180 research outputs found

    El sistema deposicional del Golfo de León

    Get PDF
    El sistema deposicional del Golfo de León presenta una plataforma  constituida por varios prismas epicontinentales, un talud y unascenso continental entallados por numerosos cañones, y dos cuerpos deposicionales profundos de gran importancia: el abanico del Ródano y el «Acúmulo de los Cañones Pirenaicos)). Las evaporitas messinienses han jugado un papel determinante en la evolución morfo-sedimentaria de este sistema durante el Plio-Cuaternario

    Bibliografía de dorsales oceánicas

    Get PDF

    Perspectives laborals dels doctorats en enginyeries i arquitectura a Catalunya

    Get PDF
    La decisió d'emprendre un doctorat no és senzilla. Mentre que la durada i la intensitat de l'esforç necessaris per a assolir-lo es poden determinar raonablement bé, els beneficis professionals que es podrien aconseguir són difícils de conèixer, ja que depenen de les possibilitats d'inserció laboral dels futurs doctors. L'objectiu principal d'aquest article és proporcionar algunes dades sobre les perspectives laborals actuals a Catalunya dels doctorats en les àrees de tecnologies industrials, tecnologies de la informació i la comunicació (TIC), i arquitectura, construcció i enginyeria civil. A partir de les enquestes d'inserció laboral dels doctors que fa l'Agència per a la Qualitat del Sistema Universitari de Catalunya (AQU), l'article s'endinsa, per a cadascuna de les tres àrees esmentades, en el lloc de treball dels doctors, la necessitat de tenir la titulació de doctor per a accedir-hi i per a fer la feina que hi fan, el grau de satisfacció amb els estudis i amb la feina, i la valoració de la decisió de fer el doctorat que van prendre en el seu moment. Les dades que es presenten poden ser útils per als graduats que estiguin valorant seguir un doctorat en les àrees indicades. També poden interessar als responsables dels programes de doctorat, de cara a decidir l'orientació de la recerca que es duu a terme i el contingut de la formació associad

    Techniques for the non-destructive and continuous analysis of sediment cores. Application in the Iberian continental margin

    Full text link
    Sediment sequences are the most valuable record of long-term environmental conditions at local, regional and/or global scales. Consequently, they are amongst the best archives of the climatic and oceanographic history of the Earth. In the last few decades a strong effort has been made, both in terms of quantity and quality, to improve our knowledge regarding the evolution of our planet from marine and lake sediment records, and also from other records such as ice cores. Such an effort requires reinforcing the geographical coverage and achieving the highest possible robustness in the reconstruction of past environments. Such a target requires the optimization of the time resolution of the records and reconstructions so that fast, high frequency shifts, such as those occurring nowadays due to the on-going global warming, can be disentangled. Beyond paleoenvironmental research, other disciplines have also contributed significantly to the fast growing number of sediment cores already available worldwide. Knowing the physical state and the chemical composition of sedimentary deposits is essential for land management purposes and for many industrial applications. A number of key technological developments are now allowing the acquisition for the first time of massive amounts of multiple parameters from sediment cores in a non-destructive, fast, continuous, repetitive and high-resolution form. In this paper we provide an overview of the state-of-the-art continuous and non-destructive analytical techniques used by the geoscientific community for the study of sediment cores and we present some examples of the application of these methods in several studies carried out around the Iberian Margin

    Rapid response of benthic deep-sea microbes (viruses and prokaryotes) to an intense dense shelf water cascading event in a submarine canyon of the NW Mediterranean Sea

    Full text link
    A major dense shelf water cascading (DSWC) event occurred in 2005 downward the Cap de Creus Canyon (Gulf of Lion, NW Mediterranean Sea), which caused a significant change in environmental parameters and biological components. Here we describe the effects of this DSWC event on benthic microbes and on virus-prokaryote interactions, and we explore their implications on the functioning of the canyon's ecosystem. We collected sediment samples at increasing depths inside the canyon and in the adjacent deep continental margin over a period of five years, i.e. during and after the DSWC event, which led to the deposition of high amounts of fresh and labile organic matter that stimulated C production by benthic prokaryotes and increased their abundance and biomass. The enhanced prokaryotic metabolism, still evident 6 months after the DSWC event, was associated with high viral replication rates and prokaryotic mortality, which released 3.4-6.3 gC m−2 over such a 6 months period. Such values are up to 3-times higher than the yearly C-flux to the seafloor reported in this area in years without DSWC. We conclude that DSWC can significantly enhance benthic prokaryotic metabolism and C cycling through viral-induced prokaryotic mortality

