A new research group has been formed to enhance disaster countermeasures for imminent M9-class earthquakes along the Kuril Trench. One key area of focus is tsunami evacuation, crucial due to the significant human impact expected from the Kuril earthquake. The group has reported new findings and developments that identify weaknesses in anti-disaster plans, address gaps in measures, and propose new countermeasure tactics. Fundamental observations, field work, data analysis and accumulation, which are essential for future crustal monitoring, earthquake occurrence probability assessment, and hazard assessment, have also been conducted. The work breakdown structure (WBS) concept forms the foundation of the group’s strategy and the roles of each team. The WBS helps in recognizing expected outcomes, understanding the relationships among research agendas, and identifies missing elements in current research plans. Group research is well-suited for disaster-related issues in that it provides multifaceted, multilayered, and multitrack perspectives, allowing for mutual verification to avoid unexpected pitfalls in disaster countermeasures. Hazard and risk evaluation research and related social collaborative activities are key to enhancing disaster preparedness in this region.

1. [1] Z. Altamimi et al., “ITRF2020 plate motion model,” Geophys. Res. Lett., Vol.50, No.24, Article No.e2023GL106373, 2023. https://doi.org/10.1029/2023GL106373
2. [2] The Headquarters for Earthquake Research Promotion, Earthquake probability, “Long term evaluation of seismic activity along the Kuril trench (3rd edition),” 2017 (in Japanese). https://www.jishin.go.jp/main/chousa/kaikou_pdf/chishima3.pdf [Accessed March 27, 2025]
3. [3] F. Nanayama, et al., “Unusually large earthquakes inferred from tsunami deposits along the Kuril trench,” Nature, Vol.424, pp. 660-663, 2003. https://doi.org/10.1038/nature01864
4. [4] Y. Sawai et al., “Aperiodic recurrence of geologically recorded tsunamis during the past 5500 years in eastern Hokkaido, Japan,” J. Geophys. Res., Vol.114, Article No.B01319, 2009. https://doi.org/10.1029/2007JB005503
5. [5] C. Hashimoto et al., “Interplate seismogenic zones along the Kuril–Japan trench inferred from GPS data inversion,” Nat. Geosci., Vol.2, pp. 141-144, 2009. https://doi.org/10.1038/ngeo421
6. [6] J. P. Loveless and B. J. Meade, “Geodetic imaging of plate motions, slip rates, and partitioning of deformation in Japan,” J. Geophys. Res., Vol.115, Article No.B02410, 2010. https://doi.org/10.1029/2008JB006248
7. [7] E. O. Lindsey et al., “Slip rate deficit and earthquake potential on shallow megathrusts,” Nat. Geosci., Vol.14, pp. 321-326, 2021. https://doi.org/10.1038/s41561-021-00736-x
8. [8] K. Ioki and Y. Tanioka, “Re-estimated fault model of the 17th century great earthquake off Hokkaido using tsunami deposit data,” Earth Planetary Sci. Lett., Vol.433, pp. 133-138, 2016. https://doi.org/10.1016/j.epsl.2015.10.009
9. [9] Y. Asano, K. Obara, and Y. Ito, “Spatiotemporal distribution of very-low frequency earthquakes in Tokachi-oki near the junction of the Kuril and Japan trenches revealed by using array signal processing,” Earth Planet Space, Vol.60, pp. 871-875, 2008. https://doi.org/10.1186/BF03352839
10. [10] T. Nishikawa et al., “The slow earthquake spectrum in the Japan Trench illuminated by the S-net seafloor observatories,” Science, Vol.365, pp. 808-813, 2019. https://doi.org/10.1126/science.aax5618
11. [11] S. Baba et al., “Comprehensive detection of very low frequency earthquakes off the Hokkaido and Tohoku Pacific coasts, Northeastern Japan,” J. Geophys. Res., Vol.125, Article No.e2019JB017988, 2020. https://doi.org/10.1029/2019JB017988
12. [12] The National Disaster Management Council, “Report on measures for large earthquakes along the Japan and Kuril trenches,” 2022 (in Japanese). https://www.bousai.go.jp/jishin/nihonkaiko_chishima/WG/pdf/220322/shiryo03.pdf [Accessed March 27, 2025]
13. [13] Council for Science and Technology, “The Second Earthquake and Volcano Hazards Observation and Research Program,” 2019 (in Japanese). https://www.mext.go.jp/b_menu/shingi/gijyutu/gijyutu6/toushin/1413118.htm [Accessed March 27, 2025]
14. [14] National Research Institute for Earth Science and Disaster Resilience, “NIED S-net,” 2019. https://doi.org/10.17598/nied.0007
15. [15] M. Ebara et al., “ Research on pre-modern earthquakes based on fusion of humanities and sciences,” J. Disaster Res., Vol.15, No.2, pp. 76-86, 2020. https://doi.org/10.20965/jdr.2020.p0076
16. [16] Review Committee on Information Dissemination to Raise Awareness of Potential Earthquakes along the Japan Trench and the Kuril Trench, “Report of the review committee on information dissemination to raise awareness of potential earthquakes along the Japan Trench and the Kuril Trench,” 2022 (in Japanese). https://www.bousai.go.jp/jishin/nihonkaiko_chishima/kohatsu/pdf/houkoku_honbun.pdf [Accessed March 27, 2025]
17. [17] Y. Okuno and Y. Hashimoto, “Situation and issues in measures against tsunami disasters in the Chishima trench coastal municipality—A case study of Kushiro, Hokkaido, Japan—,” Int. Association of Geo-informatics (IAG’i) 2023, Article No.D6-02, 2023 (in Japanese).
