19 research outputs found
The Interactive Role of Hydrocarbon Seeps, Hydrothermal Vents and Intermediate Antarctic/MediterraneanWater Masses on the Distribution of Some Vulnerable Deep-Sea Habitats in Mid Latitude NE Atlantic Ocean
In this work, we integrate five case studies harboring vulnerable deep-sea benthic habitats in different geological settings from mid latitude NE Atlantic Ocean (24–42º N). Data and images of specific deep-sea habitats were acquired with Remoted Operated Vehicle (ROV) sensors (temperature, salinity, potential density, O2, CO2, and CH4). Besides documenting some key vulnerable deep-sea
habitats, this study shows that the distribution of some deep-sea coral aggregations (including scleractinians,
gorgonians, and antipatharians), deep-sea sponge aggregations and other deep-sea habitats are influenced by water masses’ properties. Our data support that the distribution of scleractinian reefs and aggregations of other deep-sea corals, from subtropical to north Atlantic could be dependent of the latitudinal extents of the Antarctic IntermediateWaters (AAIW) and the Mediterranean Out- flow Waters (MOW). Otherwise, the distribution of some vulnerable deep-sea habitats is influenced,
at the local scale, by active hydrocarbon seeps (Gulf of Cádiz) and hydrothermal vents (El Hierro, Canary Island). The co-occurrence of deep-sea corals and chemosynthesis-based communities has been identified in methane seeps of the Gulf of Cádiz. Extensive beds of living deep-sea mussels (Bathymodiolus mauritanicus) and other chemosymbiotic bivalves occur closely to deep-sea coral
aggregations (e.g., gorgonians, black corals) that colonize methane-derived authigenic carbonates
High-resolution multibeam bathymetry of the northern Mid-Atlantic Ridge at 45–46° N: the Moytirra hydrothermal field
This work presents a new high-resolution multibeam bathymetric map of a segment of active deep sea-floor spreading in the Atlantic Ocean, the northern Mid-Atlantic Ridge (MAR) at 45–46º N. New high-resolution bathymetry data were acquired using an Atlas multibeam echosounder onboard the research vessel Sarmiento de Gamboa during the EXPLOSEA-2 survey in 2019. The final map of the MAR (50 m cell grid size) at the original scale of 1:200,000 shows a segment of 140 × 35 km of the MAR, at water depths from 715 to 3700 m. This new high-resolution bathymetric map allows to better defining the submarine morphology of the Moytirra hydrothermal active field, the only high-temperature field identified between the Azores Archipelago (Portugal) and Iceland. ROV submarine observations reaching the deepest part of the system for the first time show giant anhydrite-sulfide chimneys up to 20 m high, active strong black smokers and polymetallic massive sulfides
Multidisciplinary Scientific Cruise to the Northern Mid-Atlantic Ridge and Azores Archipelago
This work presents the preliminary result of the multidisciplinary cruise EXPLOSEA2
surveying the northern Mid-Atlantic Ridge and Azores Archipelago from 46 300 N to 38
300 N aboard the R/V Sarmiento de Gamboa and ROV Luso over 54 days (June 11 to
July 27, 2019). In this cruise report, we detail the geophysical, hydrographic, geological,
oceanographic, ecological, and microbiological data acquired and a brief of main
findings. The cruise addressed the exploration and comprehensive characterization
of venting sites, including the water column, the sediments and rocks that host the
hydrothermal activity, and the associated mineralizations, biology, and microbiology.
Deep hydrothermal chimneys and massive sulfide deposits (up 3,000 m in depth) within
the Moytirra hydrothermal active field were identified on slopes that had not been
explored previously. Another striking finding made during the EXPLOSEA2 cruise was
the field of carbonate chimneys named the “Magallanes-Elcano” field, a potentially relict
ultramafic-hosted hydrothermal site sourced by abiotic methane. This field is related to a
serpentinite and gabbro rock outcropping on a dome-shaped massif named the “Iberian
Massif.” An outstanding finding of the EXPLOSEA2 survey was the identification of the
first garden of soft corals growing after active submarine eruptions were reported in the
Azores Archipelago composed by a high density of soft corals the suborder Alcyoniina
at the summit and flanks of a recent volcanic cone at 160 m water depth developed
during the 1957–1958 eruption of Capelinhos. Several cold-water coral habitats formed
by colonial scleractinians (e.g., Lophelia pertusa and Madrepora oculata), coral gardens
composed of mixed assemblages of black corals (Leiopathes sp.), and octocorals and
dense aggregations of the glass sponge Pheronema carpenteri that may be classified as vulnerable marine ecosystems (VMEs) have been discovered during the EXPLOSEA2
cruise along the northern Mid-Atlantic Ridge. This work reveals the importance of
multidisciplinary surveys to the knowledge of deep-sea environments
Volteando la tortilla. Género y maíz en la alimentación actual de México.
