611 research outputs found
Submarine emissions on the seafloor: from cold sepes to hot vents
The main types of submarine geological emissions are classified as cold seeps (hydrocarbons and brines)
and hot vents. These processes result in the emission of geological fluids: brine, gases (mainly hydrocarbons), sediments and rocks. Submarine emissions are associated with an intensive geological, geochemical, thermal and biological activity (Judd and Hovland, 2007), and constitute a key process in the
dynamics of the global cycles of the planet Earth. These systems play a major role in the exchange of
matter and energy between the Geosphere and Hydrosphere, contributing to the greenhouse gases and
affecting the ocean chemistry (Dimitrov, 2002; Alt, 2003). They also control the evolution of continental
margins and oceanic basins (Paull y Dillon, 2001), and can produce the formation of significant and
strategic mineralizations, as well as focus the development of specific habitats (Boetius et al., 2000) and
provide an insight of deeper parts of the crust.LIFE+ INDEMARES/CHICA (LIFE07/NAT/E/000732), CADHYS (P08-RNM-03581), MONTERA (CTM2009-14157-C02), VULCANO (CTM2012-36317) and SUBVENT (CGL2012-39524-C02)
Tectonic model for the latest Triassic-Early Jurassic extensional event in and around the Iberian Peninsula
An array of 200-Ma-old (Lower Jurassic) dolerite dikes in both the eastern and western sides of the Atlantic records an episode of SE directed extension which occurred in and around the Iberian Peninsula. This extensional regime episode is responsible for the formation of the main
structures in the Iberian Peninsula and neighboring areas at the beginning of the Jurassic
Grafted Sepiolites for the Removal of Pharmaceuticals in Water Treatment
The increased detection of pharmaceuticals in finished drinking water has become a growing cause of concern in recent years. The removal of atenolol, ranitidine, and carbamazepine by sepiolite, following functionalization of its surface by organosilane grafting, constituted the subject of this investigation. Silylated surfaces include octyl, γ-aminopropyl, 3-chloropropyl, and triphenyl moieties. The sorption of atenolol and ranitidine was higher on sepiolite functionalized with 3-chloropropyl, while carbamazepine showed a higher sorption on sepiolite with triphenyl groups. Filtration experiments of both ranitidine and carbamazepine on octyl- and triphenyl-sepiolite, respectively, showed a higher retention of ranitidine in comparison to carbamazepine, in spite of the fact that the number of sorption sites was lower due to its higher binding rate.Ministerio de Educación y Cultura CTM2013-42306-R, CTM2016-77168-
INFORME CIENTÍFICO – TÉCNICO. Campaña MONTERA‐0412
Informe de la campaña oceanográfica del proyecto MONTERA. Resultados preliminares de la campaña.La campaña MONTERA‐0412 se ha realizado A lo largo de dos zonas de los márgenes continentales del sur de Iberia: el Golfo de Cádiz y el Mar de Alborán. Ambas zonas se
caracterizan por la presencia de montes submarinos y la existencia de una intensa
actividad tectónica reciente. En el Golfo de Cádiz se estudiaron el Banco de Portimao,
relacionado con estructuras diapíricas, y el Banco del Guadalquivir que es un alto de
basamento reactivado; por otro lado los bancos estudiados en el Mar de Alborán (Bancos de Avempace, La Herradura e Ibn Batouta junto con la propia dorsal de Alboran) son en todos los casos altos de basamento bético y/o volcánico, cuya última generación de relieve está generada, así mmismo, por la actividad de estructuras tectónicas.
La adquisición de nuevos datos permitirá evaluar la tasa de elevación del Banco de
Portimao, así como la generación de deslizamiento cohetáneos con dicha elevación. En la zona del Banco del Guadalquivir se tendrá un mejor control de la interferencia de la Masa de Agua Mediterránea con los rasgos morfológicos del margen continental. Por último los datos obtenidos en el Mar de Alborán han permitido analizar por primera vez algunos cuerpos sedimentarios, fundamentamentalmente abanicos profundos y
deslizamientos relacionados con los montes submarinos de esta zona, en este sentido se
ha caracterizado batimétrica, sísmica y sedimentológicamente un nuevo deslizamiento
que hemos denominado “Deslizamiento Montera”.
ResumenMONTERA‐0412 scientific cruise has been conducted along two areas of the continental
margins of southern Iberia: the Gulf of Cadiz and the Alboran Sea. Both are characterized
by the presence of seamounts and the existence of intense recent tectonics activity. In
the Gulf of Cadiz have been studied the Portimao Bank, related to diapiric structures, and
the Guadalquivir Bank which is a reactivated basement high. In the Alboran Sea, the
surveyed banks (Avempace, La Herradura, Ibn Batouta and the Alboran Ridge) are betic
basement blocks or volcanic peleoreliefs, but in all cases they must be reactivated by
Neogene‐Quaternary tectonic activity.
