Éditeur(s) : CRILLASH : Centre de Recherches Interdisciplinaires en Lettres, Langues, Arts et Sciences Humaines Observatoire des Amériques - UQAM Université Libanaise
Extrait de : "Monde arabe et Amérique latine : confluence des dynamiques sociétales" : colloque international, les 3 et 4 mai 2018. Université des Antilles
Description : Dans cette communication, Frédéric LEFRANCOIS, Professeur à l'Université des Antilles, étudie le sentiment océanique qui rappelle la collection de nouvelles la plus emblématique de Salman Rushdie, The Moor's Last Sigh (1995) et East-West (1994) afin de mettre en évidence les aspects centraux de la relation de l'écrivain avec l'Occident. Ce faisant, une attention particulière sera accordée aux visions utopiques et contrastives de l'Europe dans le monde du réalisme magique qui structure son écriture. La pertinence de cette approche est fondée sur des preuves recueillies par la confrontation de la vie de l'auteur avec un nombre considérable de contradictions, comme être confiné dans le pays de l'ancien colonisateur pour des raisons de protection, ou avoir à faire face à la conception occidentale du « subaltern brown Other ».

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V18159
V18159

Éditeur(s) : Copernicus Gesellschaft Mbh
Résumé : Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria which ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, East America, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous more easily accessible shallow marine species were studied. We here provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to Marmara Sea, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 51 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae), and compared among families with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions, yet relatively little is known regarding their diversity and functioning apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on Oceans, we advocate for a better assessment of bivalve symbioses diversity in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2013 , Vol. 10 , N. 5 , P. 3241-3267

Droits : Author(s) 2012. CC Attribution 3.0 License.
http://archimer.ifremer.fr/doc/00133/24417/22431.pdf
DOI:10.5194/bg-10-3241-2013
http://archimer.ifremer.fr/doc/00133/24417/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We present new shear-wave splitting measurements performed at 16 stations on the East European Craton, and discuss their implications in terms of upper-mantle anisotropy for this geophysically poorly-known region. Previous investigations of mantle anisotropy in Central Europe have shown fast directions aligning smoothly with the craton's margin and various suggestions have been proposed to explain their origin such as asthenospheric flow or lithospheric frozen-in deformation.;Here, we aim at investigating the continuation of this shear-wave splitting pattern further to the East, into the East European Craton For the craton, the interpretation appears to be less ambiguous than for central Europe since several arguments support lithospheric anisotropy in this region 1) The large-scale coherence within either of the four constituting blocks and the significant variations between the blocks on a small-scale, 2) the weak correlation with absolute plate motion vectors, and 3) the good correlation between anisotropy and crustal features, for which we use magnetic field alignments as a proxy. Rattler good correlation of these magnetic features with seismic fast orientations strongly supports the idea of vertically coherent deformation throughout upper mantle and crust. The observed splitting orientations thus reflect the last tectonic events of each block. frozen-in into the lithosphere for hundreds of millions of years
ISSN: 0040-1951

hal-00475647
https://hal.archives-ouvertes.fr/hal-00475647
https://hal.archives-ouvertes.fr/hal-00475647/document
https://hal.archives-ouvertes.fr/hal-00475647/file/Wuestefeld_EEC_craton_SKS_Tphy2010_hal.pdf
DOI : 10.1016/j.tecto.2009.01.010

Éditeur(s) : HAL CCSD Oxford University Press (OUP): Policy P - Oxford Open Option A Oxford University Press (OUP)
Résumé : International audience
The Pyrenean mountain range is a slowly deforming belt with continuous and moderate seismic activity. To quantify its deformation field, we present the velocity field estimated from a GPS survey of the Pyrenees spanning 18 yr. The PotSis and ResPyr networks, including a total of 85 GPS sites, were installed and first measured in 1992 and 1995–1997, respectively, and remeasured in 2008 and 2010. We obtain a deformation field with velocities less than 1 mm yr−1 across the range. The estimated velocities for individual stations do not differ significantly from zero with 95 per cent confidence. Even so, we estimate a maximum extensional horizontal strain rate of 2.0 ± 1.7 nanostrain per year in a N–S direction in the western part of the range. We do not interpret the vertical displacements due to their large uncertainties. In order to compare the horizontal strain rates with the seismic activity, we analyse a set of 194 focal mechanisms using three methods: (i) the ‘r’ factor relating their P and T axes, (ii) the stress tensors obtained by fault slip inversion and (iii) the strain-rate tensors. Stress and strain-rate tensors are estimated for: (i) the whole data set, (ii) the eastern and western parts of the range separately, and (iii) eight zones, which are defined based on the seismicity and the tectonic patterns of the Pyrenees. Each of these analyses reveals a lateral variation of the deformation style from compression and extension in the east to extension and strike-slip in the west of the range. Although the horizontal components of the strain-rate tensors estimated from the seismic data are slightly smaller in magnitude than those computed from the GPS velocity field, they are consistent within the 2σ uncertainties. Furthermore, the orientations of their principal axes agree with the mapped active faults.
ISSN: 0956-540X

hal-01171752
https://hal.archives-ouvertes.fr/hal-01171752
DOI : 10.1093/gji/ggv052

