Éditeur(s) : Styli 2003. Trente ans de crevetticulture en Nouvelle-Calédonie. Nouméa - Koné, 2-6 juin 2003. 2004. Gorarant C, Harache Y, Herbland A, Mugnier C. Ed. Ifremer, Actes de Colloque, n°38, pp.113-120
Résumé : Two oyster species are currently present along the French coasts : the indigenous European flat oyster (Ostrea edulis), and the Pacific cupped oyster (Crassostrea gigas), that has been introduced from Japan since the beginning of the 70ies. The flat oyster successively suffered from two protozoan diseases during the 60ies and its production decreased from 20 000 tons/year by that time to 1 500 tons/year nowadays. Consequently, the oyster production is principally (99%) based upon the Pacific oyster species with approximately 150 000 tons/year among which 90% are grown from the natural spat. However, the hatchery production of this species is developing and was estimated to 400 to 800 millions spat in 2002. Moreover, strengthened relationships between IFREMER and the 5 commercial hatcheries, that all joined the SYSAAF (Union of the French poultry, shellfish and fish farming selectors), allow to plan for new genetic breeding programs. At the end of the 80ies, IFREMER initiated a genetic breeding program for the resistance of the European flat oyster to the bonamiosis, and obtained strains more tolerant to this disease. After two generations of massal selection, molecular markers had identified a reduced genetic basis in this program. It was then reoriented to an intra-familial selection. However, we were confronted to a zootechnic problem to manage such a scheme and we compromised by an intra-cohorts of families selection scheme managed using molecular markers. The program has now reached the transfer level with experimentation at a professional scale. Concerning the Pacific cupped oyster, and in parallel with the obtaining and the study of polyploids, performance of different Asian cupped oyster strains were compared to the one introduced in France thirty years ago and currently suffering from summer mortalities. The local strain exhibited better performance, certainly based upon a good local adaptation. In other respects, although early growth is a relevant criteria for selection for growth to commercial stage, it is not to be privileged in the context of an oyster producing region with a limited food availability. Contrary, the spat summer mortality became a priority for numerous teams (genetic, physiology, pathology, ecology,...) joined in the MOREST program. The first results showed important survival differences between fullsib and halsib families. They indicate a genetic determinism to this character "survival" and promote for its selection.
Deux espèces d'huîtres sont aujourd'hui présentes sur les côtes françaises : l'huître plate européenne (Ostrea edulis), indigène, et l'huître creuse du Pacifique (Crassostrea gigas), introduite du Japon dans le début des années 1970. L'huître plate a subi coup sur coup, dans les années 1960, deux maladies dues à des protozoaires parasites et sa production est ainsi passée de 20 000 t/an dans les années 1960 à 1500 t/an aujourd'hui en France. Il en résulte que la filière ostréicole française repose quasiment exclusivement (99%) sur la production de l'huître creuse, C. gigas, avec 150 000 tonnes en 2000 dont environ 90% est issu du captage naturel. Cependant, la reproduction de cette espèce en écloserie est actuellement en expansion avec une estimation de 400 à 800 millions de naissains commercialisés en 2002. Des rapports renforcés entre l'IFREMER et les cinq écloseries françaises de la filière ostréicole, qui adhèrent toutes au SYSAAF (SYndicat des Sélectionneurs Avicoles et Aquacoles Français), permettent désormais d'envisager le développement de nouveaux programmes d'amélioration génétique. A la fin des années 1980, un programme de sélection pour la résistance de l'huître plate à la bonamiose a été initié au sein de l'IFREMER, et a permis d'obtenir des souches plus tolérantes à cette maladie. Après deux générations en sélection massale, les marqueurs moléculaires avaient mis en évidence une base génétique réduite au sein de ce programme qui s'était alors orienté vers une sélection intra-familiale. Devant la lourdeur zootechnique d'un tel schéma, un compromis a été trouvé en réalisant une sélection au sein de cohortes de familles biparentales, la gestion de ces cohortes étant permise par les analyses moléculaires. Le programme est maintenant dans sa phase de transfert, avec des expérimentations à plus grande échelle en partenariat avec la profession. En ce qui concerne l'huître creuse, et en parallèle de l'obtention et l'étude de polyploïdes, les performances de différentes souches d'huîtres creuses provenant d'Asie ont été comparées à celles de la souche introduite en France il y a trente ans, sujette à des mortalités estivales. La souche locale présente de meilleures performances, vraisemblablement grâce à une adaptation bien réalisée. Par ailleurs, bien que l'amélioration de la croissance jusqu'à la taille commerciale s'avère possible par une sélection précoce au stade larvaire, le critère de croissance n'est pas nécessairement à privilégier dans le contexte d'un bassin ostréicole disposant de ressources trophiques limitées. En revanche, les importantes mortalités rencontrées par le naissain en périodes estivales constituent le sujet d'étude prioritaire sur lequel se sont penchées de nombreuses équipes (génétique, physiologie, pathologie, écologie, ...) dans le cadre du grand défi MOREST. Les premiers résultats ont mis en évidence de fortes différences de survie entre des familles biparentales d'animaux indiquant un déterminisme génétique du caractère « survie », et encourageant dans la voie d'une sélection pour ce caractère.

