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Tracking subducted ridges through intermediate-depth seismicity in the Vanuatu subduction zone

2018; Geological Society of America; Volume: 46; Issue: 9 Linguagem: Inglês

10.1130/g45010.1

1943-2682

C. Baillard, Wayne C. Crawford, Valérie Ballu, Bernard Pelletier, E. Garaébiti,

High-pressure geophysics and materials

Research Article| July 19, 2018 Tracking subducted ridges through intermediate-depth seismicity in the Vanuatu subduction zone Christian Baillard; Christian Baillard * 1School of Oceanography, University of Washington, 1503 NE Boat Street, Seattle, Washington 98105, USA *E-mail: baillard@uw.edu Search for other works by this author on: GSW Google Scholar Wayne C. Crawford; Wayne C. Crawford 2Institut de Physique du Globe de Paris, CNRS UMR 7154, Université Paris Diderot, 1 rue Jussieu, 75238 Paris cedex 05, France Search for other works by this author on: GSW Google Scholar Valérie Ballu; Valérie Ballu 3Littoral Environnement et Sociétés (LIENSs), CNRS UMR 7266, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France Search for other works by this author on: GSW Google Scholar Bernard Pelletier; Bernard Pelletier 4Institut pour la Recherche et le Développement, Nouméa, New Caledonia Search for other works by this author on: GSW Google Scholar Esline Garaebiti Esline Garaebiti 5Geohazards Section, Vanuatu Meteorology and Geohazards Department, PMB 9054, Lini Highway Number 2, Port Vila, Vanuatu Search for other works by this author on: GSW Google Scholar Author and Article Information Christian Baillard * 1School of Oceanography, University of Washington, 1503 NE Boat Street, Seattle, Washington 98105, USA Wayne C. Crawford 2Institut de Physique du Globe de Paris, CNRS UMR 7154, Université Paris Diderot, 1 rue Jussieu, 75238 Paris cedex 05, France Valérie Ballu 3Littoral Environnement et Sociétés (LIENSs), CNRS UMR 7266, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France Bernard Pelletier 4Institut pour la Recherche et le Développement, Nouméa, New Caledonia Esline Garaebiti 5Geohazards Section, Vanuatu Meteorology and Geohazards Department, PMB 9054, Lini Highway Number 2, Port Vila, Vanuatu *E-mail: baillard@uw.edu Publisher: Geological Society of America Received: 06 Apr 2018 Revision Received: 13 Jul 2018 Accepted: 14 Jul 2018 First Online: 19 Jul 2018 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2018 Geological Society of America Geology (2018) 46 (9): 767–770. https://doi.org/10.1130/G45010.1 Article history Received: 06 Apr 2018 Revision Received: 13 Jul 2018 Accepted: 14 Jul 2018 First Online: 19 Jul 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Christian Baillard, Wayne C. Crawford, Valérie Ballu, Bernard Pelletier, Esline Garaebiti; Tracking subducted ridges through intermediate-depth seismicity in the Vanuatu subduction zone. Geology 2018;; 46 (9): 767–770. doi: https://doi.org/10.1130/G45010.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The distribution of intermediate-depth seismicity beneath the Vanuatu archipelago (South Pacific Ocean) includes several seismic clusters/alignments and gaps, including a remarkable 200 × 150 km gap beneath central Vanuatu. We show that a zone of enhanced seismicity beneath this gap corresponds to the most likely trace of the subducted D'Entrecasteaux Ridge (DER), and that another region of aligned seismicity to the south may correspond to another significant, now-disappeared ridge. We suggest that regions of aligned intermediate-depth seismicity beneath Vanuatu are traces of subducted oceanic features on the downgoing plate, probably caused by enhanced hydration beneath them prior to subduction. The seismic gap above the DER trace, previously interpreted as a tear in the slab, may instead be a region of reduced hydration due to thick/unfractured input crust, low bending of this crust before subduction, and/or greater slab residence time at shallower subducted depths, the latter two being directly related to DER collision. We propose that an uneven distribution of intermediate-depth seismicity at subduction zones may provide a window to the history and effects of subducted oceanic features. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.