The acquisition of new data enable the uplifted rate asessment of the Portimao Bank and
their relation to simultaneous submarine mass flow processes. In the area of the
Guadalquivir Bank could be expected a better control of the Mediterranean Water Mass
interaction with the morphological features of the continental margin. Finally the data
obtained in the Alboran Sea have allowed first analyze some deep sedimentary bodies,
basicly deelp sea fans and landslides related to main seamount, in this sense has been
characterized bathymetric, seismic and sedimentologically a new mass flow deposit
called "Montera Slide".A campanha oceanográfica MONTERA‐0412 foi realizada ao longo de duas áreas das
margens continentais do sul da Península Ibérica: o Golfo de Cádiz e o mar de Alborán.
Ambas as áreas são caracterizadas pela presença de montes submarinos e pela
existência de atividade tectónica no Neogeno‐Quaternário. No Golfo de Cádiz foram
estudados o Banco do Portimão e as estruturas diapíricas relacionadas, e o Banco do
Guadalquivir um alto de soco paleozóico reativado, por outro lado,os bancos
pesquisados no Mar de Alboran (Bancos Avempace, La Herradura, Ibn Batouta e Dorsal
de Alboran) sãoem todos os casos formados por altos de soco bético e/ou vulcânico e
também por atividade tectónica.
A aquisição de novos dados, permitirá a avaliação da taxa de soerguimento do Banco de
Portimão e a geração de deslizamento simultâneos com essa elevação. Na área do Banco
Guadalquivir ter‐se‐á ummelhor controle da interferência da massa de água do
Mediterrâneo com as características morfológicas da margem continental. Finalmente,
os dados obtidos no mar de Alborán permitiram analisar primeiramente alguns corpos
sedimentares profundos, fundamentamentalmente deslizamentos de terra relacionados
com os montes submarinos nesta área, e neste sentido foi caracterizado batimétrica e
sísmicamente um novo deslizamento que chamámos "Deslizamento Montera".Le Mission scientifique MONTERA‐0412 a été menée dans deux zones des marges
continentales du sud de l'Ibérie: le golfe de Cadix et la mer d'Alboran. Les deux régions
sont caractérisées par la présence de monts sous‐marins et l'existence d'une intense
activité tectonique récente. Dans le golfe de Cadix ont été étudiés le Banque du
Portimao, et les structures diapíriques connexes, et le Banque du Guadalquivir qui est un
10
bloc du zocalo réactivé, de l'autre côté des banques étudié dans la mer d'Alboran
(Avempace, La Herradura, Ibn Batouta et la dorsale d’Alboran) sont dans tous les cas
blocs du zocle Betico et/ou dernières reliefs volcaniques, et aussi sont généré par
l'activité tectonique.
L'acquisition de nouvelles données permettant d'évaluer le taux d'élévation de la Banque
du Portimao et la génération de glisser cohetáneos. Dans la Banque du Guadalquivir
aurez un meilleur contrôle de l'interférence de la messe de l’eau méditerranéenne avec
les caractéristiques morphologiques de la marge continentale. Enfin, les données
obtenues dans la mer d'Alboran ont permis analyser certains corps sédimentaires
profonds, fondamentalement glissements de terrain liés au monts sous‐marins dans ce
domaine, en ce sens a été caractérisé bathymétrique, sismique et les sédiment d’un
nouveau glissement "Montera Slide".PROGRAMA NACIONAL DE I+D+I. CTM2009-14157-C0
El complejo de lóbulo del sistema turbidítico distl de Almeria: arquitectura e historia deposicional durante los últimos 575.000 años
This paper presents the stratigraphic architecture of the lobe
complex (LC) of the distal Almeria turbidite system over the last 575
ka based on very high-resolution data (seismic parametric sub-bottom profiles, bathymetry and stable oxygen isotope core data). Its
depositional architecture suggests the 575 ka oldest lobe represents
a lobe system, which is essentially organized in vertical stacking of
channel-levee/lobes. Their morpho-sedimentary characteristics
point to: (i) this turbidite system roughly matches that of mixed sandmud composition systems; and (ii) the lateral relocation of turbidites
may be conditioned by factors such as the sediment load, the energy
of gravity flows, related avulsion processes and the local morphological confinement. The detailed seismofacies analysis enabled the
identification of channel-levee/lobes, mass-transport deposits and
hemipelagites formed over the last 269 ka. Their lateral and vertical
distribution suggests that an increased submarine canyon activity
