Numerical modeling of waves for a tsunami early warning system

Numerical modeling of waves for a tsunami early warning system
However it is well recognized that Stromboli has also the potential to produce
large catastrophic tsunami (return period of thousands of years), which can
be the consequence of the lateral collapse of the volcanic cone. Numerical
simulations of a possible catastrophic tsunamis were carried out by Tinti
et al. (2003). In their work they have reproduced the collapsing of the
lateral flank of Stromboli, which creates the Sciara del Fuoco slope, using a
numerical model based on a lagrangian approach, and the associated tsunami
generation and propagation. Assuming a landslide of about 1 km 3 , the
tsunami generated presents a maximum wave height in front of the Sciara
del Fuoco of about 60 m, with a period of 100 s.
In the following sections some model simulations of possible tsunami
scenario in the South Tyrrhenian Sea, generated at Stromboli island are
presented. No detailed reproduction of the wave generation mechanism
is given, because the focus of the present application is mostly on the
propagation processes. Use is therefore made of the results of Tinti et
al. (2003; 2006b), which on the contrary carefully modeled the landslide
kinematic and its effects on the waves. The first section describes a simulation
of a tsunami scenario, as the one reproduced by Tinti et al. (2003), where
awave60m high is supposed to occur in front of the Sciara del Fuoco, and
that involves the Aeolian islands. The other section is aimed at reproducing
a smaller tsunamis event, as that of 30 th December 2002, and testing the
model as if it would work in real time.
5.2 Numerical model application to the
Tyrrhenian Sea
In this research we have applied our model to simulate a Tyrrhenian tsunamis
scenario caused by a landslide fall from the flank of Stromboli island. The
focus of the present application is mostly on the propagation processes.
The computational domain is that enclosed into the dashed rectangle
in figure 5.4. The modeled time series is 20,000 s long, with a Δt equal
to 5 s, leading to 4,000 time steps, which correspond to the same number
of frequencies to be solved. By inspection of the Fourier Transform of
the reproduced wave field, the frequencies at which the energy content
is significantly larger than zero and that consequently are worth to be
reproduced are identified as those in the interval 0.00005