41 research outputs found

    Precise OBS location at the sea bottom in active seismic profiles using the air gun shot records

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    The Norcaribe campaign, in November – December 2013, funded by Spanish Ministry of Innovation and Science (Norcaribe Project CGL2010-17715), was performed on board of the Spanish research vessel “Sarmiento de Gamboa” around the Hispaniola island, also with the participation of the Dominic Republic Navy patrol vessels and several Haiti and Dominic Republic institutions. During the campaign, a 200 km long, wide-amgle refraction seismic profile was carried out crossing the Beata ridge. The air gun signal (5100 ci) was recorded by 15 OBSs deployed along the seismic line in water depths between 2.300 meters and 4.320 meters. To obtain the section records, the OBS position is needed, usually the deployment location is used, but the OBS can drift while is sinking due to the deep oceanic currents. The recovery locations at surface could provide information about the drift, assuming a constant sea current since the deployment to the recovery, but it is imprecise. In this work we show a method to obtain a precise location of the OBS at the sea bottom using a high-resolution bathymetry and the OBS record of the closest air gun shots of the profile. Also, the preliminary results for the Norcaribe campaign (Beata ridge profile) are shown.Peer Reviewe

    Magnetic anomalies of the NW Iberian continental margin and the adjacent abyssal plains

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    The NW Iberian margin is a hyperextended continental margin, formed during the opening of the North Atlantic Ocean, where a subsequent partial tectonic inversion has undergone during the Alpine Orogeny. This succession of tectonic episodes determines the magnetic signature of the margin. The Spanish Exclusive Economic Zone Project has carried out seven one-month cruises between 2001 and 2009. To extend and densify the spatial coverage, we have used data from the World Digital Magnetic Anomaly Map. Here, we describe the methodology used for the acquisition and data processing of the magnetic field data. The use of diverse instrumentation, a non-complete external field’s cancelation, and the use of different magnetic core field models, contributed to the total error budget. To reduce it, we have used a leveling algorithm which minimizes all these contributions. Finally, a statistical analysis was applied using crossover residuals, showing a resolution better than 28 nT

    New interpretation of the sedimentary infill of the San Pedro basin based on new seismic data (Dominican Republic offshore)

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    Los nuevos datos de sísmica de reflexión multicanal 2D adquiridos en la Cuenca de San Pedro (margen sudeste de la República Dominicana), junto con antiguos perfiles sísmicos reprocesados, han permitido llevar a cabo un detallado análisis y revisión de la estratigrafía sísmica. Los nuevos datos sísmicos aportan nuevas precisiones sobre la evolución de la cuenca sugiriendo un origen de al menos Eoceno Superior, en lugar de Mioceno. La nueva interpretación se basa en la correlación onshore-offshore de un nivel guía de abanicos bien desarrollado, con los eventos tectónicos constreñidos tierra y asociados a la colisión con los Bancos de las Bahamas con el arco isla el Eoceno Medio.New 2D multichannel seismic reflection data recorded in the San Pedro Basin (south-eastern margin of Dominican Republic,) combined with vintage seismic reflection profiles, have allowed a detailed analysis and review of the seismic stratigraphy. New data supply new constraints on the evolution of the basin and suggest at least an Upper Eocene origin instead of Miocene. The new interpretation is based on the onshore-offshore correlation of fan deposits with the main tectonic events constrained onshore and related with the collision of the Bahamas banks with the island arc in Middle Eocene ages.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

    Shallower structure and active process in the northern Hispaniola offshore margin (Dominican Republic): Preliminary results

