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ID 115005
Author
Gon, Yodai Tokushima University
Imai, Kentaro Japan Agency for Marine-Earth Science and Technology
Yamashita, Kei Tohoku University
Matsuno, Tetsuo Kobe University
Hayashi, Mitsuru Kobe University
Ichihara, Hiroshi Nagoya University
Keywords
Tsunami
Submarine landslide
Directivity
Dispersion
Nankai trough
Content Type
Journal Article
Description
Tsunamis caused by submarine landslides are not accompanied by seismic waves and thus may appear at the coast without warning. In this study, detailed bathymetric surveys with a multi-narrow beam echo sounder were used to map submarine landslides on the continental shelf near Cape Muroto, in the Nankai trough off southwestern Japan. One of the surveyed submarine landslides was selected to supply dimensions for the simulation of a submarine mass movement by a two-layer flow model in which the upper and lower layers correspond to seawater and turbidity currents, respectively. The time series of seafloor deformation during this simulated landslide was used as the boundary condition to drive a tsunami simulation. The results showed strong directivity effects during tsunami generation in which pushing-dominant (positive) tsunami waves propagated seaward, in the direction of the submarine landslide, and pulling-dominant (negative) tsunami waves propagated landward. Both types of waves were strongly modified by frequency dispersion. For pulling-dominant waves, a tsunami simulation that included dispersion (Boussinesq) terms predicted greater maximum tsunami heights than a non-dispersive tsunami simulation. To avoid underestimation of tsunami heights, we recommend including dispersion terms when modeling tsunamis caused by submarine landslides for disaster planning purposes.
Journal Title
Tectonophysics
ISSN
00401951
NCID
AA00860886
AA11539709
Publisher
Elsevier
Volume
768
Start Page
228182
Published Date
2019-08-22
Rights
© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Author
departments
Science and Technology