Sökning: "VLF"

Visar resultat 6 - 10 av 16 avhandlingar innehållade ordet VLF.

  1. 6. Inversion of Magnetotelluric Data Constrained by Borehole Logs and Reflection Seismic Sections

    Författare :Ping Yan; Thomas Kalscheuer; Laust Pedersen; Maria Garcia Juanatey; Andreas Junge; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetotellurics; constrained inversion; borehole logs; seismic; COSC; Alnö alkaline and carbonatite; airborne VLF; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : This thesis presents two new algorithms for doing constrained Magnetotelluric (MT) inversion based on an existing Occam 2D inversion program. The first algorithm includes borehole resistivity logs as prior information to constrain resistivity directly in the vicinity of boreholes. LÄS MER

  3. 7. Investigation of the correlation of fracture frequency and electric resistivity in impact craters in crystalline rocks

    Författare :Ann Bäckström; KTH; []
    Nyckelord :Electric resistivity; Fracture frequency; Impact generated fractures; Electro-magnetic techniques; VLF-R method; MT method; Window-mapping technique; Three-dimensional fracture calculations; heat-exchange structure; geothermal energy;

    Sammanfattning : Impact craters are formed when a large meteorite or comethits the Earth. At the impact a shock wave is released causingabundant fracturing in the surrounding bedrock. This type offracturing is intense and occurs throughout a very large volume(>100 km3) of the bedrock. LÄS MER

  4. 8. An investigation of the topographic effect and a comparison of staked an insulated receiver antennas in the VLF method

    Författare :Lena Persson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : .... LÄS MER

  5. 9. Scattering of electromagnetic waves by a perfectly conducting half plane below a stratified overburden and applications to geophysical prospecting by VLF

    Författare :Olle Olsson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : The present paper is an introduction to and a summary of a thesis consisting of the following papers:1. Scattering of electromagnetic waves by a perfectly conducting half plane below a stratified overburden. Radio Sci. (1978), Vol. LÄS MER

  7. 10. Two topics in electromagnetic radiation field prospecting

    Författare :Bruno Nilsson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : Different kinds of electrical methods have been used for a considerable time in the field of Applied Geophysics. In common these methods have almost exclusively been based on stationary or slow-varying electromagnetic fields. LÄS MER