To promote effective disaster countermeasures against possible tsunamis in the future, an effective application of tsunami hazard information is important. However, there were insufficient systems available for utilizing and applying various tsunami hazard information. Based on this situation, we developed and have been improving the Japan Tsunami Hazard Information Station (J-THIS), an open Web system available as a public portal for providing tsunami hazard information based on the probabilistic tsunami hazard assessment (PTHA). It provides tsunami hazard information through the following services: map services, data download services, and Web application programming interface (API) services. Based on the PTHA along the Nankai Trough, the J-THIS provides distributions of exceedance probability of tsunami heights for 30 years, tsunami hazard curves, earthquake fault models, tsunami heights for each earthquake fault model, and bathymetric charts. To illustrate the use of the J-THIS, understanding how existing coastal structures will protect us against tsunamis while enabling the local governments to set investment priorities in disaster risk reduction and resilience is key.

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