A low-velocity zone with weak reflectivity along the Nankai subduction zone

Abstract

Research Article| March 01, 2010 A low-velocity zone with weak reflectivity along the Nankai subduction zone Jin-Oh Park; Jin-Oh Park * 1Ocean Research Institute, University of Tokyo, Tokyo 164-8639, Japan2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan *E-mail: jopark@ori.u-tokyo.ac.jp. Search for other works by this author on: GSW Google Scholar Gou Fujie; Gou Fujie 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Lalith Wijerathne; Lalith Wijerathne 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Takane Hori; Takane Hori 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Shuichi Kodaira; Shuichi Kodaira 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Yoshio Fukao; Yoshio Fukao 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Gregory F. Moore; Gregory F. Moore 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan3Department of Geology and Geophysics, University of Hawaii, Honolulu, Hawaii 96822, USA Search for other works by this author on: GSW Google Scholar Nathan L. Bangs; Nathan L. Bangs 4Institute for Geophysics, University of Texas, Austin, Texas 78758-4445, USA Search for other works by this author on: GSW Google Scholar Shin'ichi Kuramoto; Shin'ichi Kuramoto 5Center for Deep Earth Exploration, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Asahiko Taira Asahiko Taira 5Center for Deep Earth Exploration, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Search for other works by this author on: GSW Google Scholar Author and Article Information Jin-Oh Park * 1Ocean Research Institute, University of Tokyo, Tokyo 164-8639, Japan2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Gou Fujie 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Lalith Wijerathne 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Takane Hori 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Shuichi Kodaira 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Yoshio Fukao 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Gregory F. Moore 2Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan3Department of Geology and Geophysics, University of Hawaii, Honolulu, Hawaii 96822, USA Nathan L. Bangs 4Institute for Geophysics, University of Texas, Austin, Texas 78758-4445, USA Shin'ichi Kuramoto 5Center for Deep Earth Exploration, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan Asahiko Taira 5Center for Deep Earth Exploration, Japan Agency for Marine-Earth Science and Technology, Yokohama 236-0001, Japan *E-mail: jopark@ori.u-tokyo.ac.jp. Publisher: Geological Society of America Received: 09 Mar 2009 Revision Received: 06 Oct 2009 Accepted: 07 Oct 2009 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (3): 283–286. https://doi.org/10.1130/G30205.1 Article history Received: 09 Mar 2009 Revision Received: 06 Oct 2009 Accepted: 07 Oct 2009 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Jin-Oh Park, Gou Fujie, Lalith Wijerathne, Takane Hori, Shuichi Kodaira, Yoshio Fukao, Gregory F. Moore, Nathan L. Bangs, Shin'ichi Kuramoto, Asahiko Taira; A low-velocity zone with weak reflectivity along the Nankai subduction zone. Geology 2010;; 38 (3): 283–286. doi: https://doi.org/10.1130/G30205.1 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 Three-dimensional seismic reflection data reveal the presence of a low seismic velocity zone (LVZ) with weak reflectivity character along the Nankai accretionary prism. This LVZ is intercalated between an upper, offscraped layer and a lower, underthrusting layer in the outer accretionary wedge. Wide-angle ocean bottom seismograph data also support the presence of the LVZ, which is estimated to be a maximum of ∼2 km thick, ∼15 km wide, and ∼120 km long. The LVZ could be an underthrust package underplated in response to the lateral growth of the Nankai accretionary prism. Underplating of the underthrusting layer beneath the overlying offscraped layer would maintain a critical taper of the accretionary prism so that the offscraped layer can continue to grow seaward. The LVZ could have elevated fluid pressure, leading to rigidity reduction of the entire outer accretionary wedge. The rigidity-lowered outer wedge, containing the LVZ, may be more easily uplifted and thus eventually foster tsunami generation during a Nankai megathrust earthquake. If the fluid-rich LVZ supplies a significant amount of the fluid to the megasplay fault zone at depth, it may affect stick-slip behavior of the fault. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.