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We present a new set of brittle microtectonic measurements carried out in the Pliocene and Quaternary rocks outcropping in several key sectors of the western Betic and Rif orogen, the so-called Gibraltar orogenic arc. This data set, along with available earthquake focal mechanisms and borehole breakouts, allowed us to compile the Pliocene and Quaternary stress map of this area. This map provides new constraints for tectonic models and the present-day tectonic activity of the proposed active eastward subduction of oceanic lithosphere beneath the Gibraltar Arc and roll-back. The horizontal maximum compressive stress (S-Hmax) is NW-SE in the Betic Orogen and N-S/NNW-SSE in the southern Rif Cordillera. There is a significant consistency between S-Hmax and the displacement field deduced from GPS measurements with respect to the African plate: both appear to reflect the NW-SE convergence between the African and the European plates that is perturbed in the Rif. We propose that part of the eastern Rif behaves as a quasi-rigid block welded to the stable African plate. This block is bounded by important faults that localized most of the deformation disturbing the stress and surface displacement field. Pliocene to Quaternary N-S to NW-SE Africa-Europe plate convergence seem to be associated to the reorganization of the remnant Early Miocene subduction system in a continental-continental collision framework. Three-dimensional reconstruction of available seismic tomography plotted against the intermediate seismicity shows that only part of the old subduction system, whose orientation ranges from N20 degrees E to N100 degrees E, remains active: the portion ranging from N30 degrees E to N40 degrees E, orthogonal to the regional convergence. (C) 2011 Elsevier Ltd. All rights reserved.
ISSN: 0264-3707

hal-00671033
https://hal.archives-ouvertes.fr/hal-00671033
DOI : 10.1016/j.jog.2010.12.003

Éditeur(s) : HAL CCSD
Résumé : The method of shear-wave splitting provides a unique possibility to identify seismic anisotropy, which is a result of the preferred orientations of the anisotropic minerals by deformation. The novel software SplitLab, presented in this thesis, simplifies the data processing. The comparison of three independent techniques makes it possible to associate an objective quality to the results and also to define a criterion to automatically detect events without splitting (“Nulls”). This criterion is applied to shear-wave splitting measurements at 16 stations located on the East European Craton. The results indicate that the fast directions reflect the ancient blocks, which constitute the East European Craton. The fast directions in south-west are aligned with the margin of the craton and continue the general tendency of offcraton stations. The stations in the Ural foredeep show fast directions perpendicular to the general tendency of the mountain chain. Various indicators give reason to assume lithospheric origins of anisotropy
La mesure du déphasage des ondes de cisaillement offre la possibilité de caractériser l'anisotropie sismique présente dans les différentes couches de la Terre, qui résulte généralement des orientations préférentielles des minéraux anisotropes induites par la déformation. Le nouveau logiciel SplitLab présenté dans cette thèse, simplifie le traitement des données depuis la requête des données jusqu'à la masure de déphasage et l'interprétation des résultats. La comparaison de trois techniques indépendantes pour mesurer ce déphasage permet de quantifier la qualité des résultats et de détecter automatiquement les mesures sans déphasage apparent. Ce critère est appliqué aux mesures de déphasages des ondes SKS enregistrées en 16 stations situées sur le Craton Est Européen. Les résultats indiquent que les directions rapides reflètent les structures anciennes, qui constituent le Craton Est Européen. En outre, les directions rapides dans le Sud-ouest s'alignent avec la bordure du craton et sont en continuité avec la tendance générale définie par les stations éloignées du Craton. Les stations dans les unités externes de l'Oural montrent des directions rapides perpendiculaires à la tendance générale de la chaîne de montagne.
https://tel.archives-ouvertes.fr/tel-00539114

tel-00539114
https://tel.archives-ouvertes.fr/tel-00539114
https://tel.archives-ouvertes.fr/tel-00539114/document
https://tel.archives-ouvertes.fr/tel-00539114/file/thesewustefeld.pdf

