At 14:46 local time on 11 March 2011, a magnitude 9.0 earthquake occurred off the coast of northeast Japan. The very large local tsunami heights and damage to coastal structures and other civil infrastructure were strongly dependent on the location. To verify the effectiveness of several types of tsunami protection strategies, we analyzed three typical areas from the Sanriku ria coast. Detailed survey data are shown with photographs and are discussed with regard to severity of damage and tsunami event. The roles of offshore tsunami breakwaters and coastal forests are discussed for severe tsunami, which exceeds 10 m near the coast. The survey observations and results from numerical calculations clearly indicate the reduction of tsunami damage due to an offshore barrier in Kamaishi Bay.
Get full access to this article
View all access options for this article.
References
1.
The 2011 Tohoku Earthquake Tsunami Joint Survey Group, 2011. Nationwide field survey of the 2011 Off the Pacific Coast of Tohoku Earthquake and Tsunami, Journal of Japan Society of Civil Engineers, Series B, 67, 63–66.
2.
AkiyamaM., FrangopolD. M., SraiM., and KoshimuraS., 2013. Reliability of bridges under tsunami hazards: Emphasis on the 2011 Tohoku-oki earthquake, Earthquake Spectra29, S295–S314.
3.
ChockG., CardenL., RobertsonI., OlsenM., and YuG., 2013. Tohoku tsunami-induced building failure analysis with implications for U.S. tsunami and seismic design codes, Earthquake Spectra29, S99–S126.
4.
FoytongP., RuangrassameeA., ShojiG., HirakiY., and EzuraY., 2013. Analysis of tsunami flow velocities during the March 2011 Tohoku, Japan, tsunami, Earthquake Spectra29, S161–S181.
5.
FritzH. M., PhillipsD. A., OkayasuA., ShimozonoT., LiuH., MohammedF., SkanavisV., SynolakisC. E., and TakahashiT., 2011. 2011 Japan tsunami current velocity measurements-from survivor videos at Kesennuma Bay using LiDAR, Geophysical Research Letters39, L00G23, doi: 10.1029/2011GL050686.
6.
GokonH., and KoshimuraS., 2012. Mapping of building damage of the 2011 Tohoku earthquake and tsunami in Miyagi Prefecture, Coastal Engineering Journal54, 1250006, 12 pp.
7.
The Headquarters for Earthquake Research Promotion, 2005. National Seismic Hazard Maps for Japan, 158 pp.
8.
HoshinoD., 2012. Coastal forest in Iwate coast by Tohoku earthquake and tsunami and related damage to villages, Journal of the Japanese Forest Society, 5 pp., in press (in Japanese).
9.
LiuW., YamazakiF., GokonH., and KoshimuraS., 2013. Extraction of tsunami-flooded areas and damaged buildings in the 2011 Tohoku-oki earthquake from Terra SAR-X intensity images, Earthquake Spectra29, S183–S200.
10.
KajitaniY., ChangS. E., and TatanoH., 2013. Economic impacts of the 2011 Tohoku-oki earthquake and tsunami, Earthquake Spectra29, S457–S478.
11.
KakinumaT., TsujimotoG., YasudaT., and TamadaT., 2012. Trace survey results of the 2011 Tohoku earthquake and tsunami in the north of Miyagi Prefecture and numerical simulation of bidirectional tsunamis in Utatsusaki peninsula, Coastal Engineering Journal54, 1250007, 28 pp.
12.
KawaiH., SatohM., KawaguchiK., and SekiK., 2011. Characteristics of the 2011 off the Pacific Coast of Tohoku earthquake and tsunami, Report of the Port and Airport Research Institute50, 1–64 (in Japanese).
13.
MaseH., KimuraY., YamakawaY., YasudaT., MoriN., and CoxD. T., 2013. Were coastal defensive structures completely broken by an unexpectedly large tsunami? A field survey, Earthquake Spectra29, S145–S160.
14.
MoriN., TakahashiT., YasudaT., and YanagisawaH., 2011. Survey of 2011 Tohoku earthquake tsunami inundation and run-up, Geophysical Research Letters, doi:10.1029/2011GL049210.
15.
MoriN., and TakahashiT.The 2011 Tohoku Earthquake Tsunami Joint Survey Group, 2012. Nationwide post event survey and analysis of the 2011 Tohoku earthquake and tsunami, Coastal Engineering Journal54, 1250001, 27 pp.
OgasawaraT., MatsubayashiY., SakaiS., and YasudaT., 2012. Characteristics of the 2011 Tohoku earthquake and tsunami and its impact on the northern Iwate coast, Coastal Engineering Journal54, 1250003, 16 pp.
18.
ShimozonoT., SatoS., OkayasuA., TajimaY., FritzH. M., LiuH., and TakagawaT., 2012. Propagation and inundation characteristics of the 2011 Tohoku tsunami on the central Sanriku coast, Coastal Engineering Journal54, 1250004, 17 pp.
19.
StewartJ. P., MidorikawaS., GravesR. W., KhodaverdiK., KishidaT., MiuraH., Bozorgnia, and CampbellK. W., 2013. Implications of the Mw9.0 Tohoku-oki earthquake ground motion scaling with source, path, and site parameters, Earthquake Spectra29, S1–S21.
20.
SuppasriA. M., KoshimuraS., ImaiK., HaradaK., and ImamuraF., 2012. Developing tsunami fragility curves from the surveyed data of the 2011 Great East Japan tsunami in Sendai and Ishinomaki Plains, Coastal Engineering Journal54, 1250005, 30 pp.
21.
YoneyamaN., MoriN., and MiwaM., 2012. Numerical analysis of the 2011 off the Pacific Coast of Tohoku Earthquake Tsunami in Kamaishi Bay, Journal of the Japan Society of Civil Engineers, 5 pp., in press (in Japanese).