Droits : 2004 Ifremer
http://archimer.ifremer.fr/doc/2003/acte-3491.pdf
http://archimer.ifremer.fr/doc/00000/3491/

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Large-scale periodic undulations within the oceanic and continental lithospheres revealed by a number of observations, are often treated as compressive instabilities, i.e. lithospheric buckling or folding. These undulations are normally associated with intensive faulting, which raises questions on the role of faulting in the folding process, and even on the possibility of folding in highly faulted media. In this study, we demonstrate that folding can "survive" faulting and that both processes may develop concurrently, so that faulting may serve as a mechanism of folding in the brittle domain. We support this hypothesis by direct numerical modeling. The results are compared with the data on three most prominent and well-known cases of the oceanic and continental folding-like deformation ("Indian Ocean" type, "Western Gobi (central Asia)" type and "Central Australian" type). We demonstrate that under reasonable tectonic stresses, folds can develop from faults cutting through the brittle parts of the lithosphere. The predicted wavelengths and nite growth rates are in agreement with the observations. We also show that within a continental lithosphere with thermotectonic age greater than 400 My, either a bi-harmonic mode (two superimposed wavelengths, crustal and mantle one) or a coupled mode (mono-layer deformation) of inelastic folding can develop, depending on the strength and thickness of the lower crust.
ISSN: 0094-8276

ird-00388016
http://hal.ird.fr/ird-00388016
http://hal.ird.fr/ird-00388016/document
http://hal.ird.fr/ird-00388016/file/fig3.pdf
http://hal.ird.fr/ird-00388016/file/fig1.pdf

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Seismic reflection profiles from the sediment rich Alaska subduction zone image short, frontally accreted, imbricate thrust slices and repeated sequences of long, underthrust sheets. Rapid landward increases in wedge thickness, backthrusting, and uplift of the forearc are observed, suggesting underthrusting beneath the wedge. These features and a widely varying frontal wedge morphology are interpreted to be caused by different modes of accretion active concurrently along the trench at different locations. Episodic wedge growth is observed in high basal friction experiments using sand as an analog material. Two phases of an accretionary cycle can be distinguished: frontal accretion of short imbricate thrust slices, alternating with underthrusting of long, undeformed sheets. The phase is shown experimentally to depend upon the surface slope of the wedge. Mechanical analysis of the forces at work predicts these two modes of deformation due to the varying frictional forces and yield strengths for a temporally varying wedge geometry. Maximum length of thrust slices is calculated for experimental conditions and confirmed by the observations. For a steep frontal slope (at the upper limit of the Mohr-Coulomb taper stability field) the overburden is too great to permit underthrusting, and failure occurs repeatedly at the wedge front producing short imbricate slices. The wedge grows forward, lowering the surface angle to the minimum critical taper. For a shallow frontal slope the reduced overburden along an active roof thrust permits sustained underthrusting, causing frontal erosion and backthrusting, steepening the wedge and thus completing the cycle.
ISSN: 0148-0227

hal-01261538
https://hal.archives-ouvertes.fr/hal-01261538
https://hal.archives-ouvertes.fr/hal-01261538/document
https://hal.archives-ouvertes.fr/hal-01261538/file/gutscherJGR1998.pdf

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : The term social entrepreneurship is not new but during the past decade its interests have increased rapidly around the world while its field is still young and fragmented (Gawell, 2013). We believe that in one way or the other, the main objective of social entrepreneurship is to solve social, economic and environmental problems for sustainable development goals. One of the development challenges is the fact that Haiti has 0.47 as Human Development Index (HDI) figuring 168th among 187 countries with 58.6 % of the population living under the poverty line and 24.6% under the extreme poverty line with less than 1$UD per day (PNUD & MCI, 2014). Despite the fact that Haiti has a unique know-how that is passed down for generations in the area of craft, small industry and in the processing of products, social entrepreneurship has not taken its roots as it should have. Importantly, to get where they are today, it is undeniable that developed nations leaned the strengths of their development on human capital to produce physical/material capital. Most often, the human capital is utilized to produce strong public policies which enable the economic growth. The value of using human capital as a pillar for economic growth proved itself for Asian nations with an annual economic growth of 6.9% between 1980 and 1990 against 1.5% for Latin America (Gener, 2005). Thus, in this paper, we looked at the Emergence of Social Entrepreneurship for economic growth in Haiti.
 L'entrepreneuriat social n'est pas nouveau, mais au cours de la dernière décennie, l’intérêt pour ce terme a rapidement augmenté dans le monde alors que son champ est encore jeune et fragmenté (Gawell, 2013). Nous pensons que d'une manière ou d'une autre, l'objectif principal de l'entrepreneuriat social est de résoudre les problèmes sociaux, économiques et environnementaux en vue d'atteindre les objectifs de développement durable. La mission ou les activités d'une organisation sont soit entièrement philanthropiques soit uniquement commerciales. L'un des défis du développement est le fait que l’indice de développement humain (IDH) d’Haïti est de 0,47, le pays figure au 168e (parmi 187 pays). 58,6% de la population vit sous le seuil de pauvreté et 24,6% sous le seuil de pauvreté extrême avec moins de 1 USD par jour (PNUD et MCI, 2014). Malgré le fait qu’Haïti possède un savoir-faire unique transmis depuis des générations dans le domaine de l'artisanat, de la petite industrie et de la transformation des produits, l'entrepreneuriat social n'a pas pris ses racines comme il se doit. Il est important de noter que pour arriver là où ils sont aujourd'hui, il est indéniable que les pays développés ont soutenu le développement du capital humain pour produire du capital physique / matériel. Le plus souvent, le capital humain est utilisé pour produire des politiques publiques solides qui permettent la croissance économique. La valeur de l'utilisation du capital humain comme pilier de la croissance économique a été prouvée pour les pays asiatiques avec une croissance économique annuelle de 6,9% entre 1980 et 1990 contre 1,5% pour l'Amérique latine (Gener, 2005). Ainsi, dans cet article, nous examinons l'émergence de l'entrepreneuriat social pour la croissance économique en Haïti.
Haïti

