Broad Band Modeling Earthquake Source and Upper Mantle Structure on Plate Boundary Zones

Citation

Song, Teh-Ru Alex (2008) Broad Band Modeling Earthquake Source and Upper Mantle Structure on Plate Boundary Zones. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/K7RQ-MM41. https://resolver.caltech.edu/CaltechETD:etd-05192008-121937

Abstract

Broadband seismic arrays have provided unprecedented data sets for seismologists to image the slips on faults and velocity structure beneath Earth's surface at all scales. In particular, plate boundary zones are the most complicated regions on the surface and full of complexities. Often that great earthquakes occur and rapid structural changes take place.

In my thesis, one major effort is to use geophysical data and broadband seismic data to characterize the occurrences of great earthquakes at the subduction zone interface. Using gravity data from satellite and bathymetry model ETopo5, I recognized the strong correlation between gravity, topography and the occurrences of great earthquakes. Such a correlation gives a strong indication that lateral variations in the occurrences of great earthquakes at a given subduction zone are strongly linked to the fore-arc structure and topographic features such as basin and peninsulas. I also give robust estimates of the size and rupture extent of the recent 2004 Sumatra-Andaman giant earthquake using Earth's normal modes.

Another part of my thesis consists of modeling waveform distortion and interference to study lithosphere and deep upper mantle structure. Modeling multi-pathing associated with sharp structure has become a very powerful method to delineate structure and explain the complicated behavior shown in the data recorded by dense arrays.

Future research will focus on linking geodynamic models and seismic analysis of broadband waveform data as a way to further constrain the mantle structure and validate various geodynamic models.

Thesis Files