Real-Time Tsunami Prediction System Using DONET
Narumi Takahashi*1,†, Kentaro Imai*2, Masanobu Ishibashi*3, Kentaro Sueki*2, Ryoko Obayashi*2, Tatsuo Tanabe*4, Fumiyasu Tamazawa*4, Toshitaka Baba*5, and Yoshiyuki Kaneda*6
*1National Research Institute for Earth Science and Disaster Resilience
3-1 Tennodai, Tsukuba 305-0006, Japan
*2Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
*3Wakayama Prefecture, Wakayama, Japan
*4NTT data CCS corporation, Tokyo, Japan
*5Tokushima University, Tokushima, Japan
*6Kagawa University, Takamatsu, Japan
We constructed a real-time tsunami prediction system using the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET). This system predicts the arrival time of a tsunami, the maximum tsunami height, and the inundation area around coastal target points by extracting the proper fault models from 1,506 models based on the principle of tsunami amplification. Since DONET2, installed in the Nankai earthquake rupture zone, was constructed in 2016, it has been used in addition to DONET1 installed in the Tonankai earthquake rupture zone; we revised the system using both DONET1 and DONET2 to improve the accuracy of tsunami prediction. We introduced a few methods to improve the prediction accuracy. One is the selection of proper fault models from the entire set of models considering the estimated direction of the hypocenter using seismic and tsunami data. Another is the dynamic selection of the proper DONET observatories: only DONET observatories located between the prediction point and tsunami source are used for prediction. Last is preparation for the linked occurrence of double tsunamis with a time-lag. We describe the real-time tsunami prediction system using DONET and its implementation for the Shikoku area.
-  M. Ando, “Source mechanisms and tectonic significance of historical earthquakes along the nankai trough,” Japan, Vol.27, No.2, pp. 119-140, http://dx.doi.org/10.1016/0040-1951(75)90102-X, 1975.
-  T. Furumura, K. Imai, and T. Maeda, “A revised tsunami source model for the 1707 Hoei earthquake and simulation of tsunami inundation of Ryujin Lake, Kyushu,” Japan. , J. Geophys. Res., Vol.116, B02308, doi:10.1029/2010JB007918, 2011.
-  T. Fujiwara, S. Kodaira, T. No, Y. Kaiho, N. Takahashi, and Y. Kaneda, “The 2011 Tohoku-oki Earthquake: Displacement reaching the trench axis,” Science, Vol.334, doi10.1126/science.1211554, 2011.
-  K. Satake, Y. Fujii, T. Harada, and Y. Namegaya, “Time and space distribution of coseismic slip of the 2011 Tohoku Earthquake as inferred from tsunami waveform data,” Bull. Seismol. Soc. Am., Vol.103, pp. 1473-1492, doi: 10.1785/0120120122, 2013.
-  A. Sakaguchi, F. Chester, D. Curewitz, O. Fabbri, D. Goldsby, G. Kimura, C.-F. Li, Y. Masaki, E. J. Screaton, A. Tsutsumi, K. Ujiie, and A. Yamaguchi, “Seismic slip propagation to the up-dip end of plate boundary subduction interface faults: Vitrinite reflectance geothermometry on Integrated Ocean Drilling Program NanTroSEIZE cores,” Geology, Vol.39, pp. 395-398, doi: 10.1130/G31642.1, 2011.
-  Y. Yokota, T. Ishikawa, S. Watanabe, T. Tashiro, and A. Asada, “Seafloor geodetic constraints on interplate coupling of the Nankai Trough megathrust zone,” Nature, Vol.534, pp. 374-377, doi:10.1038/nature17632, 2016.
-  T. Usami, “Overview of Japanese damage earthquakes,” Latest edition, University of Tokyo Press, p. 605, 2003.
-  T. Hori, “Mechanisms of separation of rupture area and variation in time interval and size of great earthquakes along the Nankai Trough,” southwest Japan. J. Earth Simulator, Vol.5, pp. 8-19, 2006.
-  Y. Kaneda, K. Kawaguchi, E. Araki, H. Matsumoto, T. Nakamura, S. Kamiya, K. Ariyoshi, T. Hori, T. Baba, and N. Takahashi, “Development and application of an advanced ocean floor network system for megathrust earthquakes and tsunamis,” Seafloor observatories, In: Favali, P. et al. (Eds.), Springer Praxis Books, pp. 643-663, doi.org/10.1007/978-3-642-11374-1_25, 2015.
-  K. Kawaguchi, S. Kaneko, T. Nishida, and T. Komine, “Construction of the DONET real-time seafloor observatory for earthquakes and tsunami monitoring,” Seafloor Observatories, P. Favali et al., Springer Praxis Books, doi: 10.1007/978-3-642-11374-1_Vol.10, pp. 211-228, 2015.
-  N. Takahashi, M. Ishibashi, K. Sueki, R. Obayashi, T. Baba, and Y. Kaneda, “Construction of realtime tsunami prediction system using tsunami amplification,” The 25th Ocean Engineering Symposium, OES25-040, 2015.
-  T. Baba, N. Takahashi, and Y. Kaneda,“Near-field tsunami amplification factors in the Kii Peninsula,” Japan for Dense Oceanfloor Network for Earthquakes and Tsunamis (DONET). Mar. Geophys. Res., doi: 10.1007/ s11001-013-9189-1, 2013.
-  M. Kido, Y. Osada, H. Fujimoto, R. Hino, and Y. Ito, “Trench-normal variation in observed seafloor displacement associated with the 2011 off-Tohoku earthquake,” Geophys. Res. Lett., Vol.38, No.24, doi:10.1029/2011GL050057, 2011.
-  N. Takahashi, Y. Ishihara, T. Fukuda, H. Ochi, J. Tahara, T. Mori, M. Deguchi, M. Kido, Y. Ohta, R. Hino, K. Mutoh, G. Hashimoto, O. Motohashi, and Y. Kaneda, “Buoy Platform Development for Observation of Tsunami and Crustal deformation,” IAG sympo., 2015.
-  Japan Cabinet Office, “Fault models for Tsunami – Tsunami fault models and the height, inundation areas –, Investigation Committee for Nankai trough huge earthquake fault models (Secondary report),” 2012, http://www.bousai.go.jp/jishin/nankai/model/
-  T. Baba and P. R. Cummins, “Contiguous rupture areas of two Nankai earthquakes revealed by high-resolution tsunami waveform inversion,” Geophys. Res. Lett., Vol.32, doi: 10.1029/004GL022320, 2005.
-  M. Takaesu, H. Horikawa, K. Sueki, N. Takahashi, A. Sonoda, and S. Tsuboi,“ Development of a Web Application System for Seismic Waveform Data Observed in Real Time With the Seafloor Seismic Network DONET,” Vol.50, No.3, pp. 87-91, 2016.
-  Tokushima prefecture, “Arrival times for receiving effects of tsunami and maximum tsunami height,” 2012, http://anshin.pref. tokushima.jp/docs/2012121000010/files/toutatujikan.pdf