STUDIES ON REPRODUCIBILITY INDICES IN NUMERICAL SIMULATION OF PAST TSUNAMIS

Abstract

 Among the indices for evaluating the reproducibility in numerical simulations of past tsunamis, the geometric standard deviation k of the ratio of the tsunami trace height and the calculated water level was the focus, and the value of k and the changing factors were examined. For tsunamis that occurred around Japan and in the Indian Ocean, collection and analysis of reproduction calculation results of 2D shallowwater models using highly reliable trace records were performed. Results show that the criteria for determining the validity of the analysis model using Aida's indices proposed by the JSCE are appropriate. Also, the reproducibility improved as the number of points with large trace heights were included, and that the upper limit of the ratio between the tsunami trace height and the calculated water level decreased as the calculated water level increased. Furthermore, to obtain the same level of reproducibility as the wide-area analysis results in a tsunami caused by an Mw9 class giant earthquake, it is necessary to target a coastal area that is more than half the length of the tsunami source.