Advancements in seismotectonic analysis through relative moment tensor inversion
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Drolet, Doriane
issued: 2025-01-03T18:42:30Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Large earthquakes often dominate attention due to their significant impact, but the majority of seismic activity consists of smaller and more frequent earthquakes. These smaller earthquakes, when properly analyzed, can produce enormous datasets and greatly enhance ourunderstanding of Earth’s dynamic processes. Through three research projects, this thesis focuses on developing and applying methods to analyze small earthquakes (M < 4) using the relative moment tensor inversion, addressing the challenges of small seismic sources. The first project examines two significant M7.1 intraslab earthquakes in southern Alaska: the 2016 Iniskin (24/01/2016) and the 2018 Anchorage (30/11/2018) earthquakes. The study provides insights into rupture processes and stress evolution by relocating aftershocks, recovering moment tensors, and inverting for stress variation. The aftershock distribution of the Iniskin event suggests a rupture along a steeply dipping fault in the Pacific Plate, with evidence of pre-existing fault reactivation (likely an outer-rise fault) and fluid migration. The Anchorage sequence reveals complex aftershock patterns, likely due to simultaneous rupture on both nodal planes. The second project tackles the challenges of determining moment tensors for small earthquakes recorded by sparse regional networks. Building upon previous work, a simultaneous multiple-event relative moment tensor inversion scheme is developed, leveraging constraints from P-wave polarities, relative P- and S-wave amplitudes, and local magnitude estimates without requiring prior knowledge of a reference moment tensor. This method is validated with synthetic examples and applied to a seismic cluster near San Juan Island, Washington, revealing insights into the local stress regime and fluid migration from the subducting Juan de Fuca Plate. The final project focuses on the Haida Gwaii incipient subduction zone in Canada. The study uses the novel relative moment tensor inversion technique to an…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/90032
note: Advancements in Seismotectonic Analysis through Relative MomentTensor InversionbyDoriane DroletBaccalaure´at en physique, Universite´ de Sherbrooke, 2018A THESIS SUBMITTED IN PARTIAL FULFILLMENTOF THE REQUIREMENTS FOR THE DEGREE OFDoctor of PhilosophyinTHE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES(Geophysics)The University of British Columbia(Vancouver)December 2024© Doriane Drolet, 2024The following individuals certify that they have read, and recommend to the Faculty of Graduateand Postdoctoral Studies for acceptance, the thesis entitled:Advancements in Seismotectonic Analysis through Relative Moment Tensor Inversionsubmitted by Doriane Drolet in partial fulfillment of the requirements for the degree of Doctor ofPhilosophy in Geophysics.Examining Committee:Michael Bostock, Professor, Earth, Ocean and Atmospheric Sciences, UBCSupervisorSimon Peacock, Professor, Earth, Ocean and Atmospheric Sciences, UBCSupervisory Committee MemberCharles Sammis, Professor Emeriti, Earth, Ocean and Atmospheric Sciences, UBCSupervisory Committee MemberChristian Schoof, Professor, Earth, Ocean and Atmospheric Sciences, UBCUniversity ExaminerBratt Gladman, Professor, Physics and Astronomy, UBCUniversity ExaminerAbhijit Ghosh, Professor, Earth and Planetary Sciences, University of California, RiversideExternal ExamineriiAbstractLarge earthquakes often dominate attention due to their significant impact, but the majority of seis-mic activity consists of smaller and more frequent earthquakes. These smaller earthquakes, whenproperly analyzed, can produce enormous datasets and greatly enhance our understanding of Earth’sdynamic processes. Through three research projects, this thesis focuses on developing and applyingmethods to analyze small earthquakes (M < 4) using the relative moment tensor inversion, address-ing the challenges of small seismic sources.The first project examines two significant M7.1 intraslab earthquakes in southern Alaska: the2016 Iniskin (24/01/2016) and the 2018 Anch…
has type: Thesis/Dissertation
date issued: 2025-05
is shown at: 10.14288/1.0447664
language: eng
degree discipline: Geophysics
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Bostock, Michael G.
type: Text
identifier URI: http://hdl.handle.net/2429/90032