HR: 08:20h
AN: T31G-02    [Abstracts]
TI: Coastal Deformation Sssociated with the 2007 Noto Hanto Earthquake, Central Japan, Determined by Uplifted and Subsided Intertidal Organisms
AU: * Awata, Y
EM: awata-y@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Toda, S
EM: s-toda@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Kaneda, H
EM: h-kaneda@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Azuma, T
EM: t-azuma@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Horikawa, H
EM: h.horikawa@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Shishikura, M
EM: m.shishikura@aist.go.jp
AF: Geological Survey of Japan, AIST, AIST Central-7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Echigo, T
EM: echigo@geor.or.jp
AF: Geo-Research Institute, 4-3-2, Itachibori, Osaka, 550-0012, Japan
AB: The March 25, 2007 Noto Hanto earthquake (Mj 6.9, Mw 6.7) caused a vertical crustal movement along the northwestern coast of the Noto Peninsula, central Japan. We promptly determined pattern and amount of coseismic coastal movement by using uplifted and subsided intertidal sessile organisms. Our observations show a broad 20-km-wide asymmetric surficial deformation above and across the south-dipping source fault, with steep north-facing frontal limb and gentle south-facing back limb. The maximum uplift was ~40 cm at the crest. Our forward modeling suggests that the south-dipping source fault is buried at a depth of ~2 km and that 1.2 m slip on that fault yields best fit to our surface observation. Our results show that traditional field mapping should be combined with modern instrumental observations such as GPS and InSAR for the most effective and reliable estimate of spatio-temporal crustal movement associated with large earthquakes.
DE: 1209 Tectonic deformation (6924)
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7299 General or miscellaneous
DE: 8005 Folds and folding
DE: 8123 Dynamics: seismotectonics
SC: Tectonophysics [T]
MN: 2007 Fall Meeting