and mass-movements took place during lowstand stages (MIS 8,
MIS 6, MIS 4 and MIS 2) whereas hemipelagic settling dominated
during the highstand stages (MIS 7 and MIS 5)Se presenta la arquitectura estratigráfica del complejo de lóbulo
(LC) del sistema turbidítico distal de Almería de los últimos 575 ka
basada en datos geológicos de muy alta resolución (perfiles sísmicos
paramétricos, batimetría e isotopos estables de oxígeno). Su arquitectura deposicional sugiere que el lóbulo más antiguo (575 ka) está
organizado por el apilamiento vertical de complejos de canal-dique/
lóbulo. Sus características morfo-sedimentarias apuntan a: (i) su
coincidencia con las de los sistemas mixtos de composición areno
fangosa y que (ii) la reubicación lateral de los depósitos turbidíticos
pudo estar condicionada por la carga de sedimento, la energía de los
procesos gravitacionales, los procesos de avulsión y el confinamiento
local. El análisis detallado de las sismofacies permite la identificación
de lóbulos canalizados, depósitos de transporte en masa, y hemipelagitas formados durante los últimos 269 ka. Su distribución lateral
y vertical sugiere que la actividad del cañón submarino y los movimientos en masa fueron mayores durante las etapas de bajo nivel
del mar (MIS 8, MIS 6, MIS 4 y MIS 2) y la sedimentación dominante
sería hemipelágica durante las etapas de alto nivel del mar (MIS 7
y MIS 5
Submarine Active Faults and MorphoTectonics Around the Iberian Margins: Seismic and Tsunamis Hazards
The aim of this work is to make a synthesis at regional scale focused on the geophysical characterization of submarine faults around the Iberian margin to identify active structures and analyze their development in the framework of the present plate organization. Most of these submarine faults show seabed morphological expressions mapped with high-resolution swath bathymetry data, high-resolution parametric sub-bottom profiles and multichannel seismic profiles. Present active tectonics, deformation, seismicity, and tsunami-affected coastal areas is mainly focused on south Iberia at the Eurasian and Nubia plate boundary. Submarine active faults in these areas are represented by long strike-slip fault systems and arcuate fold-thrust systems. Their development takes place in response to present NW-SE convergence between the Eurasian and Nubia plates. We propose a strain partitioning model of the plate boundary into simple and pure shear zones to explain the distribution and mechanisms of active submarine faults along the Gulf of Cádiz, Gibraltar Arc and Alborán Sea in response to the present-day shear stress orientation. Nevertheless, deformation is also focused in the NW Iberian margin. Thus, along the Galician and Portuguese margin, several submarine faults mapped as thrust fault systems with high-seismic activity along the Iberian ocean-continent transition reflect the re-activation of former structures. We suggest that submarine active faults in the NW and W Iberia are also the response to the eastwards transfer of short-offset transform faults of the Mid Atlantic Ridge into the oceanic Iberian along a weakness as the former plate boundary between the oceanic Iberia and Eurasia domains. The distribution and activity of submarine faults mapped in this work from geophysical and bathymetric data are in good agreement with geodetic data and focal mechanisms.Versión del edito
Spatial distribution of radionuclides in marine sediments from Djibouti seamounts (Alboran Sea, Western Mediterranean).
Sediment samples from two seamounts of the Djibouti Banks area – Avempace and Herradura - located at the Motril Marginal Plateau (northern Alboran Sea) were investigated to determine the radioactivity of natural and artificial radionuclides. Changes in the elemental composition of sediment from seamounts may be related to sources and oceanographic conditions in the water column, but also biogeochemical and geochemical processes can be involved during the vertical deposition of particles and in the sediment surface once particles are settled. The particular interest of this area is that the influence of fluvial supplies is scarce and therefore the contribution of aeolian dust inputs to sediments is expected to be high and largely responsible for the sediment’s composition. In this setting, the Sahara and northernmost part of North Africa or Sahel regions are the most likely areas providing dust particles to the Mediterranean Sea.
