Evolution of the Nankai Trough décollement from the trench into the seismogenic zone: Inferences from three-dimensional seismic reflection imaging

Abstract

Research Article| April 01, 2004 Evolution of the Nankai Trough décollement from the trench into the seismogenic zone: Inferences from three-dimensional seismic reflection imaging Nathan L. Bangs; Nathan L. Bangs 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Search for other works by this author on: GSW Google Scholar Thomas H. Shipley; Thomas H. Shipley 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Search for other works by this author on: GSW Google Scholar Sean P.S. Gulick; Sean P.S. Gulick 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Search for other works by this author on: GSW Google Scholar Gregory F. Moore; Gregory F. Moore 2Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Search for other works by this author on: GSW Google Scholar Shinichi Kuromoto; Shinichi Kuromoto 3Center for Deep Earth Exploration, Japan Marine Science and Technology Center, 2-15, Natshusima-cho, Yokohama, Kanagawa 237-0061, Japan Search for other works by this author on: GSW Google Scholar Yasuyuki Nakamura Yasuyuki Nakamura 4Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan Search for other works by this author on: GSW Google Scholar Author and Article Information Nathan L. Bangs 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Thomas H. Shipley 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Sean P.S. Gulick 1Institute for Geophysics, University of Texas, 4412 Spicewood Springs Road, Austin, Texas 78759, USA Gregory F. Moore 2Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA Shinichi Kuromoto 3Center for Deep Earth Exploration, Japan Marine Science and Technology Center, 2-15, Natshusima-cho, Yokohama, Kanagawa 237-0061, Japan Yasuyuki Nakamura 4Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan Publisher: Geological Society of America Received: 01 Oct 2003 Revision Received: 26 Dec 2003 Accepted: 06 Jan 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2004) 32 (4): 273–276. https://doi.org/10.1130/G20211.2 Article history Received: 01 Oct 2003 Revision Received: 26 Dec 2003 Accepted: 06 Jan 2004 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Nathan L. Bangs, Thomas H. Shipley, Sean P.S. Gulick, Gregory F. Moore, Shinichi Kuromoto, Yasuyuki Nakamura; Evolution of the Nankai Trough décollement from the trench into the seismogenic zone: Inferences from three-dimensional seismic reflection imaging. Geology 2004;; 32 (4): 273–276. doi: https://doi.org/10.1130/G20211.2 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 We mapped the amplitude of the Nankai Trough subduction thrust seismic reflection from the trench into the seismogenic zone with three-dimensional seismic reflection data. The décollement thrust forms within the lithologically homogeneous Lower Shikoku Basin facies along an initially nonreflective interface. The reflection develops from a porosity contrast between accreted and underthrust sedimentary material because of accretionary wedge consolidation and rapid loading and delayed consolidation of the underthrust section. A décollement-amplitude map shows a significant decline from high amplitudes at the trench to barely detectable levels 25–30 km landward. Three other observations coincide with the amplitude decline: (1) the décollement initially steps down to deeper stratigraphic levels, (2) the wedge taper increases dramatically, and (3) the thrust becomes seismogenic. The amplitude decline and the coincident décollement and accretionary- wedge tectonic and seismogenic behavior are attributed to the loss of fluids and potentially loss of excess fluid pressures downdip along the subduction thrust. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.