’île tropicale qui est perçue tel un lieu paradisiaque, un lieu d’accomplissement de désirs illimités où s’écoule une vie facile, avec ses rivages ensoleillés, entre récifs coralliens et plages de sable blanc bordées de cocotiers. Ces richesses immatérielles reposent sur des ressources bien réelles, abondantes et vulnérables, à l’image des emblématiques récifs coralliens. Certes les destinations insulaires tropicales ne connaissent pas les niveaux de fréquentation des grandes régions du monde, mais leurs flux doivent être reconsidérés au regard des caractéristiques de ces territoires (faible superficie, charge de population, rareté de la terre, limites des ressources) qui nécessitent la définition d’indications spécifiques. Mais l’avènement d’un tourisme de masse dans ces ultimes frontières, ces « Pleasure Periphery » nécessite de s’interroger sur la viabilité des stratégies de développement mises en œuvre autour du tourisme.
This study highlights the importance of tourism issues for the tropical islands. The singularity of the spaces is too often overlooked because of the strength of fantasized representations of the tropical island which is seen as a paradise, a place of accomplishment desires unlimited with an easy life, with its sunny shores, between coral reefs and white sandy beaches lined with coconut trees. These intangible wealth are based on real resources, abundant and vulnerable, like the emblematic image of coral reefs. Although the tropical island destinations are not supported the weight of the major touristic regions of the world but their flows should be reconsidered in the light of the characteristics of these territories (small size, load population, shortage of land, limits of resources) that require defining specific indicators. But the advent of mass tourism in these last frontiers, these "Pleasure Periphery" needs to question the sustainability of tourism development strategies.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.852
http://journals.openedition.org/etudescaribeennes/852

Éditeur(s) : HAL CCSD
Résumé : Time-series bathymetric data acquired between 1991 and 2011 have been used to evaluate the recent morphological evolution of the Nice upper continental slope (SE France, Ligurian Sea). Small-scale landslides lead to a retrogressive evolution of the continental shelf/upper slope transition but their frequency, size and impact are not well known. Mapping was undertaken to identify the morphology of landslide scarps and the location of the shelfbreak. Map comparisons were performed using ArcGIS “raster calculator”. Sediment remobilization on the upper slope (up to depths of 200 m) is fast and significant; landslide scars with volumes greater than 25,000 m3 can appear with a frequency less than 8 years. Shelfbreak migration toward the coastline can reach rates of 60 m over 7–8 years where the continental shelf is over 200 m wide. Furthermore, this quantitative analysis highlights alternations between periods of strongly erosive events and sedimentation periods. On the upper slope, eroded volumes can be multiplied by 10 during periods of enhanced landslide patterns (1999–2006). Such cycle-like landslide activity raises the issue of the triggering processes. On the Nice continental slope thick poorly consolidated beds rapidly deposited on a steep slope, earthquakes and rainfall leading to fresh water circulation below the shelf were identified as potential triggers. Our 4D bathymetric study suggests that over the last 20 years the greatest impacting factor may be freshwater outflows.
Engineering Geology for Society and Territory - Volume 4

hal-01218436
https://hal.archives-ouvertes.fr/hal-01218436
DOI : 10.1007/978-3-319-08660-6_42

Éditeur(s) : HAL CCSD
Résumé : International audience
Island barriers are common features along the world coastlines. They have a crucial role in protecting inland and rich lagoonal ecosystems. Erosion and sand transfers on these island barriers during extreme events such as tropical storms or typhoons remain poorly investigated. This work focuses on a multi-scales nalysis (season to decade) of the morphodynamics of Wan-Tzu-Liao sand barrier subjected to extreme waves and sea surges. We combine topographic measurements of the emerged beach at seasonal scale between 2011 to 2012 and long-term (1993-2009) shoreline changes using aerial photographs and satellite images. At the seasonal scale, during Monsoon, the sand was taken from the beach-front and transported seaward outside the study area. During typhoons season, 12 typhoons drove a beach recovery process resulting in a seaward shoreline shift. This annual behavior is discussed in term of roll-over process of the barrier. At the decadal scale, the shoreline changes evidence cross-shore processes in the north part of the barrier and longshore processes in the south. Although the chronic landward migration displays several stages, the strong losses of the barrier area occurs only since 2004 and call into question the general concept of conservation of mass during the roll-over of a barrier.
Revue Paralia, XIIIème Journées Nationales Génie CIvil Génie Côtier
Dunkerque, France

