Paper:

# Development and Utilization of Real-Time Tsunami Inundation Forecast System Using S-net Data

## Shin Aoi^{*,†}, Wataru Suzuki^{*}, Naotaka Yamamoto Chikasada^{*}, Takayuki Miyoshi^{*}, Taro Arikawa^{**}, and Katsumi Seki^{**}

^{*}National Research Institute for Earth Science and Disaster Resilience

3-1 Tennodai, Tsukuba, Ibaraki 305-0006, Japan

^{†}Corresponding author

^{**}Chuo University, Tokyo, Japan

It is important to advance preparation for a tsunami disaster, one of the great concerns in Japan. Forecasting tsunami inundation is one such solution, which contributes to perceiving the danger of the tsunami, as the inundation is directly linked with the damage. Therefore, we developed a new real-time tsunami forecast system, aimed at rapidly and accurately forecasting tsunami inundation on land, based on offshore tsunami data observed by the seafloor observation network along the Japan Trench, S-net. The developed system takes a database approach. A database called a tsunami scenario bank was constructed by assuming all the possible tsunami sources affecting the target region and simulating offshore pressure data, coastal tsunami heights, and tsunami inundation. The forecast system searches for suitable tsunami scenarios whose offshore pressure data explain the observed data, based on the multi-index method. The multi-index method can evaluate the resemblance of offshore pressure data by using three indices, which are sensitive to different aspects of the pressure change distribution. When tsunami scenarios meet the criteria of the multi-index method, the system provides forecast information generated from coastal tsunami heights and tsunami inundation of the selected scenarios. A prototype system was constructed for the Pacific coastal region of Chiba prefecture as a target region and has been updated through a test operation. We also investigated the comprehensible visualization and effective disaster response using tsunami forecast information. Through workshops and tabletop exercises with local government officers using the forecast system, timelines and local disaster management plans for tsunamis were tested and revised. This led to the establishment of a standard operating procedure for tsunami disaster response through the use of tsunami observation and forecast information.

*J. Disaster Res.*, Vol.14, No.2, pp. 212-224, 2019.

