64 research outputs found

    An overview of the Upper Paleozoic-Mesozoic stratigraphy of the NE Atlantic region

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    This study describes the distribution and stratigraphic range of the Upper Paleozoic–Mesozoic succession in the NE Atlantic region, and is correlated between conjugate-margins and along the axis of the NE Atlantic rift system. The stratigraphic framework has yielded important new constraints on the timing and nature of sedimentary basin development in the NE Atlantic, with implications for rifting and the breakup of the Pangaean supercontinent. From a regional perspective, the Permian–Triassic succession records a northward transition from an arid interior to a passively-subsiding, mixed carbonate/siliciclastic shelf margin. A Late Permian–earliest Triassic rift pulse has regional expression in the stratigraphic record. A fragmentary paralic to shallow-marine Lower Jurassic succession reflects Early Jurassic thermal subsidence and mild extensional tectonism; this was interrupted by widespread Mid-Jurassic uplift and erosion, and followed by an intense phase of Late Jurassic rifting in some (but not all) parts of the NE Atlantic region. The Cretaceous succession is dominated by thick basinal-marine deposits, which accumulated within and along a broad zone of extension and subsidence between Rockall and NE Greenland. There is no evidence for a substantive and continuous rift system along the proto-NE Atlantic until the Late Cretaceous

    GlaciStore: understanding Late Cenozoic glaciation and basin processes for the development of secure large scale offshore CO2 storage (North Sea).

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    The sedimentary strata of the North Sea Basin (NSB) record the glacial and interglacial history of environmental change in the Northern Hemisphere, and are a proposed location for the engineered storage of carbon dioxide (CO2) captured from power plant and industrial sources to reduce greenhouse gas emissions. These aspects interact in the geomechanical and fluid flow domain, as ice sheet dynamics change the properties of potential seal and reservoir rocks that are the prospective geological storage strata for much of Europe’s captured CO2. The central part of the NSB preserves a unique history of the depositional record spanning at least the last 3 Ma, which also forms the overburden and uppermost seal to the underlying CO2 reservoirs. There is good evidence that these ice sheets created strong feedback loops that subsequently affected the evolution of the Quaternary climate system through complex ocean-atmosphere-cryosphere linkages

    Development of a machine learning technique for automatic analysis of seafloor image data: Case example,Pogonophora coverage at mud volcanoes

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    Digital image processing provides powerful tools for fast and precise analysis of large image data sets in marine and geoscientific applications. Because of the increasing volume of georeferenced image and video data acquired by underwater platforms such as remotely operated vehicles, means of automatic analysis of the acquired image data are required. A new and fast-developing application is the combination of video imagery and mosaicking techniques for seafloor habitat mapping. In this article we introduce an approach to fully automatic detection and quantification of Pogonophora coverage in seafloor video mosaics from mud volcanoes. The automatic recognition is based on textural image features extracted from the raw image data and classification using machine learning techniques. Classification rates of up to 98.86% were achieved on the training data. The approach was extensively validated on a data set of more than 4000 seafloor video mosaics from the Haakon Mosby Mud Volcano

    Automatic content-based analysis of georeferenced image data: detection of Beggiatoa mats in seafloor video mosaics from the HĂĄkon Mosby Mud Volcano

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    The combination of new underwater technology as Remotely Operating Vehicles (ROVs), high resolution video imagery, and software to compute georeferenced mosaics of the seafloorprovides new opportunities for marine geological or biological studies and applications in offshore industry. Even during single surveys by ROVs or towed systems large amounts of images are compiled. While these underwater techniques are now well-engineered, there is still a lack of methods for the automatic analysis of the acquired image data. During ROV dives more than 4200 georeferenced video mosaics were compiled for the HĂĄkon Mosby MudVolcano (HMMV). Mud volcanoes as HMMV are considered as significant source locations for methane characterised by unique chemoautotrophic communities as Beggiatoa mats. For the detection and quantification of the spatial distribution of Beggiatoa mats an automated image analysis technique was developed, which applies watershed transformation and relaxationbasedlabelling of pre-segemented regions. Comparison of the data derived by visual inspection of 2840 video images with the automated image analysis revealed similarities, a precisionbetter than 90%. We consider this as a step towards a time efficient and accurate analysis of seafloor images for computation of geochemical budgets and identification of habitats at theseafloor
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