Regional tsunami hazard maps for the Far East coast of the Russian Federation built in the framework of the PTHA methodology

Abstract

В работе идет речь о реализации методики вероятностного цунамирайонирования побережья, известной под названием PTHA (Probabilistic Tsunami Hazard Assessment), для создания обзорных карт цунамиопасности дальневосточного побережья России. Обсуждаются методологические основы такого подхода, проблемы построения сейсмотектонических моделей основных цунамигенных зон, численные методики получения расчетных каталогов высот волн на побережье. Приведены примеры обзорных карт для различных повторяемостей, построенных с применением методики PTHA и представленных с помощью созданного веб-приложения WTMap. Упоминаются также некоторые проблемы применения методики PTHA, связанные как с недостаточностью данных наблюдений, так и со сложностью выполнения большого объема сценарного численного моделирования. The article describes the results of the implementation of the PTHA (Probabilistic Tsunami Hazard Assessment) methodology for creating the overview maps of tsunami hazard for the Far East coast of the Russian Federation. Such maps show the characteristics of the catastrophic impact of tsunami waves on the coast and the probability of their exceeding in a given period of time. The methodological basis of the PTHA approach to the assessment of tsunami hazard, the problems of constructing seismotectonic models of the main tsunamigenic zones, mathematical models and algorithms for calculating probability estimates of tsunami danger are discussed. The version of the PTHA methodology outlined in the article is implemented as a “WTmap” Web-application that has an access to the entire observational information related to coastal tsunami zoning and software packages used. The application allows to obtain the estimates of the expected tsunami heights and their recurrence estimates and to map them on specific parts of the Far Eastern coast of the Russian Federation. The obtained estimates can be quickly recalculated when replacing the observational catalogs with more complete and reliable ones, with the addition of new, previously absent events or the revision of their parameters, as well as the results of new scenario calculations. Examples of overview maps for various recurrence intervals, constructed using the PTHA methodology and presented using the “WTMap” application, are given. Some problems of using the PTHA methodology related to the lack of available observational data and to the complexity of performing a large amount of scenario simulations are also discussed.