Geoscience Reference
In-Depth Information
Fig. 1.5 Recurrence of tsunamis (number of events per decade) in the Pacific region between 1800
and 2005. The dark colour shows all the known tsunamis, the grey colour indicates tsunamis of
intensity
I
1 according to the Soloviev-Imamura scale
Fig. 1.6 Tsunamis of the Pacific region in the 'intensity-time' plane (see also Plate 2 in the Colour
Plate Section on page 310)
show all known tsunamis. It can be seen that the recurrence of significant tsunamis
remains approximately at the same level (about two events per year). The total
number of tsunamis, here, shows a tendency of increasing, which is related to
the progress in registering weak waves. Similar comments can also be addressed
to Fig. 1.6, in which the tsunami intensity is plotted as a function of time. It must
be stressed, here, that it would be wrong to conclude, on the basis of the presented
data, that the tsunami recurrence frequency has increased during past centuries. The
recurrence frequency of tsunamis can vary noticeably only over geological times.
The database can be applied for resolving a broad class of problems. Thus, for
example, analysis of measurements of run-up heights of tsunami waves making
use of approaches pertaining to dimensionality theory [Zav'yalov et al. (2005)] has
permitted to reveal hidden information on the symmetry of a tsunami source and on
