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Using Space Geodesy to Constrain Variations in Seismogenic Behavior on Subduction Megathrusts

Citation

Lin, Yunung Nina (2013) Using Space Geodesy to Constrain Variations in Seismogenic Behavior on Subduction Megathrusts. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/0V1J-T074. http://resolver.caltech.edu/CaltechTHESIS:06042013-203949761

Abstract

The concept of seismogenic asperities and aseismic barriers has become a useful paradigm within which to understand the seismogenic behavior of major faults. Since asperities and barriers can be thought of as defining the potential rupture area of large megathrust earthquakes, it is thus important to identify their respective spatial extents, constrain their temporal longevity, and to develop a physical understanding for their behavior. Space geodesy is making critical contributions to the identification of slip asperities and barriers but progress in many geographical regions depends on improving the accuracy and precision of the basic measurements. This thesis begins with technical developments aimed at improving satellite radar interferometric measurements of ground deformation whereby we introduce an empirical correction algorithm for unwanted effects due to interferometric path delays that are due to spatially and temporally variable radar wave propagation speeds in the atmosphere. In chapter 2, I combine geodetic datasets with complementary spatio-temporal resolutions to improve our understanding of the spatial distribution of crustal deformation sources and their associated temporal evolution – here we use observations from Long Valley Caldera (California) as our test bed. In the third chapter I apply the tools developed in the first two chapters to analyze postseismic deformation associated with the 2010 Mw=8.8 Maule (Chile) earthquake. The result delimits patches where afterslip occurs, explores their relationship to coseismic rupture, quantifies frictional properties associated with inferred patches of afterslip, and discusses the relationship of asperities and barriers to long-term topography. The final chapter investigates interseismic deformation of the eastern Makran subduction zone by using satellite radar interferometry only, and demonstrates that with state-of-art techniques it is possible to quantify tectonic signals with small amplitude and long wavelength. Portions of the eastern Makran for which we estimate low fault coupling correspond to areas where bathymetric features on the downgoing plate are presently subducting, whereas the region of the 1945 M=8.1 earthquake appears to be more highly coupled.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:space geodesy, megathrust seismogenic behavior
Degree Grantor:California Institute of Technology
Division:Geological and Planetary Sciences
Major Option:Geology
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Simons, Mark (advisor)
  • Avouac, Jean-Philippe (advisor)
Thesis Committee:
  • Stock, Joann M. (chair)
  • Simons, Mark
  • Avouac, Jean-Philippe
  • Ampuero, Jean-Paul
Defense Date:31 May 2013
Non-Caltech Author Email:ninalin0624 (AT) gmail.com
Funders:
Funding AgencyGrant Number
Gordon and Betty Moore FoundationGBMF #423.01
National Science FoundationNNX09AD25G
National Science FoundationANR05CATT014
Record Number:CaltechTHESIS:06042013-203949761
Persistent URL:http://resolver.caltech.edu/CaltechTHESIS:06042013-203949761
DOI:10.7907/0V1J-T074
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7836
Collection:CaltechTHESIS
Deposited By: Yu-Nung Lin
Deposited On:12 Jun 2013 17:50
Last Modified:26 Apr 2019 18:28

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