Sökning: "hengill"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet hengill.

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. Toward fully automatic earthquake detection and processing for tomography in the Hengill area

   Författare :Frederic Wagner; Ari Tryggvason; Ólafur Gudmundsson; Roland Roberts; Steven Gibbons; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earthquake detection; local-earthquake tomography; Iceland; induced seismicity; geothermal activity; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

   Sammanfattning : This thesis focuses on the automation of seismic data analysis, in particular, event detection, quality assessment of detected events, and preparation of an earthquake catalogue for seismic tomography.The developed event detector uses back-propagation and stacking of a seismic trace attribute with a known velocity model to detect and locate events. LÄS MER

4. 3. Seismicity and crustal structure in Iceland

   Författare :Claudia Abril; Ólafur Gudmundsson; Vala Hjörleifsdóttir; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earthquake relocation; local earthquake tomography;

   Sammanfattning : The main goal of this Ph.D. thesis is to improve locations of earthquake hypocenters and to resolve heterogeneous crustal structure and its effects on travel times. The data and case studies are drawn from the Icelandic national SIL network and the temporary NICE project deploy-ment in the Tjörnes Fracture Zone. LÄS MER

5. 4. Earthquake Sources, the Stress Field and Seismic Hazard : A Study in Eritrea and its Surrounding

   Författare :Lijam Zemichael Hagos; Roland Roberts; Hossein Shomali; Kuvvet Atakan; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Seismic hazard; Focal mechanism; Moment tensor inversion; Stress field; Afar depression; Eritrea; Geovetenskap; Earth sciences; Geovetenskap;

   Sammanfattning : Presented in this thesis are some basic concepts and applications of seismic hazard analysis and the elements that influence the amplitude and geometric attenuation of earthquake ground motion. This thesis centers on the identification of the styles of failure, focal mechanisms, and the state of regional stress in the study area. LÄS MER

7. 5. Seismic tomography : Inversion for P- and S-wave velocities

   Författare :Ari Tryggvason; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

   Sammanfattning : Seismology is undoubtedly the most powerful method for determining the structure of the Earth below the deepest borehole. This thesis describes the, use of seismic signals from both man-made and earthquake sources to model seismic velocities within a volume of the Earth. LÄS MER