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dc.contributor.authorLi, Geen_US
dc.contributor.authorLiu, Yajingen_US
dc.contributor.authorRegalla, Christineen_US
dc.contributor.authorMorell, Kristinen_US
dc.date.accessioned2018-02-08T02:48:23Z
dc.date.available2018-02-08T02:48:23Z
dc.date.issued2018-04-18
dc.identifier.citationLi, G., Liu, Y., Regalla., C, and Morell K. 2018. "Seismicity relocation and fault structure near the Leech River Fault Zone, southern Vancouver Island." Journal of Geophysical Research. Solid Earth, Volume 123, Issue 4, pp. 2841-2855. https://doi.org/10.1002/2017JB015021
dc.identifier.issn2169-9313
dc.identifier.urihttps://hdl.handle.net/2144/26907
dc.description.abstractRelatively low rates of seismicity and fault loading have made it challenging to correlate microseismicity to mapped surface faults on the forearc of southern Vancouver Island. Here we use precise relocations of microsciesmicity integrated with existing geologic data, to present the first identification of subsurface seismogenic structures associated with the Leech River fault zone (LRFZ) on southern Vancouver Island. We used HypoDD double difference relocation method to relocate 1253 earthquakes reported by the Canadian National Seismograph Network (CNSN) catalog from 1985 to 2015. Our results reveal an ~8-10 km wide, NNE-dipping zone of seismicity representing a subsurface structure along the eastern 30 km of the terrestrial LRFZ and extending 20 km farther eastward offshore, where the fault bifurcates beneath the Juan de Fuca Strait. Using a clustering analysis we identify secondary structures within the NNE-dipping fault zone, many of which are sub-vertical and exhibit right-lateral strike-slip focal mechanisms. We suggest that the arrangement of these near-vertical dextral secondary structures within a more general NE-dipping fault zone, located well beneath (10-15 km) the Leech River fault (LRF) as imaged by LITHOPROBE, may be a consequence of the reactivation of this fault system as a right-lateral structure in the crust with pre-existing NNE-dipping foliations. Our results provide the first confirmation of active terrestrial crustal faults on Vancouver Island using a relocation method. We suggest that slowly slipping active crustal faults, especially in regions with pre-existing foliations, may result in microseismicity along fracture arrays rather than along single planar structures.en_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.ispartofJournal of Geophysical Research. Solid Earth
dc.rights©2018. American Geophysical Union. All Rights Reserved.en_US
dc.subjectVictoria, British Columbiaen_US
dc.subjectLeech Riveren_US
dc.subjectCanadaen_US
dc.titleSeismicity relocation and fault structure near the Leech River Fault Zone, southern Vancouver Islanden_US
dc.typeArticleen_US
dc.identifier.doi10.1002/2017JB015021
pubs.declined2018-01-02T17:35:24.817-0500en_US
pubs.elements-sourcemanual-entryen_US
pubs.notesEmbargo: Not knownen_US
pubs.organisational-groupBoston Universityen_US
pubs.organisational-groupBoston University, College of Arts & Sciencesen_US
pubs.organisational-groupBoston University, College of Arts & Sciences, Department of Earth & Environmenten_US
pubs.publication-statusPublisheden_US


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