The Locus of Tsunami Runup Frequency Distributions

Abstract

In June 1978, the Environmental Center issued a review of the "Coastal High-Hazard Zone as Mapped for the National Flood Insurance Program" (Cox, 1978). I have recently been made aware of a problem with the determination of the coastal high hazard zone that I did not anticipate in that review. This problem has to do with the assumption that the near-shore tsunami runups and the frequency distributions on which the zone limits are based could be taken to apply at a location of 200 feet inland from the shoreline. In this review I detail the problem, trace its source, and suggest certain courses of action to reduce it.