18. [18] Y. Hashimoto, “Black-out and white-out,” Chiri (Geography), Vol.801, pp. 16-26, 2022 (in Japanese).
19. [19] N. Mitsui and Y. Hashimoto, “Spatial analysis of evacuation from tsunami in Tomakomai city, Hokkaido,” Proc. of the 31st Annual Meeting of the Geographic Information Systems Conf., Article No.B-1-6, 2022 (in Japanese).
20. [20] H. Fukada and Y. Hashimoto, “A multi-agent simulation of evacuation behavior toward tsunami shelter buildings: A geographical study conducted in Central Kushiro, Hokkaido,” Geogr. Stud., Vol.96, pp. 7-18, 2021 (in Japanese). https://doi.org/10.7886/hgs.96.7
21. [21] D. Shiozaki and Y. Hashimoto, “System development for Tsunami evacuation drill using ICT and Tsunami inundation simulation data,” J. Disaster Res., Vol.19, No.1, pp. 72-80, 2024. https://doi.org/10.20965/jdr.2024.p0072
22. [22] T. Imai et al., “Study on evaluation of the effectiveness of measures to diversify Tsunami evacuation means in urban areas,” Research Report, No.445, Northern Building Research Institute Building Research Department Local Independent Administrative Agency Hokkaido Research Organization, 2024 (in Japanese). https://www.hro.or.jp/upload/51461/R5_houkokusyo445.pdf [Accessed March 27, 2025]
23. [23] Y. Nishimura et al., “Properties of tsunami deposits observed by a high-density excavation survey by geoslicers,” Japan Geoscience Union Meeting 2023, Article No.MIS16-P03, 2023 (in Japanese).
24. [24] Y. Takashimizu, Y. Nishimura, and K. Iwaki, “Spatial distribution of the 17th century tsunami deposits in the western Mukawa city, Hokkaido, northern Japan,” Japan Geoscience Union Meeting 2024, Article No.MIS20-P01, 2024 (in Japanese).
25. [25] Y. Nishimura and T. Chiba, “Coseismic and postseismic deformation associated with the 17th-century megathrust earthquake along the Kuril Trench estimated by diatom analysis,” Japan Geoscience Union Meeting 2023, Article No.SSS13-06, 2023 (in Japanese).
26. [26] Y. Tanioka, “Tsunami simulation method assimilating ocean bottom pressure data near a tsunami source region,” Pure Appl. Geophys., Vol.175, pp. 721-729, 2018. https://doi.org/10.1007/s00024-017-1697-5
27. [27] Y. Tanioka, “Improvement of near-field tsunami forecasting method using ocean-bottom pressure sensor network (S-net),” Earth Planets Space, Vol.72, Article No.132, 2020, https://doi.org/10.1186/s40623-020-01268-1
28. [28] T. Saito and H. Tsushima, “Synthesizing ocean bottom pressure records including seismic wave and tsunami contributions: Toward realistic tests of monitoring systems,” J. Geophys Res., Vol.121, No.11, pp. 8175-8195, 2016. https://doi.org/10.1002/2016JB013195
29. [29] T. Oishi, Y. Tanioka, and Y. Yamanaka, “Tsunami forecasting method using time-averaged ocean bottom pressure data,” Japan Geoscience Union Meeting 2023, Article No.HDS06-14, 2023 (in Japanese).
30. [30] Y. Atobe and Y. Tanioka, “Tsunami forecast method using Tsunami data assimilation with real-time source estimation,” Japan Geoscience Union Meeting 2024, Article No.HDS11-P07, 2024 (in Japanese).