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.10406
http://journals.openedition.org/etudescaribeennes/10406

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
The nucleation, propagation, and associated folding of ramp-flat-ramp normal faults were analyzed from field examples developed in a brittle/ductile multilayer sequence of the Huércal-Overa Basin (SE Spain). Gently dipping sandy silt layers, which display a low cohesive strength (C0 = 7 kPa, μ = 34°), favor the development of extensional detachments. A tectonic origin instead of a possible gravitational origin is supported by the perpendicularity between the paleoslope direction of the fluvial-deltaic environment inferred from imbricated pebbles, and the senses of movement deduced from fault slicken-lines. The link between high-angle normal faults (HANFs) --formed at different levels in the layered sequence-- with horizontal fault segments comes to develop ramp-flat-ramp normal faults with associated roll-over in the hanging wall. Observed extensional duplexes are formed by parallel detachments connected through synthetic Riedel faults. These Riedel faults would produce the back-rotation of the individual blocks (horses), i.e., extensional folding of the originally subhorizontal layers. There is no correlation between the analyzed ramp-flat-ramp normal faults, accommodating south-southeastward extension during Serravallian-lower Tortonian, and either the regional Alpujarride/Nevado-Filabride west-directed extensional shear zone or the top-to-the-north detachments within Alpujarride units, which are clearly sealed by Serravallian-lower Tortonian sediments. Therefore, the studied normal faults are restricted to the brittle/ductile multilayer fluvio/deltaic sequence and accommodate moderate late extension instead of belonging to a large crustal extensional system connected with a regional detachment at depth. Therefore, the basin formed in a moderate crustal thickness context where small and medium-scale extensional systems were subordinate structures. These natural examples support the development of low-angle normal faults at very shallow crustal levels in multilayer sequences with suitable rheological conditions.
ISSN: 0278-7407

hal-00750352
https://hal.archives-ouvertes.fr/hal-00750352
DOI : 10.1029/2012TC003130

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Long-term exposure to air pollution (AP) has been shown to have an impact on mortality in numerous countries, but since 2005 no data exists for France. We analyzed the association between long-term exposure to air pollution and mortality at the individual level in a large French cohort followed from 1989 to 2013. The study sample consisted of 20,327 adults working at the French national electricity and gas company EDF-GDF. Annual exposure to PM10, PM10–2.5, PM2.5, NO2, O3, SO2, and benzene was assessed for the place of residence of participants using a chemistry-transport model and taking residential history into account. Hazard ratios were estimated using a Cox proportional-hazards regression model, adjusted for selected individual and contextual risk factors. Hazard ratios were computed for an interquartile range (IQR) increase in air pollutant concentrations. The cohort recorded 1967 non-accidental deaths. Long-term exposures to baseline PM2.5, PM10-25, NO2 and benzene were associated with an increase in non-accidental mortality (Hazard Ratio, HR = 1.09; 95% CI: 0.99, 1.20 per 5.9 μg/m3, PM10-25; HR = 1.09; 95% CI: 1.04, 1.15 per 2.2 μg/m3, NO2: HR = 1.14; 95% CI: 0.99, 1.31 per 19.3 μg/m3 and benzene: HR = 1.10; 95% CI: 1.00, 1.22 per 1.7 μg/m3).The strongest association was found for PM10: HR = 1.14; 95% CI: 1.05, 1.25 per 7.8 μg/m3. PM10, PM10-25 and SO2 were associated with non-accidental mortality when using time varying exposure. No significant associations were observed between air pollution and cardiovascular and respiratory mortality. Long-term exposure to fine particles, nitrogen dioxide, sulfur dioxide and benzene is associated with an increased risk of non-accidental mortality in France. Our results strengthen existing evidence that outdoor air pollution is a significant environmental risk factor for mortality. Due to the limited sample size and the nature of our study (occupational), further investigations are needed in France with a larger representative population sample.
ISSN: 0160-4120

hal-01187145
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187145
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187145/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187145/file/Association%20between%20long-term%20exposure%20to%20air%20pollution%20and%20mortality_accepted.pdf
DOI : 10.1016/j.envint.2015.08.006

