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dc.contributor.authorYang, Haibin
dc.date.accessioned2021-02-01T05:15:34Z
dc.date.available2021-02-01T05:15:34Z
dc.date.issued2020
dc.identifier.urihttp://hdl.handle.net/11343/258890
dc.description© 2020 Haibin Yang
dc.description.abstractThis thesis explores relationships between the structure, rheology, and rupture properties of seismogenic faulting in continental lithosphere from four different perspectives. First, I derive a scaling relationship that links the spacing between two nearly parallel strike-slip faults to the frictional strength, fault width, and lower crust viscosity for strike-slip shear zones. Based on the scaling law, I estimate a possible range of lower crust viscosity in the San Andreas Fault system (California), the Marlborough Fault Zone (New Zealand) and central Tibet (China). Second, using numerical modelling methods, I explore how lower crust rheology contrast may affect the long-term evolution of a major plate boundary fault. The case study is based on the San Andreas Fault, which is found to vary dipping angles (~50-90 degree) along strike. The moderately dipping strike-slip fault is not consistent with Anderson faulting theory. This inconsistency may be reconciled if there are lateral variations in the lower crustal rheology across the fault plane that decrease fault dip with time. Third, in addition to strike-slip faults in active tectonic settings, my study also includes reverse faults in stable cratonic regions, especially for the cratonic areas of western and southern Australia. I apply statistical methods to investigate the co-seismic slip distribution of 11 surface-rupturing earthquakes in Australian stable regions and provide a link between the shape and characteristics of co-seismic slip distributions and the geophysical properties of the host crust. Fourth, using a comprehensive geophysical survey with the co-located 13GA-EG1 and 12GA-AF3 seismic reflection profiles and magnetotelluric profiles and regional gravity and magnetic maps in the Nullarbor Plain (Australia), I find that faults initiated back to the Proterozoic could still be reactivated in a Cenozoic convergent setting, especially for those major faults cutting to deep crust. Those deep-penetrating faults at terrane boundaries could be a potential channel for fluids to pass through, and thus further weakened by the fluids, which is revealed by high-conductivity anomaly in magnetotelluric profiles. The last research chapter of this thesis addresses a technical issue in the particle-in-cell finite element method, which is widely used in geodynamic numerical modelling. As mixing materials with contrasting viscosity within one element results in stress fluctuations, I assess different smoothing methods to reduce the spurious stress in mixed-material elements.
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dc.subjectSan Andreas Fault
dc.subjectTibet
dc.subjectMarlborough Fault Zone
dc.subjectfault spacing
dc.subjectGarlock Fault
dc.subjectlower crust
dc.subjectstrain partition
dc.subjectseismic hazard
dc.subjectcratonic earthquakes
dc.subjectrupture complexity
dc.subjectcoseismic slip
dc.subjectintraplate deformation
dc.subjectNullarbor plain
dc.subjectfluids in crust
dc.subjectfault reactivativity
dc.subjectstress smoothing
dc.subjectparticle in cell
dc.subjectfinite element
dc.titleThe structure, rheology, and rupture mechanics of seismogenic faulting in continental lithosphere
dc.typePhD thesis
melbourne.affiliation.departmentSchool of Earth Sciences
melbourne.affiliation.facultyScience
melbourne.thesis.supervisornameLouis Moresi
melbourne.contributor.authorYang, Haibin
melbourne.thesis.supervisorothernameMark Quigley
melbourne.tes.fieldofresearch1370604 Geodynamics
melbourne.tes.fieldofresearch2370511 Structural geology and tectonics
melbourne.accessrightsOpen Access


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