Sökning: "azimuthal anisotropy"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden azimuthal anisotropy.

1. 1. A Broad View on the Interpretation of Electromagnetic Data (VLF, RMT, MT, CSTMT)

   Författare :Behrooz Oskooi; Laust Börsting Pedersen; Thorkild Mack Rasmussen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Airborne; azimuthal anisotropy; CSTMT; distortion; EM; geothermal; Hengill; mineralization; MT; peaker; resolution; RMT; tipper; tensor VLF; VLF; Geofysik; Geophysics; Geofysik;

   Sammanfattning : The resolution power of single Very Low Frequency (VLF) data and multi-frequency Radiomagnetotelluric (RMT) data in delineating conductive structures typical for the sedimentary cover and crystalline basement in Scandinavia is studied with a view to future developments of the technique to increasing the frequency range into the LW radio band. Airborne and ground VLF data are interpreted and correlated with RMT measurements made on the ground to better understand the resolution power of VLF data. LÄS MER

3. 2. Controlled-source tensor magnetotellurics and its application to the detection of azimuthal anisotropy in the earth's crust

   Författare :Xiaobo Li; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : .... LÄS MER

4. 3. 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

5. 4. Analyses and Application of Ambient Seismic Noise in Sweden : Source, Interferometry, Tomography

   Författare :Hamzeh Sadeghisorkhani; Ólafur Gudmundsson; Ari Tryggvason; Roland Roberts; Frederik Tilmann; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Seismic interferometry; Ambient noise; Surface wave; Wave propagation; Inverse theory; Sweden; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

   Sammanfattning : Ambient seismic noise from generation to its application for determination of sub-surface velocity structures is analyzed using continuous data recordings from the Swedish National Seismic Network (SNSN). The fundamental aim of the thesis is to investigate the applicability of precise velocity measurements from ambient noise data. LÄS MER

7. 5. VLF and ULF Waves Associated with Magnetospheric Substorms

   Författare :Andrew Collier; Lars Blomberg; James McKenzie; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Subtorms; Magnetosphere; VLF waves; ULF waves; Space physics; Rymdfysik;

   Sammanfattning : A magnetospheric substorm is manifested in a variety of phenomena observed both in space and on the ground. Two electromagnetic signatures are the Substorm Chorus Event (SCE) and Pi2 pulsations. The SCE is a Very Low Frequency (VLF) radio phenomenon observed on the ground after the onset of the substorm expansion phase. LÄS MER