Seismic anisotropy and microseismicity: from crustal formation to subduction termination ...

• Main Author: Bacon, Conor
• Format: Thesis
• Language: English
• Published: Apollo - University of Cambridge Repository 2021
• Subjects: seismic anisotropy; seismology; tectonics; volcano seismology; microseismicity; Iceland; Southeast Asia; Mid-Atlantic Ridge
• Online Access: https://dx.doi.org/10.17863/cam.82196; https://www.repository.cam.ac.uk/handle/1810/334765

The plate tectonic cycle is fundamental to our dynamic Earth, encompassing the formation and evolution of new lithosphere at divergent, mid-ocean ridges, all the way to its eventual return to, and re-equilibration with, the mantle in subduction zones. I investigate the structure of the crust and upper mantle of the Earth in two regions that represent different endmembers in this cycle through the analysis of microseismicity and seismic anisotropy, seeking to learn more about the stresses in these environments and how they are manifest in the structure of the subsurface. In Iceland, new oceanic crust is accreted episodically within the volcanic rift zones that delineate the subaerial portion of the Mid-Atlantic Ridge, the divergent margin between the North American and the Eurasian plates. Northern Borneo, conversely, exhibits the tectonic signatures of not one but two terminated subduction zones, where oceanic lithosphere was once being actively recycled into the Earth’s mantle. As part of this work, I have ...