Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

H (Human Geosciences) » H-DS Disaster geosciences

[H-DS10] Tsunami and Tsunami Forecast

Thu. May 24, 2018 9:00 AM - 10:30 AM 105 (1F International Conference Hall, Makuhari Messe)

convener:Naotaka YAMAMOTO CHIKASADA(National Research Institute for Earth Science and Disaster Resilience), Kentaro Imai(Japan Agency for Marine-Earth Science and Technology), Hiroaki Tsushima(気象庁気象研究所), Chairperson:Tanioka Yuichiro(Hokkaido University, Institute of Seismology and Volcanology), Yamamoto Naotaka(National Res. Inst. for Earth Science and Disaster Resilience)

10:15 AM - 10:30 AM

[HDS10-12] The bathymetry data development in the coastal zone, it is an object of the urgent in tsunami disaster

*Tsuyoshi Haraguchi1, Daisuke Sugawara2 (1.Department of Geosciences,Graduate School of Science,Osaka City University, 2.Museum of Natural and Environmental History, Shizuoka)

Keywords:bathymetry data, coastal zone, tsunami disaster

2011 Tohoku tsunami struck the Tohoku region coast facing the Pacific Ocean. There was no big difference in the tsunami height recorded in the offshore GPS wave meter, but a clear difference appeared in each tsunami height that struck the coast. As the tsunami gets close to the coast, the height changes suddenly.
Although the tsunami is a huge disaster, its information is extremely low because it is of low frequency. It is a powerful means of estimating tsunami by numerical calculation to compensate for it. Since the progress, concentration, and dispersion of the tsunami depends on the topography of the ocean floor, it is important for the calculation that the topography accuracy is guaranteed.
As an example of the difference in the amplification characteristics of the tsunami due to the difference in the topography of the ocean floor, the examination results of the Sanriku coast at the 2011 Tohoku Tsunami are shown. Kesennuma Bay and Hirota Bay are adjacent bays. However, the height of Rikuzentakata city tsunami reached nearly three times that of Kesennuma city area. This is the effect of the ocean bottom topography. Tsunami simulations have been conducted throughout the country, and the results are announced. However, the topographical data of the sea area, which is the basis of the calculation, has extremely small amount of information compared to the land area. Maintaining topographical data of coastal waters at the national level is a matter of focus for tsunami disaster prevention.