Thesis (Access Restricted)
Master of Science
Several groups of earthquake clusters were selected and relocated using the JHD method. Systematic horizontal and vertical hypocentral shifts were observed. An initial 3-D Vp and Vs model was implemented by modifying the original 1-D model to include the JHD station correction patterns obtained from the previous stage. The 3-D Vp and Vs velocity structures of the study region were investigated using selected data from two years’ catalog. Perturbations in the shallow part of the velocity model become larger mainly because of the inclusion of JHD station corrections in the initial model. All events in the selected catalog were relocated using the resultant 3-D model. Hypocentral shifts are in general very small compared to the dimensions of existing active faults in the Northeastern Japan, which means that the original catalog is surprisingly accurate even if a 1-D model was used for routine earthquake locations. Previous conclusions about on-going active tectonic processes would not change.
Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Geng, Yu, "Impact of Lateral Variations of Topography and Near-Surface Geology on Earthquake Locations and Shallow Structural Images in Northern Honshu, Japan" (2017). Electronic Theses and Dissertations. 2258.