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We have performed tri-axial compression experiments on olivine aggregates at 900 °C and at a confining pressure of 300 MPa in a high-resolution gas-medium mechanical testing apparatus. Deformation at two different constant strain rates (1.1 × 10− 5 s− 1 and 3.4 × 10− 4 s− 1) yields continuous hardening, reaching maximal differential stresses of 930 and 1076 MPa, respectively, before sample failure at ca. 10% strain. The deformed samples were characterized by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Crystallographic preferred orientations (CPO) are weak but reveal an alignment of the [010] axes around the compression direction and some concentration of [001] and [100] axes normal to it. TEM observations confirm plastic deformation by dislocation glide, with both [001] and [100] Burgers vectors. Electron tomography, performed for the first time on deformed fined-grained olivine, shows that [001] dislocations glide extensively on {110} and {130} planes, in complement to the (010) and (100) glide planes often reported at high temperatures. [100] dislocations glide mostly on (010), but {011} and {041} planes are also activated. The experimental CPO and relative activity of slip systems are well reproduced by viscoplastic self-consistent simulations in which all [100] and [001] slip systems have similar strengths. They are also consistent with olivine CPO from natural samples deformed at low temperature. Comparison of the present mechanical results to those obtained for olivine single-crystals at similar conditions shows that at low temperature (below 1100 °C) and high stress (> 300 MPa) polycrystalline olivine has a more complex mechanical behavior than single crystals. However, both datasets advocate for a much weaker dry mantle lithosphere than previously thought.
ISSN: 0040-1951

hal-01053513
https://hal.archives-ouvertes.fr/hal-01053513
DOI : 10.1016/j.tecto.2014.03.022

Éditeur(s) : HAL CCSD De Gruyter
Résumé : International audience
This study aims at better understanding the respective influences of specific gravity (γ), microfibril angle (MFA), and cell-wall matrix polymers on viscoelastic vibrational properties of wood in axial direction. The wide variations of properties between normal wood (NW) and compression wood (CW) are in focus. Three young bent trees (Picea abies, Pinus sylvestris and Pinus pinaster) that recovered verticality were sampled. Several observed differences between NW and CW were highly significant in terms of anatomical, physical (γ, shrinkage, CIELab colorimetry), mechanical (compressive strength), and vibrational properties. Specific dynamic modulus of elasticity (E'/γ) decreases with increasing MFA, and Young's modulus (E') can be satisfactorily explained by γ and MFA. Apparently, the type of the cell wall polymer matrix is not influential in this regard. The damping coefficient (tanδ) does not depend solely on MFA of NW and CW. The tanδ - E'/γ relationship evidences that, at equivalent E'/γ, the tanδ of CW is approx. 34% lower than that of NW. This observation is ascribed to the more condensed nature of CW lignins, and this is discussed in the context of previous findings in other hygrothermal and time/frequency domains. It is proposed that the lignin structure and the amount and type of extractives, which are both different in various species, are partly responsible for taxonomy-related damping characteristics.
ISSN: 0018-3830

hal-00808062
https://hal.archives-ouvertes.fr/hal-00808062
https://hal.archives-ouvertes.fr/hal-00808062/document
https://hal.archives-ouvertes.fr/hal-00808062/file/Changes_viscoelastic_vibrational_Bremaud_al.pdf
DOI : 10.1515/hf-2011-0186

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.
ISSN: 1553-7366

hal-01546176
https://hal.archives-ouvertes.fr/hal-01546176
DOI : 10.1371/journal.ppat.1002742

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Mid-ocean ridge basalt (MORB) is the most abundant magma on Earth, and provides a geochemical window into the mantle. Deriving mantle composition and melting processes from the erupted lavas requires correction to be made for their evolution as they pass through and generate the oceanic crust. This is typically done by assuming that modification of melts in crustal magma chambers occurs exclusively by fractional crystallisation. However, extensive mineral major- and trace element data from a full section of fast-spread lower crustal rocks exposed in Hess Deep (equatorial Pacific Ocean) demonstrate that their evolution is instead controlled by reactive porous flow. These reactions lead to a strong enrichment in, and fractionation of, incompatible trace elements in the melt (as recorded by clinopyroxene compositions), leading to melt compositions far outside of the compositional realm of MORB both in terms of trace element abundances and ratios. The reactive signature increases in strength up section, peaking in varitextured gabbros interpreted to represent the fossilised axial melt lens, indicating that reactive porous flow occurred on the scale of the entire lower crust. The enrichment of the melt is coupled with a strong trace element depletion of plagioclase, olivine, and, to a lesser extent, clinopyroxene cores, suggesting that these phases represent the residues of the reactions from which trace elements have been removed. The dominant role of reactive porous flow, and the resulting deviations from fractional crystallisation predictions, suggest that the lower oceanic crust plays a much more complex and significant role in modifying the compositions of MORB than previously expected, with consequent implications for models of mantle processes.
ISSN: 0012-821X

hal-00814075
https://hal.archives-ouvertes.fr/hal-00814075
DOI : 10.1016/j.epsl.2012.11.012

