Assessment of Tsunami Hazard for the Coast of Oktyabrsky Spit, Western Kamchatka Based on Results of Numerical Modeling

Abstract

This study is assessing the tsunami hazard for a segment of the Kamchatka western coast around the Oktyabrsky Spit. The motivation is to ensure transportation access to the village of Oktyabrsky and to the fish processing facilities situated on the Spit. The hazard estimates were derived by the worst case method. An analysis of seismicity and historical data on tsunami occurrences in the Sea of Okhotsk resulted in identification of two tsunami-generating zones that constitute threat to the Oktyabrsky coast segment, with a set of model tsunami-generating earthquakes being determined for each zone. For this set of models we conducted numerical modeling for tsunami generation and propagation, resulting in a selection of model sources that would pose the greatest threat to the coastal strip of interest. The next step involved refining calculations for these sources using a sequence of nested grids to find the parameters of tsunami impact on the coast. The main results of the present study consist in identification of tsunami-generating zones that pose the highest threat to the Oktyabrsky coast, the selection of tsunami-generating model sources in these zones, and estimates of parameters that characterize extreme tsunami waves posing threat to this coast strip.