Tsunami Distribution Functions along the Coast: Extended

The distribution of tsunami runup heights along the coast is studied both theoretically and experimentally using observation data of historical tsunami from 1992 to 2018. The physical mechanisms leading to the lognormal distribution of tsunami runup heights along the coast are discussed, and its statistical moments are calculated. It is shown that the lognormal distribution describes well the measurements of tsunami characteristics over the past 30 years. Special attention is paid to the multi-source 2018 Palu– ulawesi tsunami, which was generated by an earthquake with magnitude 7.5 and numerous subsequent landslides. It is shown that even in this special case the lognormal distribution is a rather good approximation.