Éditeur(s) : HAL CCSD AGU and the Geochemical Society
Résumé : International audience
Peridotite xenoliths brought up to the surface by the volcanism of the Kerguelen Islands represent a mantle that has been affected by a high degree of partial melting followed by intense melt percolation above the Kerguelen plume. These xenoliths are therefore particularly suitable to investigate effects of melt-rock interaction on crystallographic fabrics (lattice-preferred orientation (LPO)) of peridotite minerals and on the LPO-induced seismic properties of peridotites above a mantle plume. We have studied a suite of 16 ultramafic samples representative of different degrees of partial melting and magma-rock interaction among which the protogranular harzburgites are the least metasomatised xenoliths and dunites are the ultimate stage of metasomatism. Olivine LPO is characterized by high concentration of [010] axes perpendicular to the foliation and [100] axes close to the lineation or distributed in the foliation plane in harzburgites, whereas the high concentration of [100] axes is parallel to the lineation and [010] axes is perpendicular to the assumed foliation in dunites. Olivine LPO in harzburgites is interpreted as being due to a deformation regime in axial compression or transpression. The fabric strength of olivine decreases progressively from protogranular to poikilitic harzburgites and finally to dunites, for which it remains nevertheless significant (J index 3.8). Seismic properties calculated from LPO of minerals indicate that metasomatism at higher melt/rock ratio lowers the P wave velocities. The most significant difference between harzburgites and dunites corresponds to the distribution of S wave anisotropy. Harzburgites display the maximum of anisotropy within the foliation plane and the minimum of anisotropy perpendicular to the foliation plane, whereas the lowest anisotropy is parallel to the lineation for dunites. These modifications of seismic properties as a result of metasomatic processes may induce seismic heterogeneities in the mantle above the Kerguelen plume. In addition, assuming a lithospheric mantle primarily harzburgitic and structured with a horizontal foliation, the seismic properties calculated for the Kerguelen xenoliths reconcile the rather high anisotropy evidenced by the horizontally propagating surface waves with the apparent isotropy revealed by the absence of splitting of vertically propagating teleseismic SKS waves recorded by the GEOSCOPE Kerguelen station.
ISSN: 1525-2027

hal-00366222
https://hal.archives-ouvertes.fr/hal-00366222
https://hal.archives-ouvertes.fr/hal-00366222/document
https://hal.archives-ouvertes.fr/hal-00366222/file/bascou_Kerguelen_2007GC001879_hal.pdf
DOI : 10.1029/2007GC001879

Éditeur(s) : Elsevier Science Bv
Résumé : The late Quaternary paleoceanography and paleoenvironment in the Okinawa Trough, East China Sea, have been well reconstructed over the last decade, while in contrast the provenance of terrigenous sediments that have accumulated there remains enigmatic. In this study, rare earth elements (REE) were used to investigate provenance changes in sediments from Core DGKS9604, taken from the middle Okinawa Trough. Discrimination plots based on REE fractionation parameters suggest that the cored sediments have variable provenances over the last 30 ka, with the lower part (ca. 31-8.2 ka) ultimately originating mostly from the Changjiang (Yangtze River) and the upper part (7.1-0 ka) primarily from Taiwan. During the Last Glacial Maximum and early deglacial period, sea level was low and the main stream of the Kuroshio Current was deflected to the east of the Ryukyu Islands. As a result the Changjiang-derived sediments might have dominated sedimentation of the middle Okinawa Trough. However, since about 7 ka the main stream of the Kuroshio Current strengthened in the area of the trough, as sea level approximated the modern position. This caused near-bottom transport of fine-grained sediments from the continental margin to the trough to become weak and instead, Taiwan-derived terrigenous sediments dominated in the middle trough. The changing provenances of terrigenous sediments into the middle Okinawa Trough are closely related to the evolution of oceanic circulation and sea level in the East China Sea. Two tephra layers in the core have distinct REE compositions and correlate well with two volcanic eruptions at 7.6 and 25.8 ka in southern Japan. (C) 2010 Published by Elsevier B.V.
Marine Geology (0025-3227) (Elsevier Science Bv), 2010-09 , Vol. 275 , N. 1-4 , P. 212-220

Droits : 2010 Published by Elsevier B.V.
http://archimer.ifremer.fr/doc/00013/12459/9402.pdf
DOI:10.1016/j.margeo.2010.06.002
http://archimer.ifremer.fr/doc/00013/12459/

Éditeur(s) : HAL CCSD Université des Antilles
Résumé : International audience
Cruise tourism is a sector that is rapidly expanding (16 million passengers in 2011). Today, cruising remains an essentially American affair, dominated by North American clients whose preferred destination is the Caribbean Sea. American cruise circuits continue to extend and diversify from the Panama Canal to the edge of Alaska. Meanwhile, cruises strengthen their position on the Mediterranean and Baltic Seas and has launched in East Asia from shores of the South China Sea to major rivers. Between continuity and recomposition, the cruise industry faces several challenges such as the limits of overcapacity (more than 6,000 passengers on board), its relationship with the host territories (ports of call), and the renewal of the “cruise” products.
Le tourisme de croisière est un secteur d’activité en pleine expansion (16 millions de passagers en 2011). De nos jours, la croisière reste encore une affaire essentiellement américaine, dominée par les clientèles nord-américaines, et dont le champ spatial privilégié est la mer des Caraïbes. Les circuits américains de la croisière s’étendent et se diversifient, du canal du Panama aux confins de l’Alaska. Parallèlement, la croisière conforte sa position sur les mers méditerranéenne et baltique et se déploie en Asie orientale, des rivages de la mer de Chine aux grands fleuves. Entre permanences et recompositions, l’industrie de la croisière doit relever plusieurs défis tels que les limites du gigantisme (plus de 6 000 passagers à bord), ses relations avec les territoires d’accueil (les ports d’escales), le renouvellement du produit « croisière ».
ISSN: 1779-0980

hal-01624751
https://hal.archives-ouvertes.fr/hal-01624751
DOI : 10.4000/etudescaribeennes.5629

