HR: 0800h
AN: S31C-0564    [Abstracts]
TI: Designing a Geologically Satisfying Model of the 2004 Sumatra-Andaman Earthquake
AU: * Hughes, K L
EM: klhughes@bama.ua.edu
AF: University of Alabama, University of Alabama, Tuscaloosa, AL 35487, United States
AU: Masterlark, T
EM: masterlark@geo.ua.edu
AF: University of Alabama, University of Alabama, Tuscaloosa, AL 35487, United States
AB: Deformation models are simplified versions of actual geologic systems. A suitable model design reflects a balance of problem domain complexity and computational simplicity. Designing a valid conceptual model is a critical, and often overlooked, step in the modeling process and is the focus of this study of the M9+ Sumatra- Andaman earthquake of 26 December 2004. This earthquake is the largest recorded by GPS measurements, which can be used to verify the results of our model. The GPS measurements are accurate to within millimeters, so it is imperative that the model be as geologically accurate as possible. In building this model we employed the use of seismic and tomography data, geologic maps, and structure and cross-section images. The first iteration of our 3-D finite element model (FEM) was constructed using a single cross-section generated through the southern part of Sumatra. The results of this study indicated that observed GPS measurements corresponded well to the predicted GPS measurements of the FEM to the south. However, the northern observed and predicted measurements were not as consistently correlated. This could partly be due to the simplification of propagating a single cross-section along the strike of the Sunda trench. This second iteration of the FEM will merge both the southern cross-section and a northern cross-section taken through the Andaman Islands including the back-arc spreading center to the east. Merging the cross-sections will account for the changing geology and structure of the island arc from south to north, and ultimately generate more reliable deformation predictions.
DE: 0550 Model verification and validation
DE: 4255 Numerical modeling (0545, 0560)
DE: 8118 Dynamics and mechanics of faulting (8004)
DE: 8170 Subduction zone processes (1031, 3060, 3613, 8413)
SC: Seismology [S]
MN: 2007 Fall Meeting