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Distribution of tsunami interevent times
Author(s) -
Geist Eric L.,
Parsons Tom
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032690
Subject(s) - exponential distribution , aftershock , scaling , poisson distribution , geology , distribution (mathematics) , seismology , hazard , probability distribution , fault (geology) , cluster analysis , constant (computer programming) , exponential function , statistical physics , statistics , geodesy , physics , mathematics , geometry , computer science , mathematical analysis , chemistry , organic chemistry , programming language
The distribution of tsunami interevent times is analyzed using global and site‐specific (Hilo, Hawaii) tsunami catalogs. An empirical probability density distribution is determined by binning the observed interevent times during a period in which the observation rate is approximately constant. The empirical distributions for both catalogs exhibit non‐Poissonian behavior in which there is an abundance of short interevent times compared to an exponential distribution. Two types of statistical distributions are used to model this clustering behavior: (1) long‐term clustering described by a universal scaling law, and (2) Omori law decay of aftershocks and triggered sources. The empirical and theoretical distributions all imply an increased hazard rate after a tsunami, followed by a gradual decrease with time approaching a constant hazard rate. Examination of tsunami sources suggests that many of the short interevent times are caused by triggered earthquakes, though the triggered events are not necessarily on the same fault.