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  • 1
    Online Resource
    Online Resource
    Automated static and moveout corrections of high‐resolution seismic data from the Baltic Sea
    Wiley ; 2020
    In:  Near Surface Geophysics Vol. 18, No. 1 ( 2020-02), p. 23-37
    Details
    In: Near Surface Geophysics, Wiley, Vol. 18, No. 1 ( 2020-02), p. 23-37
    Abstract: High‐frequency multichannel seismic systems provide detailed images of the shallow marine subsurface. In order to exploit the redundancy inherent in such data optimally, traveltime corrections need to account for normal moveout and static effects due to vertical source and receiver variations. Misalignment of reflections in common‐midpoint gathers will significantly lower the frequency content in the final stack, making this correction particularly important for very high‐frequency seismic data. Traditionally, normal moveout correction involves labour‐intensive picking of stacking velocities, while static corrections can be, by some techniques, performed automatically. In this paper, we present a high‐frequency seismic case study from the Baltic Sea, using seismic image matching as a novel, fully automated technique to perform joint moveout and static corrections. Our multichannel test profiles were acquired offshore Rügen island for wind farm development. Owing to the regular passage of up to 1.5 m high ocean waves during data acquisition, these boomer profiles suffer from strong static effects. We perform joint normal moveout and static corrections by defining the nearest common offset section as a fixed reference frame and minimizing its difference in traveltime with respect to all available common offset sections. Time shifts are computed independent of a pre‐defined traveltime curve, using the normalized cross‐correlation as a measure of data similarity while penalizing irregular displacements by a regularization term. Time shifts are converted to stacking velocities based on the traditional hyperbolic traveltime equation. Our results are compared with those derived by conventional manual velocity analysis and subsequent trim static corrections. We find that image matching produces stacks of similar quality and stacking velocity models of similar to slightly better quality compared with the conventionally derived ones, revealing the potential of this technique to automatize and significantly speed up this first part of the seismic processing chain.
    Type of Medium: Online Resource
    ISSN: 1569-4445 , 1873-0604
    URL: Issue
    URL: Article
    DOI: 10.1002/nsg.v18.1
    DOI: 10.1002/nsg.12068
    Language: English
    Publisher: Wiley
    Publication Date: 2020
    detail.hit.zdb_id: 2247665-9
    SSG: 16,13
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  • 2
    Online Resource
    Online Resource
    The collection, digitisation, interpretation and publication of geological data in the German site selection procedure – status and challenges
    Copernicus GmbH ; 2023
    In:  Safety of Nuclear Waste Disposal Vol. 2 ( 2023-09-06), p. 141-141
    Details
    In: Safety of Nuclear Waste Disposal, Copernicus GmbH, Vol. 2 ( 2023-09-06), p. 141-141
    Abstract: Abstract. The German site selection procedure for a repository site for high-level nuclear waste is subdivided into three major phases. During the first phase, the subsurface of Germany is evaluated based on existing data, with the aim of defining siting regions for surface-based underground exploration. Although Germany is covered by large amounts of geoscientific data – including ca. 50 000 boreholes deeper than 300 m and more than 340 000 km of reflection seismic lines – the legal obligation to make these data publicly available on a national scale is fairly new and dates back to the Geological Data Act of 2020 (GeolDG: Geologiedatengesetz vom 19. Juni 2020; BGBl. I S. 1387). However, significant amounts of data are available in analogue form only, posing a significant challenge to the timeline of the site selection procedure. As the German nuclear waste management organisation, the Federal Company for Radioactive Waste Disposal (BGE) is in charge of collecting, interpreting and publishing geoscientific data that are relevant to the decisions made within the site selection procedure. In this contribution, we outline the path of data within the first phase of the site selection procedure. We start with an overview of the BGE's current and past activities related to data collection and digitisation, focussing on a major campaign through which more than 16 000 drilling reports are being digitised in cooperation with the State Office for Mining, Energy and Geology in Lower Saxony (LBEG). We then report on the different approaches of data quality control, processing and supply, highlighting challenges related to the federal organisation of geodata storage in Germany. We present selected examples of how data are used for evaluating the subsurface in terms of suitability as a potential repository site. Finally, we give an outlook of how data could be integrated into a web application that is currently being developed as an interactive tool for the public presentation of results and underlying decisions.
