Regional Variation of the Formulae for the Determination of Tsunami Magnitude in and around Japan
Year: 1995
Type: article
Abstract: Previous equation for the tsunami-magnitude scale after Abe (1981) has been re-examined using a more general form: M10=logA+a log Δ+b, where Mto is tsunami magnitude, A is the maximum double amplitude of tsunami as recorded on a tide gage, Δ is the shortest distance along oceanic path from the earthquake epicenter to a tide station, and a and b are constants. ABE (1981) used a=1 and b=5.55 in his determination of tsunami magnitude. This paper demonstrates, using more extensive sets of tide records, that the constants, a and b, vary regionally. For instance, a=0.86 and b=5.96 for tsunamis along the Pacific coasts in and around Japan, and a=0.52 and b=6.56 for tsunamis in the Japan Sea. These constants vary even in more regional scales and may depend on the submarine topography along a tsunami path. Renewed equations should be used for the determination of tsunami magnitude.
Author: Hideo WATANABE
Institution: Japan Weather Association (Japan)
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2605823926