Sökning: "seismic signals"
Visar resultat 11 - 15 av 16 avhandlingar innehållade orden seismic signals.
11. Investigating Time-Varying Processes Using Seismicity and Time-Dependent Tomography
Sammanfattning : Our global society is affected by, and makes use of, many time-varying processes. Processes related to geothermal energy and CO2 sequestration can help mitigate climate change and reduce the number of premature deaths (millions annually) due to air pollution from fossil fuels. LÄS MER
12. Analyses of Seismic Wave Conversion in the Crust and Upper Mantle beneath the Baltic Shield
Sammanfattning : Teleseismic data recorded by broad-band seismic stations in the Swedish National Seismic Network (SNSN) have been used in a suite of studies of seismic wave conversion in order to assess the structure of the crust and upper mantle beneath the Baltic Shield. Signals of seismic waves converted between P and S at seismic discontinuities within the Earth carry information on the velocity contrast at the converting interface, on the depth of conversion and on P and S velocities above this depth. LÄS MER
13. Toward fully automatic earthquake detection and processing for tomography in the Hengill area
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
14. Natural and Controlled Source Magnetotelluric Data Processing and Modeling
Sammanfattning : In this thesis, four studies using different geophysical electromagnetic methods are presented. In the first study dealing with airborne measurements, the noise response due to the rotation of the aircraft and the aircraft itself as a metallic conductive body on the Earth's electromagnetic response in very low frequency and low frequency band was investigated. LÄS MER
15. Studies of Unusual Seismicity and Long Period Events at the Glacier Overlain Katla Volcano, Iceland
Sammanfattning : Earthquake catalogues are usually dominated by diffusive behaviour consistent with the Omori law of aftershocks. This is investigated in terms of waiting times, i.e. the time between successive events in a time-sorted earthquake catalogue. LÄS MER