hal-01018203
https://hal.archives-ouvertes.fr/hal-01018203

Éditeur(s) : HAL CCSD Société géologique de France
Résumé : New-Caledonia island consists of an ultramafic nappe thrusted over a continental and arc-derived basement as the result of the closure of a back-arc basin during the upper Eocene. The morphology of New-Caledonia is mostly characterized by its elongated shape and rectilinear coastline. Indeed, the western and eastern edges of the island are delineated by N140 trending normal faults that are well imaged on seismic lines. Major tectonic lineaments onland, including the scarps corresponding to the main boundary of the ultramafic nappe, also trend N140 suggesting a morphotectonic control by faults having similar kinematics (longitudinal flexure-fault of previous authors). We provide detailed observations from some of these scarps demonstrating indeed that these are not erosional features in origin. We explore the possibility that such surfaces do represent major tectonic limits that accommodated extension and significant tectonic thinning of both the peridotite nappe and its basement. Remnants of a complex extensional fault zone, 200 m wide, are still preserved along the western scarp of the Mont Dore mountain, close to Noumea city. The deformed zone is composed of an early shallow dipping detachment fault, some decimeters thick, offset by a group of late high angle normal faults and is bounded by cataclastic breccias that progressively pass into the fractured host peridotite. The late high angle fault zones have been the site of important syn-tectonic fluid circulation and are underlined by cm-thick silica infills bearing vertical striae. Typical morphology of the main scarps with break of slope is related to the combination of high angle normal faults and low angle detachment. Similar shallow dipping detachment surfaces have been observed along the east coast of southern New-Caledonia as well as within the ultramafic nappe itself and its basement. This study confirms that N140 oriented, large fault zones, with pure-normal to transtensional component of displacement, controlled the morphotectonic evolution of New-Caledonia at the regional scale, after the obduction of ophiolite nappe at the end of the Eocene. Such a fact has to be taken into account when attempting to reconstruct the post-obduction evolution of the island and more particularly when considering the development and distribution of the Ni-rich lateritic surfaces.
EISSN: 1777-5817

hal-00411855
https://hal.archives-ouvertes.fr/hal-00411855
DOI : 10.2113/gssgfbull.179.3.315

Éditeur(s) : HAL CCSD Springer International Publishing
Résumé : International audience
Understanding the formation processes of maritime archaeological sites and the maritime landscape in the French West Indies is a new challenge in underwater archaeology. This chapter presents an analysis of formation and conservation processes of maritime archaeological sites in Guadeloupe using evidence from both historical and archaeological research. Formation parameters include contemporary events associated with maritime loss and the in situ geophysical regime. Questions considered include: what natural and/or anthropogenic parameters best classify maritime sites in the context of the French West Indies landscape? And: how do these parameters vary by site location? Field-tested case studies are used to assess the archaeological potential for submerged shipwreck sites for three locational typologies within the landscape: submerged, coastal, and micro-island. Geomorphic parameters, including erosion, sea level evolution, and tectonic activity, are evaluated with regard to the formation of coastal Amerindian and colonial sites. The location of shipwrecks are primarily determined by historic patterns in commercial trade and by topographical constraints associated with accessibility, risk, and the presence of natural harbors, parameters important in the Caribbean. A unique feature of Guadeloupe is the high variability of the structure of the coastline through time. The recent discovery of numerous underwater prehistoric artifacts confirms that several islands, coastal areas, and their archaeological sites have been completely submerged or eroded since their formation. The characterization of these formation processes provides both academically interesting and practical information valuable in assessing the impact of development and urbanization in Guadeloupe’s maritime landscape.
Formation Processes of Maritime Archaeological Landscapes

hal-01448703
https://hal.archives-ouvertes.fr/hal-01448703

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Time-series bathymetric data acquired from 1967 to 2011 are used to evaluate the morphological evolution of the continental shelf and upper continental slope off the city of Nice (SE France, Ligurian Sea). Mapping in water depths of 0–300 m was undertaken to identify the changing morphology of landslide scars and their erosive chutes. Quantitative Digital Terrain Model (DTM) comparisons reveal areas of erosion and deposition over intervals of 5–8 years. Sediment remobilization events on the upper slope (above depths of 200 m) are frequent and significant; landslide scars with volumes > 25,000 m3 can occur with frequencies of < 8 years. Shelf break retreat toward the coastline can reach 60 m over 7–8 years where the continental shelf is wider (> 200 m). Periods of quiescence (1980–1990 and 2006–2011) are seen to alternate with periods when rapid retrogressive failure increase sediment volumes eroded from the upper slope-shelf transition by an order of magnitude (1999–2006). Temporal variations in landslide activity were correlated to several potential triggering factors that individually would not induce failures, including earthquake activity, rapid deposition of fine-grained sediments on a steep slope, and rainfall leading to fresh groundwater circulation below the shelf. This 4D bathymetric study suggests that over the last 50 years the most important factor triggering landslides offshore Nice is overpressure due to freshwater outflows.
ISSN: 0025-3227

hal-01346866
https://hal.archives-ouvertes.fr/hal-01346866
DOI : 10.1016/j.margeo.2016.06.009