Publication Date:
2020-10-22
Description:
The huge loss of lives and the destruction caused by the 2004 Indian Ocean tsunami
dramatically showed the need for a reassessment of tsunami hazard and risk in coastal
regions prone to this threat. It is known that many countries facing the Mediterranean
basin have been affected by several tsunamis in the past, some of which were catastrophic
over large areas.
Our work aims to quantitatively address the problem of the tsunami hazard and risk
assessment by means of numerical simulation of earthquake-induced tsunami scenarios.
The work is part of a larger project, funded by the Italian Department for Civil
Defense, whose main goal is the evaluation of the seismogenic potential and of the
probability of occurrence of strong earthquakes in Italy. Here we show some preliminary
results concerning the analysis of several simulated tsunami scenarios. On the
basis of tsunami catalogues and seismogenic source databases, we selected a set of
tectonic sources that, owing to their location and/or size, are believed to be especially
hazardous for the Italian coasts. Once the geometrical parameters of the fault are defined
(on the basis of geological and seismological evidence and constraints), we compute
the coseismic vertical displacement of the seafloor, which represents the initial
condition of the tsunami propagation problem. Then we solve the propagation equations
(the wide used shallow-water equations) through a finite difference technique.
The main outputs of a single run are the wavefields at desired times, useful to estimate
the arrival times of the wavefronts, and the maximum water elevation field that gives
at-glance information on the tsunami energy focusing during the whole propagation.
Furthermore, for those stretches of coast that are particularly vulnerable (owing to
high population density, presence of important infrastructures, etc.) we make a more
detailed analysis of the wave impact.
Among the tectonic sources we studied, the 365 AD Crete earthquake indeed represents
a serious threat for the Italian coastlines facing the Ionian Sea, where we estimated
a wave height exceeding 1-2 meters along hundreds of km of the coast. Furthermore,
the first wavefront from this source is expected to reach the coasts of southern
Italy in less than 1 hour from the origin time of the parent earthquake. This finding
stresses the need for an especially early warning by the geophysical monitoring systems
and by the Civil Defense structures.
Description:
Convenzione INGV - DPC 2004-2006
Progetti Sismologici e Vulcanologici di interesse per il Dipartimento della Protezione Civile
Progetto S2 - Valutazione del potenziale sismogenetico e probabilità dei forti terremoti in Italia
Description:
Published
Description:
Vienna, Austria
Description:
open
Keywords:
Tsunami hazard
;
Risk assessment
;
Seismogenic source
;
Mediterranean Sea
;
Southern Italy
;
04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology
;
04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
;
05. General::05.08. Risk::05.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
Poster session
Format:
3346130 bytes
Format:
application/pdf
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