Sökning: "geophysics"

Visar resultat 1 - 5 av 210 avhandlingar innehållade ordet geophysics.

  1. 1. Characterization of Hydrogeological Media Using Electromagnetic Geophysics

    Författare :Niklas Linde; Laust B. Pedersen; Max A. Meju; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Hydrogeophysics; radio magnetotellurics; ground penetrating radar; electrical resistance tomography; inversion; regularization; geostatistics; electrical anisotropy; fractured rock; Geofysik; Geophysics; Geofysik;

    Sammanfattning : Radio magnetotellurics (RMT), crosshole ground penetrating radar (GPR), and crosshole electrical resistance tomography (ERT) were applied in a range of hydrogeological applications where geophysical data could improve hydrogeological characterization. A profile of RMT data collected over highly resistive granite was used to map subhorizontal fracture zones below 300m depth, as well as a steeply dipping fracture zone, which was also observed on a coinciding seismic reflection profile. LÄS MER

  3. 2. Improvement and Assessment of Two-Dimensional Resistivity Models Derived from Radiomagnetotelluric and Direct-Current Resistivity Data

    Författare :Thomas Kalscheuer; Laust B. Pedersen; Christopher Juhlin; Roland Roberts; Heinrich Brasse; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electromagnetic geophysics; radiomagnetotellurics; direct-current resistivity; displacement currents; dielectric effect; non-linearity; inversion; regularization; two-dimensional model; model variance; model resolution; data resolution; Geophysics; Geofysik;

    Sammanfattning : Two-dimensional (2-D) models of electrical resistivity are improved by jointly inverting radiomagnetotelluric (RMT) and direct-current resistivity (DCR) data or by allowing for displacement currents in the inversion of RMT data collected on highly resistive bedrock. Uniqueness and stability of the 2-D models are assessed with a model variance and resolution analysis that allows for the non-linearity of the inverse problem. LÄS MER

  4. 3. Geophysical 3D models of Paleoproterozoic Iron Oxide Apatite mineralization’s and Related Mineral Systems in Norrbotten, Sweden

    Författare :Oskar Rydman; Maxim Smirnov; Thorkild Maack Rasmussen; Tobias Bauer; Niklas Juhojuntti; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Magnetotellurics; 3D Inversion modelling; Classification; Potential fields; Mineral system; Petrophysics; mineral exploration; common earth modeling; iron oxide-apatite; Northern Norrbotten ore province; Tillämpad geofysik; Applied Geophysics;

    Sammanfattning : The Northern Norrbotten ore district hosts a multitude of Sweden’s mineral deposits including world class deposits such as the Malmberget and Kirunavaara Iron oxide apatite deposits, the Aitik Iron oxide copper gold deposit, and a multitude of smaller deposits. Northern Norrbotten has been shaped by tectonothermal events related to the evolution of the Fennoscandian Shield and is a geologically complex environment. LÄS MER

  5. 4. Controlled Source Radiomagnetotelluric (CSRMT) Applications in Environmental and Resource Exploration

    Författare :Nazli Ismail; Laust Pedersen; Bulent Tezkan; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetotelluric; radio magnetotelluric; controlled-source tensor magnetotelluric; plane wave; near surface geophysics; sediment; fracture zone; inversion; forward modelling; near field effect; two-dimensional model; three-dimensional model; resolution; Geophysics; Geofysik; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys; Hydrology; hydrologi; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : An integrated use of radio magnetotelluric (RMT) and controlled source tensor magnetotelluric (CSTMT) measurements, the so-called CSRMT method, has been employed in environmental and resource exploration studies. A number of case histories, including a groundwater investigation in glacial deposits, a study of fracture zones for geotechnical purposes and a mining exploration study of a copper deposit, are presented in this thesis in order to illustrate the usefulness and capability of the CSRMT method. LÄS MER

  7. 5. Advances in time-domain induced polarization monitoring with application on chlorinated solvents contamination : Towards scalable real-time geophysical monitoring

    Författare :Aristeidis Nivorlis; Teknisk geologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geoelectrical monitoring; Chlorinated solvents; geophysics; Electrical resistivity tomography ERT ; Contaminated soil; contamination remediation geophysics;

    Sammanfattning : Environmental pollution is a significant concern for scientists, practitioners, authorities and the society. Among the various pollutants, chlorinated solvents pose a considerable risk to our groundwater resources. LÄS MER