31. [31] Y. Yamanaka and Y. Tanioka, “Short-wave run-ups of the 1611 Keicho tsunami along the Sanriku Coast,” Prog. Earth Planet Sci., Vol.9, Article No.37, 2022. https://doi.org/10.1186/s40645-022-00496-1
32. [32] Y. Yamanaka and Y. Tanioka, “Tsunami waveform inversion using Green’s functions with advection effects: Application to the 2003 Tokachi-Oki earthquake,” Earth Planets Space, Vol.76, Article No.71, 2024. https://doi.org/10.1186/s40623-024-02006-7
33. [33] N. Takai and M. Shigefuji, “Source characteristics of moderate to large earthquakes occurring in the southern part of the Kuril Trench,” Summaries of Technical Papers of Annual Meeting Architectural Institute of Japan B-2, Vol.2023, pp.743-744, 2023 (in Japanese).
34. [34] N. Takai, M. Shigefuji, M. Iwasaki, “Source characteristics of the earthquakes around the south part of the Kuril trench,” IUGG General Assembly, Article No.IUGG23-0482, 2023. https://doi.org/10.57757/IUGG23-0482
35. [35] W. Hirose and H. Takahashi, “Liquefaction history of the ground in the area around the Kuril Islands Trench, Hokkaido, Japan, based on archaeological data,” Abstract of Seismological Society of Japan Meeting 2022, Article No.S22-04, 2022 (in Japanese).
36. [36] F. Tomita et al., “Shallow interplate slip deficit inferred from GNSS-Acoustic observations off Nemuro,” Japan Geoscience Union Meeting 2024, Article No.SGD02-02, 2024 (in Japanese).
37. [37] T. Iinuma et al., “GNSS-acoustic observation using the wave glider to detect the seafloor crustal deformation (5),” Japan Geoscience Union Meeting 2024, Article No.SCG48-P01, 2024, (in Japanese)
38. [38] K. Katsumata and M. Nakatani, “Testing the seismic quiescence hypothesis through retrospective trials of alarm-based earthquake prediction in the Kurile–Japan subduction zone,” Earth Planets Space, Vol.73, Article No.100, 2021. https://doi.org/10.1186/s40623-021-01418-z
39. [39] R. Azuma et al., “Crustal structure in the 17th century Kuril earthquake and its linkage to the occurrence of the large shallow slip,” Abstract of Annual Meeting of Seismological Society of Japan 2023, Article No.S06-05, 2023 (in Japanese).
40. [40] N. Anggraini and H. Takahashi, “Searching for Very Low Frequency Earthquake (VLFE) around Western Kuril Trench,” Abstract of Annual Meeting of Seismological Society of Japan 2022, Article No.S09-24, 2023.
41. [41] R. Azuma et al., “Shallow VLFE observation at the Erimo-oki, southern off Hokkaido, using a broadband OBS array and F-net,” Abstract of Annual Meeting of Seismological Society of Japan 2022, Article No.S22-16, 2022 (in Japanese).
42. [42] Y. Hayashi, H. Takahashi, and T. Motoyoshi, “Public awareness survey on the recognition and response of the Off the Coast of Hokkaido and Sanriku Subsequent Earthquake Advisory in Hokkaido, Japan,” J. Societal Safety Sci., Vol.14, Article No.107, 2024 (in Japanese).
43. [43] Y. Hayashi, “Public recognition and problems of uncertain earthquake information in Japan,” Japan Geoscience Union Meeting 2024, Article No.HDS10-01, 2024 (in Japanese).
44. [44] Japan Meteorological Agency web site, “Search for past meteorological data,” 2024. https://www.data.jma.go.jp/obd/stats/etrn/index.php?prec_no=19&block_no=47418&year=&month=&day=&view=h0 [Accessed March 27, 2025]
45. [45] F. Kato et al., “Analysis on effects of tsunami evacuation workshops based on decision-making factors for evacuation,” J. of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering), Vol.65, Issue 1, pp. 1356-1360, 2009 (in Japanese). https://doi.org/10.2208/kaigan.65.1356
46. [46] Y. Nara, “Inquiries Into Risk Communication,” Foundation for the Promotion of The Open University of Japan, 2023 (in Japanese).
47. [47] M. Uchida and S. Hara, “Deficit model, one-way communication, and two-way communication: Reassembling key concepts in science communication,” J. of Science and Technology Studies, Vol.18, pp. 208-220, 2020 (in Japanese). https://doi.org/10.24646/jnlsts.18.0_208
48. [48] Y. Sunahara and Y. Tezuka, “Foundation of Public Analysis (New Edition),” Foundation for the Promotion of The Open University of Japan, 2022 (in Japanese).