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Region Gdansk Pomerania is an excellent geographic area for the development of yachting. Gdansk Bay and the Vistula Lagoon is characterized by very good weather conditions. Numerous advantages of anthropogenic and tourist resorts strengthen the attractiveness of the coast. The marina recently ended in Gdansk, Sopot and Gdynia create very good conditions for the development of yachting. The combination of the Gulf of Gdansk by the river network and channels Żuławy of the Great Masurian Lakes promotes the development of yachting in both the Gulf of Gdansk and Masurian Lake region. However, new infrastructure investments, realized with funding from the EU, like ‘Loop Żuławska’ and the new marina, leading to an increase in tourist traffic and threats to existing reserves and landscape parks. Another problem is the lack of regulation of the right on the crossing of the Strait of Baltiysk, leading from the Vistula Lagoon on the Baltic Sea, which is located in the territorial waters of Russia. The concentration of investments in the region of Żuławy contrasts with too little spending on development of tourist infrastructure in the Hel Peninsula. There are large disparities in tourist traffic. Tourism in Hel Peninsula significantly exceeded the absorption of tourism in the region and leads to the degradation of the local environment. In addition, the seasonality of tourism on the coast favours the trend of maximizing profit tourism enterprises. New, designed ditch the Vistula Spit, which connects directly to the Vistula Lagoon from the Baltic Sea, bypassing the Russian territorial waters, can lead to serious ecological changes.
La région de Gdansk en Poméranie est une excellente zone géographique pour le développement du yachting. La baie de Gdansk et la lagune de la Vistule se caractérisent par de très bonnes conditions climatiques. Divers avantages anthropiques et stations touristiques renforcent l’attractivité de la côte.Les marinas nouvellement terminées à Gdansk, Sopot et Gdynia, créent de très bonnes conditions pour le développement du yachting. La combinaison du golfe de Gdansk, du réseau fluvial et des canaux Żuławy qui relient les Grands Lacs de Mazuries, favorise le développement du yachting dans le golfe de Gdansk et la région des lacs. Les nouveaux investissements dans les infrastructures, réalisés grâce à des financements de l’Union européenne, tels "Loop Żuławska" et la nouvelle marina, conduisent à une augmentation de l’activité touristique qui menace les réserves existantes et les parcs naturels. L’autre problème est l’absence de réglementation relative au droit de passage dans le détroit de Baltiysk, menant de la lagune de la Vistule, qui est située dans les eaux territoriales de la Russie. Entre la concentration des investissements dans la région de Żuławy et les faibles dépenses pour le développement de l’infrastructure touristique dans la péninsule d’Hel, il existe de grandes disparités dans le trafic touristique. Les infrastructures touristiques de la péninsule d’Hel ne sont pas en mesure d’absorber les flux touristiques de la région et la situation conduit inéluctablement à la dégradation de l’environnement. La situation de la lagune de la Vistule, dont les eaux sont partagées entre la Russie et la Pologne, peut entraîner de graves changements écologiques.
Gdańsk
Pologne
Poméranie
Hel
Zulawy

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.10762
http://journals.openedition.org/etudescaribeennes/10762

Éditeur(s) : HAL CCSD
Résumé : International audience
We focus on some French BTS (Brevet de Technicien Supérieur / Advanced Technician Certificate), namely tourism and assistant manager, which are two important diplomas for the local development and in which microeconomic and management sciences plays a great part. The French BTS is a short Vocational Diploma prepared in two years after the “baccalauréat”, with national programs and evaluation criteria.The successful candidates are supposed to be immediately employable, especially in their local geographical environment. Thus, there exists a paradox between the national definition of the diploma and the local contexts of teaching and (supposed) professional integration. However, the professional traineeship plays a great part in this diploma. For this reason, it seems interesting to investigate how the conception of students evolve, with respect to the aforementioned paradox, during and after professional traineeship. For this purpose, questionnaire surveys have been carried out at various moment of the scholar during two years (two cohorts).The main results can be summarized as follows. The professional traineeship is positively perceived by the students at the beginning of the training. They consider it as very important for the development of professional skills. Over time, this positive representation progresses homogeneously. The students are convinced ofthe efficiency of professional traineeship: their professional project strengthened but, they also realize that their professional future will not necessarily be in Guadeloupe. This is probably linked with a better representation of the economic situation of Guadeloupe and shows, as excepted, that the context of the professional traineeship modifies the representation of students. For the BTS assistant manager, we specially note a degradation of the representation of the profession of assistant manager, whereas this training’s choice was realized with conviction.
20th GENERAL ASSEMBLY AND BIENNAL MEETING “ Biodiversity, Energy, Risks and Health from scientific knowledge to the emergence of innovative development strategies in the Caribbean”
Deshaies, Guadeloupe

