Sökning: "Roland Roberts"
Visar resultat 11 - 15 av 16 avhandlingar innehållade orden Roland Roberts.
11. Physics of Aftershocks in the South Iceland Seismic Zone : Insights into the earthquake process from statistics and numerical modelling of aftershock sequences
Sammanfattning : In seismology, an important goal is to attain a better understanding of the earthquake process. In this study of the physics of aftershock generation, I couple statistical analysis with modelling of physical processes in the postseismic period. LÄS MER
12. The Potential of b-value Variations as Earthquake Precursors for Small and Large Events
Sammanfattning : The potential of variations of b-values in the G-R relation, logN=a-bM as earthquake precursors for small events (rockbursts) in Zinkgruvan mine, Sweden and for tectonic (large) earthquakes in the Andaman-Sumatra region were investigated. The temporal frequency-magnitude distribution, b(t), of rockbursts in Zinkgruvan mine was examined using high quality data recorded during the period November 1996 to April 2004 with magnitude ranges from Mw= -2. LÄS MER
13. 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
14. Analyses and Application of Ambient Seismic Noise in Sweden : Source, Interferometry, Tomography
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
15. 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