Ante escenarios complejos, patriarcales y desoladores que dejan ver el neoliberalismo, la globalización agroalimentaria, el calentamiento global y las contaminaciones de granos nativos por la imposición de transgénicos, nos cuestionamos si existen algunas alternativas para preservar el maíz nativo como un recurso multiestratégico (alimentario, económico, cultural, ecológico y tecnológico) tomando en cuenta las condiciones actuales de desigualdades sociales de género, etnia, clases y edad que predominan en el campo mexicano. Para responder a algunos cuestionamientos, este libro presenta algunas alternativas a través de diversas experiencias femeninas y de relaciones de género en torno al maíz y la alimentación. Todas ellas muestran que es posible construir una masa crítica para salvaguardar el maíz nativo bajo esas condiciones desoladoras, pero siempre y cuando se “voltee la tortilla”, metáfora que da pie al inicio de otra realidad humanizada y en sincronía con la naturaleza.Proyecto realizado con financiamiento Conacy
Role of age and comorbidities in mortality of patients with infective endocarditis
[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.
[Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.
[Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality.
[Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
Geochemical and Limnological Characterization of the Corta Atalaya Pit Lake (Riotinto Mines, Spain)
This study examines some relevant limnological and hydrogeochemical characteristics of the most emblematic pit lake of the Iberian Pyrite Belt (IPB). Corta Atalaya (CA) open pit mine is known for its large size and for being one of the most important exploitations of copper in Europe. Despite its historical importance, little is known about the lake formed in this open pit. During this study, the pit lake presented a surface area of 16 ha, a maximum depth of 106 m, and a 5.8 hm3 volume of acid and metal-enriched water. CA pit lake shows permanent chemical stratification (meromictic lake), where three layers with different density and chemical composition can be differentiated: (i) a superficial layer of 5 ± 2 m water depth, with electric conductivity (EC) between 5.4–6.64 mS/cm, and oxygenated and Fe(III)-rich mixolimnion; (ii) an intermediate layer (between 5–30 m, chemocline), exhibiting strong vertical changes in parameters such as temperature (T) and EC, which show an increase with depth; and (iii) a thick bottom layer from 30 m to 106 m depth, with anoxic, elevated EC (47 mS/cm) and T (32 °C) values, and a concentration of Fe as Fe(II) (monimolimnion).The characterization of the water column is essential to know the potential sources of strategic and critical raw materials, and to evaluate their possible recuperation, thereby activating a circular economy
Mineral microbial precipitation of subseafloor fluids at the submarine Tagoro Volcano hydrothermal system (El Hierro, Spain)
[EN] Microbial organisms are known to participate in the (bio)mineralization and (bio)precipitation of certain compounds as found in hydrothermal vents. This includes metabolic processes acting directly on the precipitate formation (iron-oxidation, sulfate-reduction) or indirectly by the acceleration of mineralization promoted by the presence of microbial cells that act as nucleation sites, such as for opal-A. Here, we present the findings of different microbial precipitation processes at a novel low-temperature and shallow-water hydrothermal system at the summit of the Tagoro volcano (80–120 m water depth). This system is characterized by seafloor and basanite-hornitos covered by Fe-flocculate deposits, with micro-cracks and degasification vesicles filled mostly by pyrite and covered by sulfur-oxidizing bacterial mats.This research has been partially funded by the Spain’s Recovery and Resilience Plan included in the MINECRITICAL project “Strategic critical metals for the energy transition” (C17.I7).Peer reviewe
Enrichment of thorium and rare earth elements in an acid rock drainage: a case study in the Bierzo area (León, Spain)