hal-01535042
https://hal.univ-antilles.fr/hal-01535042

Éditeur(s) : Springer
Résumé : Series of sensitivity tests were performed with a z-coordinate, global eddy-permitting (1/4 degrees) ocean/sea-ice model (the ORCA-R025 model configuration developed for the DRAKKAR project) to carefully evaluate the impact of recent state-of-the-art numerical schemes on model solutions. The combination of an energy-enstrophy conserving (EEN) scheme for momentum advection with a partial step (PS) representation of the bottom topography yields significant improvements in the mean circulation. Well known biases in the representation of western boundary currents, such as in the Atlantic the detachment of the Gulf Stream, the path of the North Atlantic Current, the location of the Confluence, and the strength of the Zapiola Eddy in the south Atlantic, are partly corrected. Similar improvements are found in the Pacific, Indian, and Southern Oceans, and characteristics of the mean flow are generally much closer to observations. Comparisons with other state-of-the-art models show that the ORCA-R025 configuration generally performs better at similar resolution. In addition, the model solution is often comparable to solutions obtained at 1/6 or 1/10 degrees resolution in some aspects concerning mean flow patterns and distribution of eddy kinetic energy. Although the reasons for these improvements are not analyzed in detail in this paper, evidence is shown that the combination of EEN with PS reduces numerical noise near the bottom, which is likely to affect current-topography interactions in a systematic way. We conclude that significant corrections of the mean biases presently seen in general circulation model solutions at eddy-permitting resolution can still be expected from the development of numerical methods, which represent an alternative to increasing resolution.
Ocean Dynamics (1616-7341) (Springer), 2006-12 , Vol. 56 , N. 5-6 , P. 543-567

Droits : © Springer 2006. Part of Springer Science+Business Media
http://archimer.ifremer.fr/doc/2006/publication-3514.pdf
DOI:10.1007/s10236-006-0082-1
http://archimer.ifremer.fr/doc/00000/3514/

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Island arc picrites and boninites are magnesian magmatic rocks believed to be generated by high degrees of melting of depleted mantle sources fluxed by subduction-derived, volatile-rich components. These magmas can be probes of both the mantle wedge protoliths and subduction components, but are rare among other, usually more evolved, types of arc lavas. Furthermore, many arc picrites and boninites show evidence for late-stage differentiation prior to or during eruption, masking their primary, mantle-derived geochemical signatures. We report textural and chemical data on spinel-hosted melt inclusions of mantle origin in amphibole-bearing websterite veins cross-cutting spinel harzburgite xenoliths from the active andesitic Avacha volcano (south Kamchatka, Russia). The data are used to constrain the composition and origin of melts that formed the websterite veins in the sub-arc lithospheric mantle. The melt inclusions typically contain euhedral orthopyroxene and clinopyroxene and occasionally minor amphibole in silicate glass. The melt inclusions were homogenized using heating stages and gas-mixing furnaces. The homogenized glasses range from subalkaline primitive silica-rich picrite and high-Ca boninite (>15 wt % MgO, 48–54 wt % SiO2) to rhyolite. High-Ca boninite glasses have moderate volatile and low heavy rare earth element contents and elevated Cs, Rb, Ba, U, Sr, and Li abundances, with extremely high U/Th. In turn, the glasses display no negative spikes in the high field strength elements Nb, Ta, Zr, Hf, and Ti. We show that the silica-rich picrite and high-Ca boninite liquids in this study formed by high degrees of melting (>25%), at volatile under-saturation, of hybrid melt-depleted but silica-rich mantle sources at ≥1·5 GPa. The hybrid sources formed in two stages: first, by extraction of ∼15% melt from the convecting mantle to form a refractory protolith, which was subsequently enriched in silica via interaction with subduction-derived components prior to or during remelting in the mantle wedge. The subduction-derived components were enriched in fluid-mobile elements and probably oxidized. Overall, our results suggest that silica-rich picrites and high-Ca boninites can be primary melts in mature subduction zones and differentiate within the mantle wedge and the deep arc crust to form more evolved andesite magmas.
ISSN: 0022-3530

hal-01553676
https://hal.archives-ouvertes.fr/hal-01553676
DOI : 10.1093/petrology/egw066

