The Assessment of Tsunami Hazard for the Coast of the Korf Bay, Bering Sea: Numerical Simulation

Abstract

This paper discusses the results of solving the problem of tsunami hazard assessment for the northeastern coast of Kamchatka around the village of Korf which is situated on a sand spit in the northwestern part of the eponymous bay. This assessment was based on the “worst case” procedure. The seismicity and historical data on tsunami occurrences in the western Bering Sea were examined to identify three tsunami-generating zones: the near zone (the Bering Sea part), the regional zone (the Aleutian part), and the far (Chilean) zone as posing the greatest tsunami hazard for this stretch of the northeastern coast of Kamchatka. An analysis of seismicity and tectonics of the source zones yielded sets of modeled tsunami-generating earthquakes that are typical of each. For these sets we performed numerical modeling of tsunami generation and propagation which has identified the most dangerous model sources. The sea level rises due to these sources for the Korf area were 1.3 m for earthquakes from the near (Bering Sea) zone, 2.4 m for the regional (Aleutian) zone, and 2.5 m for the far (Chilean) zone. The next step consisted in more accurate calculations for such earthquakes in sequences of nested calculation grids, yielding characteristics of tsunami effects on the shore. The main results of this study consist in identification of tsunami-generating zones that are the most dangerous for the Korf Spit, selection of the model earthquakes for these, and estimation of extreme tsunami wave heights posing hazard for this coast segment.