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    El margen submarino del norte de La Española registra el proceso de colisión activa entre los Bancos de las Bahamas y el arco isla. Esta colisión ha producido numerosos terremotos causando cuantiosos daños en la costa norte de la isla. La campaña NORCARIBE (2013) combinó la adquisición sistemática de datos geofísicos de todo el margen subductivo, especialmente en la zona de República Dominicana, proporcionando una información continua y de alta resolución. Esta información ha permitido estudiar con detalle la variación transversal y longitudinal del margen subductivo caracterizado por la Fosa de la Española (FE) y el Cinturón Deformado Septentrional (CDS). Este margen compresivo presenta una estructura imbricada con vergencia hacia el norte y segmentada por zonas de transferencia limitando la longitud máxima de las fallas inversas. Existen numerosas evidencias de deformación activa que deben ser consideradas en futuros estudios sobre la evaluación de la peligrosidad sísmica y tsunamigénica en la región, así como para la evaluación de recursos marinos y la ordenación del territorio de la República Dominicana.The northern Hispaniola offshore margin records the active collision between the Bahamas Banks and island arc. This collision is associated to the occurrence of numerous earthquakes that caused significant damages in the northern coast of the island. The NORCARIBE cruise carried out in 2013 combined the systematic acquisition of geophysical data in the whole collisional margin, mainly focused in Dominican Republic, providing continuous and high resolution information. This new information has allowed to study with more detail the along- and across-strike structure of the collisional margin characterized by the Hispaniola trench and the Northern Deformed Belt. This compressive margin shows a N-verging imbricate structure segmented along strike by transfer zones limiting the maximum fault length. There are numerous evidences of active deformation that have to be considered in future studies on the seismic and tsunamigenic assessment in the region, as well as for the assessment on marine resources and development planning of Dominican Republic.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Economía y Competitividad (MINECO)Universidad Complutense de Madridpu

    Stratigraphic and structural interpretation of the San Pedro Basin (south-eastern Dominican Republic offshore margin)

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    La cuenca de San Pedro (CSP) se define como una depresión batimétrica con tendencia E-O y una extensión aproximada de 6000 km2, situada en el margen sureste de la isla de La Española (República Dominicana y Haití). Estructuralmente se ubica en la parte trasera del Cinturón Deformado de los Muertos (CDM). Considerada tradicionalmente como una cuenca de edad Mioceno medio, cuyo relleno ha sido depositado en el espacio de configuración generado por la progresiva deformación del CDM. Sin embargo, gracias a la integración de los trabajos de cartografía geológica (Proyectos SYSMIN I y II) con datos de geofísica de subsuelo (sísmica de reflexión, registros de pozo y campos potenciales), ha sido posible proponer un nuevo modelo evolutivo de la cuenca que abarca desde el inicio de la sedimentación en un contexto de retro-arco desde el Cretácico Superior hasta la inversión de la cuenca en el Eoceno medio y la posterior evolución del conjunto CSP-CDM hasta la actualidad, pudiendo correlacionar las principales secuencias estratigráficas y estructuras con los datos de afloramiento y pozo.The San Pedro Basin (SPB) consists of an E-W bathymetric depression with an extension of 6000 km2, located in the south-eastern margin of Hispaniola Island (Dominican Republic and Haiti). Structurally, the SPB is situated at the rear zone of the Muertos Thrust Belt (MTB). The basin has been dated as middle Miocene in the bibliography, with the infill deposited in the configuration space generated by the progressive deformation of the MTB. Nevertheless, the integration of the new systematic geological mapping (SYSMIN I&II Programs) with geophysical data (reflection seismic, well logs and potential fields) led us to propose a new evolution model of the basin from the start of sedimentation in Upper Cretaceous in a retro-arc context to the inversion of the basin in middle Eocene and the later evolution of the SPB-MTB system until present, establishing the correlation between main sequences with outcrops and well data.Depto. de Geodinámica, Estratigrafía y PaleontologíaDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

    The chromatin accessibility landscape of primary human cancers

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    We present the genome-wide chromatin accessibility profiles of 410 tumor samples spanning 23 cancer types from The Cancer Genome Atlas (TCGA).We identify 562,709 transposase-accessible DNA elements that substantially extend the compendium of known cis-regulatory elements. Integration of ATAC-seq (the assay for transposase-accessible chromatin using sequencing) with TCGA multi-omic data identifies a large number of putative distal enhancers that distinguish molecular subtypes of cancers, uncovers specific driving transcription factors via protein-DNA footprints, and nominates long-range gene-regulatory interactions in cancer. These data reveal genetic risk loci of cancer predisposition as active DNA regulatory elements in cancer, identify gene-regulatory interactions underlying cancer immune evasion, and pinpoint noncoding mutations that drive enhancer activation and may affect patient survival. These results suggest a systematic approach to understanding the noncoding genome in cancer to advance diagnosis and therapy
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