[EN] The construction of a highway in El Bierzo (Spain) produced large dumps of black shales (Luarca Formation) that presented high contents of pyrite. The oxidative dissolution of pyrite generated Acid Rock Drainage (ARD), characterized by sulphated acid waters with high concentration of heavy metals that contaminated La Silva stream. Anomalies in dissolved thorium (Th), uranium (U) and rare earth elements (REE) values were detected, indicating an enrichment of several orders of magnitude when compared to natural waters. High values of REE were identified in local lithology and Th enrichment in precipitates. Black shales contain phosphate detrital minerals (monazite and xenotime) rich in Th and U that are finely distributed in the rocks. In turn, these shales are rich in organic matter and pyrite, which in presence of water have given rise to oxidative processes of pyrite and the formation of acidic waters that cause corrosion and dissolution of monazite and xenotime, yielding values of U, Th and other trace elements such as REY (eg., Ce, La, Nd, Y). Furthermore, these elements can form sulphated ionic complexes (e.g. Th(SO4)2, UO2SO4 and REYSO4+) that help the mobility.This research has been partially funded by the Spain’s Recovery and Resilience Plan included in the MINECRITICAL project “Strategic critical metals for the energy transition” (C17.I7).Peer reviewe
Fe-rich mineralized microbes from hydrothermal vents at Tagoro submarine volcano, El Hierro Island (central east Atlantic)
Annual Meeting of the Geological Society of America (113º. 2017. Honolulu)Hydrothermal iron‐rich crusts have been recovered from Tagoro submarine volcano (El Hierro, Canary Islands) in the central Atlantic. A novel hydrothermal field was discovered and filmed by ROV at the summit (89-120 m depth) of the new volcano formed in 2012. Iron- and silica-rich gelatinous deposits pool over and between basanites in hornito-like structures and surrounding areas. The rocks are capped by red and yellow mm to cm thick hydrothermally derived Fe-oxyhydroxide layered crusts; micro-cracks and degasification vesicles on basanite are filled by pyrite and anhydrite. The crusts consist of ferrihydrite and minor anhydrite, with sparse pyrite at their base. The ferrihydrite has a mean particle size of 1–5 nm indicating rapid deposition. The crusts display wide variability in bulk composition between ROV sampling stations. Fe-oxyhydroxide crusts show high contents of Fe2O3 (28-58 wt%) moderate SiO2 (up to 11.3 wt%) and P2O5 (1.4-4.8 wt%). Mn (Fe/Mn >700) and combined Co, Ni and Cu contents are very low. These deposits plot in the Fe‐rich endmember of the ternary diagram of Bonatti et al. (1972) indicating a hydrothermal origin. Normalized REE patterns of samples show a negative Ce anomaly and a strongly positive Eu anomaly, suggesting rapid deposition of the iron oxyhydroxide near the hydrothermal vent. Precipitation from the hydrothermal solution was caused by mixing with seawater. Electron microprobe studies revealed mineralized microbes that include filamentous, coccoids and helical fibrils coated by Fe-rich and silica precipitates, reflecting possible bacterial oxidation of iron from the hydrothermal fluids. The rDNA analysis indicates the abundance of Fe2+-oxidizing and sulfur- reducing and oxidizing bacteria commonly found at deep-sea hydrothermal vents. Preservation of the microbes indicates rapid mineralization with a stable supply of supersaturated fluids to the microbe surface nucleation sites. The mineralization styles evident in the microbes are similar to other mineralized microbes found in marine and terrestrial hot spring deposits in the deep Atlantic Ocean, Iceland and Yellowstone. The hydrothermal system formed at Tagoro volcano provides an excellent opportunity to study the evolution of hydrothermal fluids and mineralization processes in a shallow-water hotspot volcano settingInstituto Geológico y Minero de España, EspañaGeorg-August-Universität Göttingen, Institute for Microbiology and Genetics, AlemaniaUnited States Geological Survey, Estados UnidosEstrutura de Missão para a Extensão da Plataforma Continental, Univerdidade de Évora, Potuga