Probabilistic Forecasting of Tsunami Occurrences Across Various Tsunamigenic Zones of the Earth

Abstract

Stochastic tools have been developed to estimate the potential for tsunami generation in a particular region under consideration. This paper identifies 13 probable zones on the earth where there is a high likelihood for tsunami generation in the future. The conditional probabilities for future tsunami and earthquake occurrences are estimated for all the identified zones. Also, total probabilities for future tsunami events are computed. Forecasting is done on the basis of conditional probability obtained using the best fit model among Lognormal, Gamma, Log-Logistic and Weibull distributions. The obtained probabilities of tsunami are validated by calculating the region-specific threshold probabilities. Also, a country wise expectation of anticipated tsunami is developed for each zone. Zones 5 (Northwest U.S.A and Bering Sea Islands), 6 (Kuril & Kamchatka Islands) and 7 (Japan, Northeast China and Korea) have the highest ratio of tsunamigenic earthquakes to the total number of earthquakes. The zone 7 has the highest probability of tsunami occurrence in the near future as calculated from the total probability theorem. However, zones 1 (Southwest coast of South American continent), 7 and 11 (Papua New Guinea and Solomon Islands) are expected to experience a tsunami in the near future (before 2022) as per the current forecasting study.