    Type of Medium: Online Resource
    ISSN: 2749-4802
    URL: Article
    DOI: 10.5194/sand-2-141-2023
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2023
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  • 3
    Online Resource
    Online Resource
    An integrated modeling scheme for characterizing 3D hydrogeological heterogeneity of the New Jersey shelf
    Springer Science and Business Media LLC ; 2022
    In:  Marine Geophysical Research Vol. 43, No. 2 ( 2022-06)
    Details
    In: Marine Geophysical Research, Springer Science and Business Media LLC, Vol. 43, No. 2 ( 2022-06)
    Abstract: Continental shelves around the globe are hosts to vast reservoirs of offshore freshened groundwater. These systems show considerable complexity, often as a function of the geological heterogeneity. Data needed to characterise these systems are often sparse, and numerical models rely on generalized simplifications of the geological environment. In order to improve our understanding of these systems, it is necessary to implement modelling approaches that can produce large-scale geologically representative models using sparse data. We present an interdisciplinary stochastic modelling workflow incorporating borehole data, 2D depth-migrated seismic profiles, seismic attributes, and prior knowledge of the depositional setting. We generate a conditioned Gaussian field of porosity on the New Jersey shelf. We also perform a petrophysical conversion to a corresponding permeability distribution. The model dimensions are 134 km × 69 km × 1.7 km, with an adjustable resolution that can be adapted for process-based models of flow and solute transport. The integrated approach successfully translates small-scale porosity variations to a shelf-scale model that honors key characteristics of the New Jersey shelf wave-dominated depositional environment. The model was generated using open-source packages. All data and code to reproduce the complete workflow are provided along with this study so the model can be reproduced at any resolution for further studies of continental shelf processes offshore New Jersey.
    Type of Medium: Online Resource
    ISSN: 0025-3235 , 1573-0581
    URL: Article
    DOI: 10.1007/s11001-022-09475-z
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 414196-9
    detail.hit.zdb_id: 1478200-5
    SSG: 16,13
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  • 4
    Online Resource
    Online Resource
    Geoscientific Characterization and Interpretation (Geosynthesis) within the Preliminary Safety Assessment in the German Site-Selection Procedure for a High-level Nuclear Waste Repository
    Copernicus GmbH ; 2021
    In:  Safety of Nuclear Waste Disposal Vol. 1 ( 2021-11-10), p. 45-46
    Details
    In: Safety of Nuclear Waste Disposal, Copernicus GmbH, Vol. 1 ( 2021-11-10), p. 45-46
    Abstract: Abstract. After implementation of the Repository Site Selection Act (StandAG) in 2017, the Federal Company for Radioactive Waste Disposal (BGE), as the German waste management organization, started the site selection procedure for a nuclear repository for high-level radioactive waste in Germany. On the way towards the repository site with the best possible safety, the site selection procedure is required to be a participatory, transparent, learning and self-questioning process based on scientific expertise. With the Subareas Interim Report published in 2020, first results were presented outlining subareas with favourable geological conditions in preparation for defining the siting regions for surface exploration. Currently, one of the main tasks in the site selection procedure is to establish a detailed geoscientific synthesis (Geosynthesis) for each subarea. The Geosynthesis contains all geological information for the characterization of each subarea and hence serves as the foundation for the subsequent analysis within the representative preliminary safety assessments (rvSU) and the geoscientific consideration criteria. Based on this information, all areas within the subareas will be evaluated to find the siting regions for surface exploration. The Geosynthesis includes a description of the regional geology focusing on the host rock, the overburden and relevant geological processes that may affect the potential nuclear waste repository in the next 1 million years. The data for the Geosynthesis are mostly compiled from state authorities and include 3-D geologic models, regional maps and cross-sections, bore hole data (e.g. geophysical logs) and seismic data. Furthermore, it is necessary to digitize, process, interpret and evaluate the aforementioned data using the available knowledge from the scientific literature in the context of the site selection procedure.
    Type of Medium: Online Resource
    ISSN: 2749-4802
    URL: Article
    URL: Article
    DOI: 10.5194/sand-1-45-2021
    DOI: 10.5194/sand-1-45-2021-supplement
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2021
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