Date of Award
Doctor of Philosophy
First, we developed an earthquake location technique using a non-iterative GPS location algorithm known as the Bancroft algorithm. We also proposed the use of an improved quality factor for earthquake hypocenter solutions. This factor is derived from GPS and known as geometric dilution of precision (GDOP). We applied the Bancroft algorithm to ~10 years of earthquake data in the Charlevoix Seismic zone, Canada and found that this location algorithm improves the solutions of hypocenters located in regions with high GDOP. Second, we applied and tested an interpolation technique, called least squares collocation (LSC), to the co-seismic deformation (obtained using GPS) produced by the 2010 Mw 8.8 Maule earthquake. We found that this interpolation technique cannot be used to predict the co-seismic jumps due to the low number of available GPS sites. Third, we used the same method as before to produce a trajectory prediction model (TPM) to estimate the trajectories of passive geodetic benchmarks. This methodology proved to be very useful for engineering and surveying communities dealing with co- and post-seismic deformation in large geodetic networks after great earthquakes. The TPM for Argentina is currently being implemented by the National Geographic Institute of that country. Fourth, we studied the ionospheric response in Antarctica to acoustic waves induced by Rayleigh waves produced by two major seismic events, the 2010 Mw 8.8 Maule earthquake and the 2011 Mw 9.0 Tohoku-Oki earthquake. We found that the geometry of the geomagnetic field at the South Geomagnetic Pole and the low elevation of GPS satellites in Antarctica favor the observation of acoustic wave-plasma coupling in the ionosphere. Fifth and finally, we studied the lithospheric stress guide and far-field co-seismic deformation after a megathrust earthquake. We found that the energy transmitted to the far-field depends on the asthenospheric strength. We also studied the surface deformation as a function of slip source depth, finding that sources within the stress guide are amplified in the far-field as compared to those occurring in the crust. We suggested that the information collected by far-field GPS stations can help reveal lithospheric and asthenospheric structures.
dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Gomez, Demian D., "Regional Solid Earth and Ionospheric Responses to Subduction Earthquakes in South America" (2016). Electronic Theses and Dissertations. 1439.