Lithospheric Dynamics of Earth's Subduction Zones and Martian Tectonic Provinces
Min Ding, Ph.D., 2015
Jian Lin, Advisor
This thesis investigates lithospheric dynamics of Earth’s subduction zones and Martian tectonic provinces on multiple time scales. In Chapter 2, I use geodetic observations to constrain the post-seismic viscoelastic deformation following the 1960 M9.5 Valdivia, Chile earthquake and quantify its stressing onto the 2010 M8.8 Maule, Chile earthquake. Analysis reveals that the post-1960 viscoelastic process might contribute to the triggering of the 2010 earthquake. Chapter 3 presents numerical experiments to investigate elastoplastic deformation and faulting in the overriding plates of subduction zones caused by the movement of subducted seamounts. Numerical simulations show that normal faults first appear on the seaward side of a subducted seamount, followed by thrust faults on the landward side of the seamount. In Chapter 4, I use the latest Martian gravity and topography data to constrain spatial variations in lithospheric flexure for various tectonic regions on Mars. The effective lithospheric thickness is estimated to be relatively small for the plain regions in southern highlands, but relatively large for the impact basins in northern lowlands as well as for the volcanic montes in the Tharis province. The regional variations in the estimated effective lithospheric thickness might reflect spatial and temporal changes in the thermal state of Mars.