The tops of the Avempace and Herradura seamounts are relatively flat and shallow, with minimum depths of 260–275 m, respectively. In general, both seamounts presented similar average radiological load and the results showed that the spatial distribution of radionuclides was relatively uniform in surface sediments from these two banks. For the anthropogenic 137Cs, the radioactivity ranges from 1.8-6.9 Bq/Kg and can be mainly attributed to the significant supply of aeolian dust from North Africa to the Alboran Sea.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Estructura y resiliencia social en comunidades indígenas : el caso de la Unión de Palmeadoras de Tlaxiaco, Oaxaca, México
Las capacidades de resiliencia de comunidades indígenas pueden ser verificadas a través de su análisis como sistemas meso reticulares, abordando la fortaleza de sus estructuras en red endógenas y exógenas. El presente artículo analiza, desde el enfoque de redes sociales, el proceso de consolidación y persistencia organizativa de la Unión de Palmeadoras, integrada por mujeres mixtecas que se dedican a la elaboración y venta de tortillas artesanales. Las preguntas a responder, fueron: ¿cuál es la estructura social que dinamiza a la Unión de Palmeadoras de Tlaxiaco? ¿Para qué les ha servido formar parte de la unión? ¿Cuáles son las capacidades de resiliencia de la unión, considerando dicha estructura social? Los datos se obtuvieron en 2015 mediante un cuestionario aplicado a las 89 mujeres que integran la Unión. Los resultados muestran que la Unión de Palmeadoras es una estructura social con determinadas capacidades de resiliencia, derivadas de los procesos de cohesión, inclusión y competencia generados en su interior, pero también, una organización sumamente frágil debido a procesos endógenos y exógenos de su entorno local y regional.The resilience capacities of indigenous communities can be seen as reticular mesosystems by focusing on their endogenous and exogenous social networks. In this paper, we analyze, from the perspective of social networks analysis, the consolidation process and the organizational persistence of the Unión de Palmeadoras, in Tlaxiaco city, Oaxaca, México, which is integrated by mixtec women devoted to the elaboration and sale of handmade tortillas. Some of the question to be answered were: what is the social structure that dynamizes the Unión de Palmeadoras? What has been the use of being part of the organization? What are the resilience capacities that the Union has developed? Data were obtained in 2015-2017 by applying a questionnaire to the 89 women who make up the Union. Results indicate that women's networks can generate social support mechanisms, so the Union of Palmeadoras has developed certain qualities of resilience and fragility, which are derived from the inner processes of cohesion, inclusion and competitiveness, but also by exogenous processes of its local and regional environment
Origin of morphological depressions on the Guadalquivir Bank uplifted area (Gulf of Cadiz middle slope)
We have investigated the origin of morphological depressions (circular-elliptical depressions, amphitheatre-shaped escarpments and valleys) on the Guadalquivir Bank uplifted area (Gulf of Cadiz middle slope). This work is based on swath bathymetry and high- and mid-resolution reflection seismic datasets. Depressions occur on the distal (depositional) sector of the Gulf of Cadiz Contourite Depositional System, which has been developed under the influence of the Mediterranean Outflow Water (MOW). The Guadalquivir Bank is a NE-oriented relief that was uplifted along the Neogene and Quaternary. It forms the southern limit of the Bartolomeu Dias and Faro Sheeted Drift (SD) plateaus that are separated by the NW-trending Diego Cao Contourite Channel. Circular-elliptical depressions occur on the Bartolomeu Dias SD plateau, aligned parallel to the rim of the Diego Cao Channel. Irregular, crescent-shaped depressions occur to the SE of the study area and a valley surrounds the Guadalquivir Bank. The origin of these features is interpreted as the result of the interplay between oceanographic, mass-wasting, tectonic and fluid-escape processes. Four stages define the development of these features: 1) Onset of a contourite mounded drift associated with a proto-Diego Cao moat originated by a weak MOW circulation as it interacted with the structural features of the Guadalquivir Bank during the Lower Pliocene; 2) Evolution to a more complex multi-crest drift and moat system, probably as a result of an enhanced MOW and increased deformation of the underlying structures during the Upper Pliocene-Early Quaternary; 3) Event of enhanced tectonic activity that provoked widespread mass-wasting events along middle slope sheeted drift plateaus during the Mid Pleistocene. It was recorded in a prominent erosive surface under the present-day Diego Cao channel western rim and numerous slide scars displaying amphitheatre shapes on the limits of the plateaus; 4) Final stage (Late Quaternary) when the Mediterranean Intermediate Branch started flowing towards the N-NW along the deep gateway that was opened as a result of the mass-wasting event and/or structural adjustments. The contourite system evolved, due to tectonic events, to the present-day channel and a complex separated drift that includes circular depressions. They result from the interaction between the bottom current and the irregular basal surface created by the slide scars. During this phase, crescent-shaped depressions were created, probably by the interplay between bottom currents and fluid escape processes, and the marginal valley around the Guadalquivir Bank resulted from current reworking of the irregular topography of contouritic deposits affected by slide scars
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