Changes in Scale Distribution of Sea Disasters since 1945

Abstract

Larger disasters are less frequent. The dependence of the disaster frequency on the scale of the disaster is represented by the location of the characteristic curve on a log-log diagram. The characteristic curve of sea disasters for each three-year period since 1964 was constructed and compared with each other and with the characteristic curve for the period from 1945 till 1963. Significant differences are found between the two characteristic curves for the first 19 years period to 1963 and the following 20 years period since 1964. This fact indicates that Japanese ships recovered gradually from the war-time abnormal situations in 1945 and, since 1964, they are in an improved stable condition. The stable characteristic curve of sea disasters since 1964 is compared with such disasters as of the coal mine, the passenger air transport, the fire, the typhoon, and some others.