Mathematical Modeling in Application to Regional Tsunami Warning Systems Operations

Abstract

Catastrophic tsunamis that flooded the ocean coast in the past had taken many human lives and destroyed the infrastructure of the coastal areas in the Pacific and elsewhere. Recent tragic events in the Indian Ocean motivated governments to develop new and improve the existing tsunami warning systems capable to mitigate the impact of catastrophic events. In the future, regional tsunami warning systems will be integrated into a network including both the systems currently being developed and the existing warning systems (in the past, tsunami warning systems had been deployed to protect the coastal areas in Japan, USA, Russia, Australia, Chile and New Zealand).The present study, conducted by the Institute of Computational Technologies in collaboration with other research institutes in Novosibirsk, is directed to the design of a new generation of the tsunami warning system for the Pacific coast of Kamchatka. The main purpose of the present study is to develop the computational methodology allow us to build a database of potential tsunamigenic sources that impose the imminent tsunami risk for the eastern coast of Kamchatka Peninsula. In the first stage of the project, a set of basic model sources of tsunamigenic earthquakes is defined. These model sources are used to calculate the initial water elevation in the source area that are used as initial conditions for dynamic modeling of tsunami propagation in the selected geographical region near the Kamchatka east coast. The next stage is the modeling of propagation and transformation of tsunami waves on the way from the source area towards the coast. This information is presented as a decision support system intended for use by persons on duty who are responsible for initiating tsunami mitigation procedures such as evacuation of people and sending ships away from the dangerous harbors and bays.The project involves numerical solution of a large number of instances of wave hydrodynamics problems. At the same time, interpretation of the results requires non-trivial postprocessing and development of a specialized information systems. Numerical calculation of tsunami propagation in the ocean with a real bathymetry for multiple combinations of the model earthquake sources with high spatial resolution constitutes the major part of the computational requirements of the project. The amount of computation resources needed for numerical modeling of tsunami propagation implies the use of high performance computers and may require adaptation of numerical algorithms to specific computing platforms.In the future, this approach may be extended to other tsunamigenic areas in the Pacific and the Indian oceans. In the latter case, we plan to consider the problem of defining the extension of the coastal zone that is the subject for flooding by tsunami waves. This would require to perform run-up calculation. To achieve the necessary accuracy in reproducing of tsunami behavior in the coastal areas, we will need to take into account such features of the coastal area as small rivers, lakes and swamps. This will significantly increase the amount of computational resources needed both during the development of numerical models and algorithms and in the production runs.KeywordsWave HeightModel SourceTsunami WaveTide GageTsunami PropagationThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.