- [1] W. Suzuki, S. Aoi, H. Sekiguchi, and T. Kunugi, “Rupture process of the 2011 Tohoku-Oki mega-thrust earthquake (M9.0) inverted from strong-motion data,” Geophys. Res. Lett., Vol.38, L00G16, 2011.
- [2] http://www.npa.go.jp/news/other/earthquake2011/pdf/higaijokyo_e.pdf [accessed September 3, 2018]
- [3] T. Ozaki, “Outline of the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0) –Tsunami warnings/advisories and observations–,” Earth Planets Space, Vol.63, pp. 827-830, 2011.
- [4] Y. Tsuji, K. Satake, T. Ishibe, T. Harada, A. Nishiyama, and S. Kusumoto, “Tsunami heights along the Pacific coast of northern Honshu recorded from the 2011 Tohoku and previous great earthquakes,” Pure Appl. Geophys., Vol.171, pp. 3183-3215, 2014.
- [5] T. Kanazawa, K. Uehira, M. Mochizuki, T. Shinbo, H. Fujimoto, S. Noguchi, T. Kunugi, K. Shiomi, S. Aoi, T. Matsumoto, S. Sekiguchi, and Y. Okada, “S-net project, cabled observation network for earthquakes and tsunamis,” Presented at SubOptic 2016, Dubai, April 18-21, Abstract WE2B-3, 2016.
- [6] S. Aoi, N. Yamamoto, W. Suzuki, K. Hirata, T. Kunugi, H. Nakamura, T. Kubo, T. Maeda, and S. Suzuki, “Real-time Tsunami Inundation Forecast System Using S-net Data,” Proc. 16th World Conf. Earthq. Eng., No.517, 2017.
- [7] V. V., Titov, F. I. Gonzalez, E. N. Bernard, M. C. Eble, H. O. Mofjeld, J. C. Newman, and A. J. Venturato, “Real-time tsunami forecasting: Challenges and solutions,” Nat. Hazards, Vol.35, pp. 41-58, 2005.
- [8] H. Tsushima, R. Hino, Y. Tanioka, F. Imamura, and H. Fujimoto, “Tsunami waveform inversion incorporating permanent seafloor deformation and its application to tsunami forecasting,” J. Geophys. Res., Vol.117, B03311, 2012.
- [9] N. Takahashi, K. Imai, M. Ishibashi, K. Sueki, R. Obayashi, T. Tanabe, F. Tamazawa, T. Baba, and Y. Kaneda, “Real-time Tsunami Prediction System Using DONET,” J. Disaster Res., Vol.12, No.4, pp. 766-774, 2017.
- [10] A. Musa, O. Watanabe, H. Matsuoka, H. Hokari, T. Inoue, Y. Murashima, Y. Ohta, R. Hino, S. Koshimura, and H. Kobayashi, “Real-time tsunami inundation forecast system for tsunami disaster prevention and mitigation,” J. Supercomputing, Vol.74, pp. 3093-3113, 2018.
- [11] Y. Usuda, M. Hanashima, R. Sato, and H. Sano, “Effects and Issues of Information Sharing System for Disaster Response,” J. Disaster Res., Vol.12, No.5, pp. 1002-1014, 2017.
- [12] https://www.ngdc.noaa.gov/mgg/global/ [accessed August 23, 2018]
- [13] M. Kotani, F. Imamura, and N. Shuto, “Tsunami run-up simulation and damage estimation by using geographical information system,” Proc. Coastal Eng., JSCE, Vol.45, pp. 356-360, 1998 (in Japanese).
- [14] T. Miyoshi, W. Suzuki, N. Chikasada, S. Aoi, S. Akagi, and T. Hayakawa, “Development of Tsunami Simulator TNS,” Technical Note Nat’l Res. Inst. Earth Sc. Disaster Resilience, No.427, 2019 (in Japanese).
- [15] F. Imamura, A. C. Yalciner, and A. G. Ozyurt, “Tsunami modelling manual (TUNAMI model),” 2006.
- [16] Y. Okada, “Internal deformation due to shear and tensile faults in a half-spcae,” Bull. Seismol. Soc. Am., Vol.82, pp. 1018-1040, 1992.
- [17] D. Inazu and T. Saito, “Simulation of distant tsunami propagation with a radial loading deformation effect,” Earth Planets Space, Vol.65, pp. 835-842, 2013.
- [18] T. Maeda, S. Aoi, A. Iwaki, and T. Hayakawa, “A tsunami propagation modeling based on the adaptive mesh refinement,” Proc. 16th World Conf. Earthq. Eng., Paper No.2104, 2017.
- [19] N. Chikasada, W. Suzuki, T. Miyoshi, S. Aoi, M. Nemoto, K. Oshima, H. Matsuyama, J. Takayama, T. Inoue, Y. Murata, J. Satake, Y. Abe, M. Korenaga, N. Hashimoto, and S. Akagi, “Design of Tsunami Scenario Bank for Real-time Tsunami Inundation Forecast,” Technical Note Nat’l Res. Inst. Earth Sc. Disaster Resilience, No.430, 2019 (in Japanese).
- [20] H. Fujiwara, K. Hirata, H. Nakamura, M. Osada, N. Morikawa, S. Kawai, T. Ohsumi, S. Aoi, H. Matsuyama, N. Toyama, T. Kitou, Y. Murashima, Y. Murata, T. Inoue, R. Saito, S. Akiyama, M. Korenaga, Y. Abe, and N. Hashimaoto, “An Approach to Tsunami Hazard Assesment along the Northeastern Coastal Area in Japan –Method and Preliminary Results–,” Technical Note Nat’l Res. Inst. Earth Sc. Disaster Prevention, No.400, 2015 (in Japanese).
- [21] C. J. Ammon, H. Kanamori, and T. Lay, “A great doublet and seismic stress transfer cycle in the central Kuril islands,” Nature, Vol.451, pp. 561-565, 2008.
- [22] A. Suppasri, N. Leelawat, P. Latcharote, V. Roeber, K. Yamashita, A. Hayashi, H. Ohira, K. Fukui, A. Hisamatsu, D. Nguyen, and F. Imamura, “The 2016 Fukushima earthquake and tsunami: Local tsunami behavior and recommendations for tsunami disaster risk reduction,” Int. J. Disaster Risk Reduction, Vol.21, pp. 323-330, 2017.
- [23] Y. Tanioka and K. Satake, “Fault parameters of the 1896 Sanriku tsunami earthquake estimated from tsunami numerical modeling,” Geophys. Res. Lett., Vol.23, pp. 1549-1552, 1996.
- [24] K. Kajiura, “The leading wave of a tsunami,” Bull. Earthq. Res. Inst. Univ. Tokyo, Vol.41, pp. 535-571, 1963.
- [25] T. Arikawa, K. Seki, Y. Oki, H. Hirano, Y. Chida, K. Araki, K. Ishii, T. Takagawa, and K. Shimosako, “Development of high precision tsunami runup calculation method coupled with structure analysis,” J. Japan Soc. Civil Eng. B2 (Coastal Engneering), Vol.73, pp. I_325-I_330, 2017 (in Japanese).
- [26] T. Arikawa, K. Seki, K. Shimosako, T. Takagawa, and Y. Chida, “Development of tsunami inundation evalulation method using fragility curve,” J. Japan Soc. Civil Eng. B2 (Coastal Engneering), Vol.73, pp. I_337-I_347, 2017 (in Japanese).
- [27] N. Yamamoto, S. Aoi, K. Hirata, W. Suzuki, T. Kunugi, and H. Nakamura, “Multi-index method using ofshore ocean-bottom pressure data for real-time tsunami forecast,” Earth Planets Space, Vol.68, Paper No.128, 2016.
- [28] H. Takeuchi, R. Fuji, N. Mimura, F. Imamura, K. Satake, Y. Tsuji, K. Hochi, and T. Matsuura, “Survey of run-up height of Empo Boso-oki Earthquake Tsunami on the coast from Chiba Prefecture to Fukushima Prefecture,” Rekishi-Jishin, Vol.22, pp. 53-59, 2007 (in Japanese).

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