Éditeur(s) : Office Int Epizooties
Résumé : The tremendous development of penaeid shrimp culture across the world over the past twenty years has led to international trade in eggs, larvae and spawners of the best shrimp species for aquaculture. Trade has involved, in particular, the following species: - Penaeus japonicus from Japan to Europe, the Pacific Islands and South America - P. monodon from South-East Asia to almost all tropical countries - P. vannamei and P. stylirostris from countries along the Pacific coast of South and Central America to the United States of America, the islands of the South Pacific, countries along the Atlantic coast of the Americas and certain countries in Africa. In the 1980s, research conducted by American and French teams enabled the breeding of stocks of spawners in captivity. This resulted in the establishment of lines of captive broodstock outside natural areas of distribution, and the development of new breeding farms in previously unproductive regions. Trade related to movements of these species is facilitated by the absence of legislation in most countries; even when such legislation does exist, it is not always applied These practices have led to the rapid development of world shrimp production, but have also contributed to the dissemination of pathogens. In recent years, the occurrence of serious epizootics - occasioning heavy losses world-wide - has led to a more cautious approach involving trade of post-larvae obtained from captive broodstock in which thorough control measures have been implemented for known diseases. Trade in wild shrimp will probably be abandoned progressively, to avoid the risk of introducing new pathogens. The main challenges for research in the near future are the development of diagnostic tools, to enable continuous control of captive broodstock, and the selection of strains which are resistant to the principal pathogens affecting these species.
Revue Scientifique Et Technique-office International Des Epizooties (0253-1933) (Office Int Epizooties), 1996-06 , Vol. 15 , N. 2 , P. 499-515

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00091/20231/17883.pdf
http://archimer.ifremer.fr/doc/00091/20231/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The N-S Languedoc volcanic province between the French Massif Central and the Mediterranean Sea is characterized by sporadic scattered low volume (similar to 2 km(3)) and geochemically homogeneous alkali basaltic activity spanning from 161 to 05 Ma The existence of magmatic activity of such a long duration within such a small area (similar to 140 km long and similar to 60 km wide) in spite of the extensive shift to the East of the European plate (about 2500 km during the last 160 Ma) is problematic Trace-element abundances in lavas suggest low degrees of melting (1-5%) in the spinet-garnet transition zone of an enriched Iherzolitic source The lavas display rather large ranges in Sr isotopic ratios (0 70307-0 70436) The Nd-143/Nd-144 ratio variations are smaller (0 51268-0 51300) and these of Pb-206/Pb-204 Pb-208/Pb-204 and Pb-207/Pb-204 are 18 745-19 515 38 53239 228 and 15 567-15 680 respectively The Languedoc lithospheric mantle as sampled by xenoliths is globally similar to the Pyrenees lithosphere The xenoliths show also rather large Sr Nd and Pb isotopic variations (Sr-87/Sr-86 0 70287-0 70578 Nd-143/Nd-144 0 51256-0 51414 Pb-208/Pb-204 37772-39 041 Pb-206/Pb-204 17 901-19 353) except for Pb-207/Pb-204 (15 570-15 620) The Pb-206/Pb-204 and La/Sm ratios are positively correlated both in xenoliths and lavas The increase of the Pb-206/Pb-204 (which could be interpreted as participation of the European Asthenospheric Reservoir EAR) is probably related to volatile-rich (carbonated?) fluid percolation This is corroborated by LILE and HFSE patterns observed in several xenoliths Therefore our data on lavas and xenoliths suggest a lithospheric origin for this long lived magmatism We propose (1) that the role of the asthenosphere in the Languedoc volcanism was restricted to volatile-rich fluid supplying and (2) that the fluid injection within the lithosphere may be related to the arrival of the Central Atlantic Plume head beneath Western Europe about 70 Ma ago In this model the isotopic signature of the oldest lavas (>70 Ma) would be that of the mantle lithosphere inherited from Hercynian processes The signatures of the subsequent lavas would be driven by the metasomatic component stored within the lithosphere and preferentially mobilized during incipient melting This metasomatised lower lithosphere was close to its solidus and small changes in P (or T) triggered incipient melting leading to basaltic volcanism Successive local re adjustments of the lithospheric blocks which accompanied the Meso-Cenozoic evolution of the Thetys Ligurian margin towards the present Mediterranean margin are the probable cause of these changes and so the sporadic volcanic activity in Languedoc is unrelated to deep asthenospheric processes
ISSN: 0024-4937

hal-00558884
https://hal.archives-ouvertes.fr/hal-00558884
DOI : 10.1016/j.lithos.2010.04.009

Éditeur(s) : HAL CCSD
Résumé : International audience
The development of the mine, gas and oil extraction in the Eastern Venezuela (Oriente and Guayana regions) and the Far Eastern (Oriental Siberia) is characterized by the emergence of pioneer small and medium cities during the last fifty years and an emerging process of metropolisation since 2000 (Yakutsk, Ciudad Guayana). In Eastern Venezuela, the urbanization is partially planned, generally “spontaneous”. In Yakutia, dynamics of urbanization is planned. In the both cases, urban dynamics is driven by the exploitation of the natural resources and the immigration. With the collapse of the Soviet Union, some mining towns disappeared in the 1990 and 2000. Since the beginning of the 2010’s mining urban regions are under a double process of territorial integration with Russian Europe and Asia. In Venezuela, small and medium sized cities are growing with the emergence of new mining territories and the exploitation of the Orinoco Belt (extra heavy oil). This article analyses the main territorial dynamics of these small and medium sized cities.
Digital Cities and Spatial Justice

ISBN : 978-84-697-4984-5
hal-01584550
https://hal-amu.archives-ouvertes.fr/hal-01584550