Tsunami Recurrence and Hazard Evaluation for the South Kuril Islands

Probabilistic Tsunami Hazard Assessment (PTHA) is used to estimate tsunami recurrence and hazard for the South Kuril Islands. The method is a further development and improvement of the Regional Statistical Tsunami Model (RSTM) developed earlier [Kaistrenko (Pure Appl Geophys 168:2065-2069, 2011) and (Pure Appl Geophys 171:3527-3538, 2014)], which differs from the commonly used variations of PTHA and is entirely based on historical tsunami observations. The method operates with tsunami height datasets exceeding a threshold height of 0.5 m and ranked in height, for each coastal location of the region. This condition is crucial; incorrect or imprecise results can arise from incomplete datasets. Based on observations from 63 coastal locations in the South Kuril region, it is shown that all ranked tsunami height data provided by existing tsunami catalogues for a period of 67 years, can be described by a single regional recurrence function. This function contains two types of scale parameters: (1) the asymptotic frequency, f, of major tsunamis in the study region, and (2) the set of characteristic tsunami heights, H*, for all locations considered. The dependences of the parameters f and H* on the observation period and amount of data were examined. As an example of the method, we construct a preliminary tsunami hazard map for the South Kuril Islands and analyze the possible errors of the estimated tsunami parameters and resulting tsunami recurrence.