Characteristics of a tsunamigenic megasplay fault in the Nankai Trough

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doi: 10.1002/grl.50888
Author(s): Yamada, Yasuhiro; Masui, Reona; Tsuji, Takeshi
Author Affiliation(s): Primary:
Kyoto University, Department of Earth Resources Engineering, Kyoto, Japan
Volume Title: Geophysical Research Letters
Source: Geophysical Research Letters, 40(17), p.4594-4598. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276 CODEN: GPRLAJ
Note: In English. 28 refs.; illus., incl. sketch maps
Summary: Slip on the shallow part of a megasplay fault that is an out-of-sequence thrust and branch of the main subduction plate boundary can cause devastating tsunamis after earthquakes. We analyzed the three-dimensional geometry, including dip amount and azimuths, roughness distributions, and thickness variations, of the shallow part of a megasplay fault in the Nankai Trough using a three-dimensional seismic data set. The fault is divided into three zones based on its geometry: thick, smooth, and simply convex in the east; complexly curved in the middle; and thin and kinked in the west. Results of scientific drilling indicate that the eastern region of the fault is most active, and local heterogeneities in fault geometry, including roughness and thickness, may control the slip on this part of the fault. The present findings can be used to evaluate the risk of future tsunamis arising from movement on shallow thrust faults at subduction margins. Abstract Copyright (2013), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2013
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; 22 Environmental Geology; Crust; Displacements; Fault zones; Faults; Geologic hazards; IODP C0001; IODP C0002; IODP C0009; IODP C0010; Integrated Ocean Drilling Program; Lithosphere; NanTroSEIZE; Nankai Trough; Natural hazards; North Pacific; Northwest Pacific; Oceanic crust; Oceanic lithosphere; Pacific Ocean; Risk assessment; Risk management; Slip rates; Subduction zones; Tsunamis; West Pacific
Coordinates: N320000 N350000 E1380000 E1350000
Record ID: 2013091223
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom