PhD Oral Defense of Qiang Qiu: Understanding Megathrust Behaviour over the Earthquake Cycle through Inversion of Geodetic Data and Dynamic Modeling
- Oral Defense
About the Event:
I here present three studies that depict megathrust behaviour over different time periods of the seismic cycle. First, I present a study on how the local morphology of a fault can control the extent of seismic rupture, and how these morphological bounds can modify the rupture dynamics within a seismic cycle. Second, I investigate postseismic deformation following recent large earthquakes of the Sumatra subduction zone to probe the rheology of the mantle wedge flow. Lastly, I examine the spatial and temporal afterslip of the 2005 Mw 8.6 Nias-Simeulue earthquake, using joint inversion of long GPS time series for both afterslip and viscoelastic processes. I assess the spatial distribution of the afterslip relative to an updated coseismic slip distribution for this event. My results are important for understanding seismic and tsunami hazard on megathrusts; they help to understand why fully locked patches sometimes rupture only partially, and the relative contributions of coseismic slip and afterslip in relieving fault stress.
Members of the Examination Committee:
- Prof. Paul Segall (External Examiner), Department of Geophysics, Stanford University, Stanford, California, USA
- Asst. Prof. Rebecca Bendick (External Examiner), Department of Geosciences, University of Montana, Missoula, Montana, USA
- Asst. Prof. Shengji Wei (Internal Examiner), Earth Observatory of Singapore and Asian School of the Environment, Nanyang Technological University, Singapore
- Assoc. Prof. Fidel Costa (Chair), Earth Observatory of Singapore and Asian School of the Environment, Nanyang Technological University, Singapore
Asst. Prof. Emma Hill, Earth Observatory of Singapore and Asian School of the Environment, Nanyang Technological University, Singapore
About the Speaker:
Qiu Qiang is a PhD student in EOS with his major in tectonic geodesy. He received his Bachelors degree in Mechanics Engineering from Hunan University (Changsha, China). After working two years in a company, he then went back to Hunan University and obtained a Masters degree in Fluid Mechanics. From 2008, he worked as a Project officer at the Protective Technology Research Center of NTU. In 2009, he joined EOS as a Research Associate and began to study tsunamis and earthquake geodesy. In 2011, he embarked on a PhD program through EOS and ASE. During his PhD studies, he worked on understanding megathrust behaviours over seismic cycles through geodetic inversion and dynamic modeling, based on advice and inspiration from his adviser Emma Hill and collaborator Sylvain Barbot.