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dc.contributor.authorRoland, Emily C.  Concept link
dc.coverage.spatialEast Pacific Rise
dc.date.accessioned2012-02-02T17:19:27Z
dc.date.available2012-02-02T17:19:27Z
dc.date.issued2012-02
dc.identifier.urihttps://hdl.handle.net/1912/5011
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2012en_US
dc.description.abstractOceanic transform faults that accommodate strain at mid-ocean ridge offsets represent a unique environment for studying fault mechanics. Here, I use seismic observations and models to explore how fault structure affects mechanisms of slip at oceanic transforms. Using teleseismic data, I find that seismic swarms on East Pacific Rise (EPR) transforms exhibit characteristics consistent with the rupture propagation velocity of shallow aseismic creep transients. I also develop new thermal models for the ridge-transform fault environment to estimate the spatial distribution of earthquakes at transforms. Assuming a temperature-dependent rheology, thermal models indicated that a significant amount of slip within the predicted temperature-dependent seismogenic area occurs without producing large-magnitude earthquakes. Using a set of local seismic observations, I consider how along-fault variation in the mechanical behavior may be linked to material properties and fault structure. I use wide-angle refraction data from the Gofar and Quebrada faults on the equatorial EPR to determine the seismic velocity structure, and image wide low-velocity zones at both faults. Evidence for fractured fault zone rocks throughout the crust suggests that unique friction characteristics may influence earthquake behavior. Together, earthquake observations and fault structure provide new information about the controls on fault slip at oceanic transform faults.en_US
dc.description.sponsorshipMaterial presented in this thesis is based on work supported by the National Science Foundation Division of Ocean Science (OCE) grants #0548785, #0623188, #0649103, and #0242117 and Division of Earth Sciences (EAR) grants #0814513 and #0943480. This work was also supported by the W. M. Keck Foundation and the Deep Ocean Exploration Institute.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen_US
dc.relation.ispartofseriesWHOI Thesesen_US
dc.subjectFaultsen_US
dc.subjectThermal analysisen_US
dc.titleEarthquake behavior and structure of oceanic transform faultsen_US
dc.typeThesisen_US
dc.identifier.doi10.1575/1912/5011


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