    Evolución del sector septentrional del margen continental catalán durante el Cenozoico

    Get PDF
    Preliminary integrative analysis of the geological record in the onshore and offshore areas of the Northern Catalan continental margin, enable one to trace as far as the shelf edge, the main Eastem Pyrenean Paleogene contractive structures (axial zone antiformal stack, Figueres-Montgrí thrust-sheet, Vallfogona thrust) and their coeval foreland basin. These structures are cut by two major, NE-SW to NNE-SSW and NW-SE oriented, extensional fault systems. The activity of the NE-SW to NNE-SSW fault system (mainly Late Oligocene-earliest Miocene in age) would have resulted in most of the crustal extension and thinning recorded in this extensional margin of the Valencia Trough. On the other side the NW-SE faults were at least partially active as strike-slip faults during the Paleogene, with displacements which are difficult to be precised. Nevertheless these faults were mainly normal faults during Middle Miocene to Quatemary. Although the faults display minor slips than those of NE-SW orientation, they are closely related to a noticeable alkaline volcanic activity which denote they reach the lower litosphere. The Cenozoic stratigraphy in the Northern Catalan continental margin records and was influenced succesively by: 1) the Paleogene (Paleocene-Early Oligocene) upbuilding of the Pyrenean orogen and the evolution of its foreland basin; 2: the activity of the Late Oligocene-Early Miocene NE-SW to NNE-SSW faults and coeval lithospheric uplifting, both related to the the NW Mediterranean rifting; and 3: the later thermal subsidence of the continental margin developed during the Middle Miocene-Quaternary and which was opposite to the isostatic rebound of the Pyrenees and its southern foreland. Middle Miocene to Quaternary sedimentation related to the resulting total subsidence of the continental margin was modified by the generation of local depocenters. These depocenters resulted from the excavation of topographical depressions and the more or less simultaneous activity of the NW-SE faults. Some of these low lying zones were superimposed and accentuated pre-existing contractive Paleogene depressions. In some cases this fact controlled the develoment of significative Late Neogene depocenters and the location in the continental margin of some conspicuous Neogene and recent submanne canyons

    Microplastics transfer from a malfunctioning municipal wastewater oxidation pond into a marine protected area in the Colombian Caribbean

    Full text link
    Wastewater es un importante source de microplasticos (MPs) en acuático ecosystems, threatening su biodiversity y environmental services. Este estudio examina la contribución de MPs de los effluentes de municipal wastewater treatment pond system (WTS) al stream, que fluye en la Císpata marina protegida área (MPA) en el Colombiano Caribbean. Samples of influyente and effluente wastewater and sludge en el WTS se analyzaban para determinar la abundancia y los types of MPs. Adicionalmente, el wastewater flow rate se measured using a volumetric method, and its MP load calculated. Abundancia de MPs en el influyente y effluente de los WTS era 15 y 5 artículos L–1 de wastewater, y 11 y 4 elementos Kg–1 dw de sludge, respectively. Fiberos (67–75%) prevalecen en el wastewater, mientras que fragmentos (56–67%) eran predominantes en el sludge. Por lo que el removalo de MPs entre el WTS fue el 67%, el wastewater effluents está contribuyendo aproximadamente 1.3 millones de días–1 a la vuelta de la espalda al MPA. Las highlights de studia que funcionan como WTS causa sustancial MP discharges in sensitive acuático coastal ecosystems. Esta WTS requiere ongoing maintenance e improvisaciones para enseñar las long-term óptima operación y función de reducción pollutant loads y environmental risks en recipiente acuático ecosystems
    corecore