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Thermal diffusivity of synthetic quartz single-crystals and natural polycrystalline aggregates were measured using a modified Angstrom method at ambient pressure and up to 800 degrees C in order to investigate the effect of crystal preferred orientation on thermal diffusivity of quartz rich rocks. The thermal diffusivity tensor of quartz was determined by measuring the thermal diffusivity of an oriented synthetic quartz single-crystal along the [100] and [001] directions. A naturally deformed, fine-grained quartzite mylonite, was used to compare the single crystal properties with aggregate properties. Using the crystal preferred orientations (CPO) measured by the Electron Back Scattered Diffraction (EBSD) method and the measured thermal diffusivity tensor of quartz, the three-dimensional aggregate thermal diffusivity was modelled using volume averaging models. In order to test the validity of these models that are only based on the properties of the constituent minerals, the thermal diffusivity was then measured on oriented cores as a function of temperature, along three orthogonal directions, parallel to the (X-lineation, Y, Z-pole to foliation) structural frame. Both modelled and direct measurement of thermal diffusivity show an anisotropy of thermal diffusivity, heat transport being more effective parallel to Y-direction and less effective parallel to the lineation X-direction. Thermal diffusivities measured in a given direction on the natural rock are lower by less than 10% than the modelled thermal diffusivity in the same direction, showing that rock imperfections have a weak effect on heat transport. In addition, the modelled thermal diffusivity anisotropy based on the characterization of crystal orientations and thermal diffusivity tensor shows a good agreement with measurements in both alpha and beta stability field. This validation of the petrophysical simulation allows for evaluating the 3D thermal diffusivity of quartz rich rocks in different crustal conditions. The 3D thermal diffusivity of five naturally deformed quartzites displaying quartz fabrics expected in different crustal pressure and temperature ranges were simulated. The resulting thermal diffusivity anisotropies of quartzites range between 40% and 10%, depending on temperature, crystallographic fabric patterns and fabric strength. Under crustal conditions, quartzites deformed in the granulite facies display a high thermal diffusivity in the (XZ) foliation plane, whereas quartzites deformed in greenschist facies have highest thermal diffusivity in the (Z) direction normal to the foliation plane.
ISSN: 0040-1951

hal-00413568
https://hal.archives-ouvertes.fr/hal-00413568
DOI : 10.1016/j.tecto.2008.11.006

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Both oedometric and plane-strain tests were performed with parallelepipedic samples made of synthetic granular, cohesive, frictional and dilatant rock analogue material GRAM2. For the first time parallel sets of fractures that have all the characteristics of natural joints were reproduced in the laboratory. The fractures are regularly spaced, normal to σ3, and have plumose morphology very similar to that of natural joints. These fractures can form at tensile stress σ3 much smaller in magnitude than the tensile strength of material and even at slightly compressive σ3. When mean stress σ exceeds a certain value, the fractures become oblique to σ1 (the obliquity increases with σ), forming networks of conjugate shear bands/fractures. These results of plane-strain experiments are in good agreement with those of better controlled conventional axisymmetric tests on a similar material in Chemenda et al. (2011b) and are closer to real geological situations. Both types of experiments are complementary. Their results lead to the conclusion that at least certain categories of natural fractures (including joints, and conjugate shear fractures/bands) were initiated as deformation localization bands. The band orientation is defined by the constitutive properties/parameters (notably the dilatancy factor) that are sensitive to σ.
ISSN: 0040-1951

hal-00795555
https://hal.archives-ouvertes.fr/hal-00795555
DOI : 10.1016/j.tecto.2011.11.021

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The identification of the structures and deformation patterns in magma-poor continental rifted margins is essential to characterize the processes of continental lithosphere necking. Brittle faults, often termed mantle detachments, are believed to play an essential role in the rifting processes that lead to mantle exhumation. However, ductile shear zones in the deep crust and mantle are rarely identified and their mechanical role remains to be established. The western Betics (Southern Spain) provides an exceptional exposure of a strongly thinned continental lithosphere, formed in a supra-subduction setting during Oligocene-Lower Miocene. A full section of the entire crust and the upper part of the mantle is investigated. Variations in crustal thickness are used to quantify crustal stretching that may reach values larger than 2000% where the ductile crust almost disappear, defining a stage of hyper-stretching. Opposite senses of shear top-to-W and top-to-E are observed in two extensional shear zones located close to the crust-mantle boundary and along the brittle-ductile transition in the crust, respectively. At locations where the ductile crust almost disappears, concordant top-to-E-NE senses of shear are observed in both upper crust and serpentinized mantle. Late high-angle normal faults with ages of ca. 21 Ma or older (40Ar/39Ar on white mica) crosscut the previously hyper-stretched domain, involving both crust and mantle in tilted blocks. The western Betics exemplifies, probably better than any previous field example, the changes in deformation processes that accommodate the progressive necking of a continental lithosphere. Three successive steps can be identified: i/a mid-crustal shear zone and a crust-mantle shear zone, acting synchronously but with opposite senses of shear, accommodate ductile crust thinning and ascent of subcontinental mantle; ii/hyper-stretching localizes in the neck, leading to an almost disappearance of the ductile crust and bringing the upper crust in contact with the subcontinental mantle, each of them with their already acquired opposite senses of shear; and iii/high-angle normal faulting, cutting through the Moho, with related block tilting, ends the full exhumation of the mantle in the zone of localized stretching. The presence of a high strength sub-Moho mantle is responsible for the change in sense of shear with depth. Whereas mantle exhumation in the western Betics occurred in a backarc setting, this deformation pattern controlled by a high-strength layer at the top of the lithosphere mantle makes it directly comparable to most passive margins whose formation lead to mantle exhumation. This unique field analogue has therefore a strong potential for the seismic interpretation of the so-called “hyper-extended margins”.
ISSN: 0264-8172

insu-01310895
https://hal-insu.archives-ouvertes.fr/insu-01310895
https://hal-insu.archives-ouvertes.fr/insu-01310895/document
https://hal-insu.archives-ouvertes.fr/insu-01310895/file/Frasca-MarPetGeol-2016.pdf
DOI : 10.1016/j.marpetgeo.2016.04.020