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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS003 Oral Presentation 1862
A Possible Method of Tsunami Early Warning
Dr. Yury Korolev
At present Tsunami Warning Services (TWS) in US, Japan and Russiaworks well enough not missing
significant tsunamis. At the same time TWS commit a great many false tsunami alarms (up to 75-78%
of total alarms since it came into existence). It is obvious, that false tsunami alarms are accompanied by
various losses. As a result of some recent false tsunami alarms on Hawaii the average cost of lost
business and productivity was estimated to be $ tens millions in every event. It is possible to reduce a
number of false alarms using additional information on a formed tsunami obtained in the open ocean.
Use of this information can provide more accurate prediction. The method of the short-term tsunami
forecast using information of remote level gauge is presented in this paper. This method is based on
well-known reciprocity principle. This method permits to calculate the form of tsunami wave near every
specific coast point. The sea level information in remote point and the only seismological information
about time of beginning and co-ordinates of the earthquake are needed for tsunami wave form
prediction. The suggested method for tsunami estimation from the data of a sea level gauge was tested
by means of the numerical model with actual bathymetry. To calculate tsunamis (expected ones)
tsunami sources were applied which were chosen as macroseismic ones corresponding to recent
tsunamis. Use of proposed method shows that the main wave parameters of predicted tsunami agree
sufficiently well with parameters of expected tsunami. The presenting method may be applied for shortterm
tsunami forecast regardless of tsunami generation genesis. Tsunami may be seismic one, subsea
landslide one or others. The presenting method can be used on-line not only by regional tsunami
warning service but also by local tsunami warning services. So, tsunami warning may be declared for
sites where tsunami to be of real threat. Putting this method or analogue ones into use will permit to
reduce a number of false tsunami alarms. It seems that requirements (recommendations) to TWS in
future may be as follows. TWS must announce tsunami alarm to those point only where tsunami to be
of real threat. This alarm must be accompaniedby information about predicted tsunami: number of
waves, their heights, expected time of alarm canceling. This work is supported by Russian Foundation
for Basic Research, grant 06-05-96139, Far Eastern Branch of Russian Academy of Sciences, grant 06-
III-A-07-248.
Keywords: tsunami, early warning