Download Souces and scenarios for tsunami hazard assessment in the

Sources and scenarios for tsunami
hazard assessment in the
Mediterranean
A very preliminary view
Tsunami Hazard Assessment
• 1. Deterministic (usually“credible” worst tsunami,
Tinti and Armigliato, 2003)
• 2. Scenario-based assessment
• 3. Probabilistic (P for the exceedance of height H in T
years, e.g. Sørensen et al., 2012) /statistics (sizefrequency relations)
All (!) approaches suffer due to
• 1. Poor knowledge of mechanisms
• 2. Are realistic (?)
• 3. Very small ts. catalogs (simulations/synthetic
catalogs is an alternative)
Geotectonic setting
(Mascle & Mascle, 2012)
Tsunamigenic zones
(Papadopoulos et al., Mar. Geol., 2014)
Rupture zones of tsunamigenic earthquakes
(Papadopoulos & Papageorgiou, Cambridge Univ. Press, 2014)
Rupture zones of tsunamigenic earthquakes
(Papadopoulos & Papageorgiou, Cambridge Univ. Press, 2014)
Seismic criterion for the source: slowness factor
(Newman and Okal , 1998)
Seismic moment
Earthquake
Nicaragua 1992
Java 1994
Peru 1996
Flores Sea 1992
PNG 1998
Messina 1908
Amorgos 1956
7.66
7.87
7.18
8.07
6.80
7.10
7.50
Mo x 1027 (dyn.cm)
Slowness
factor, θ
3.40
5.30
2.20
5.10
0.37
0.56
3.90
-6.51
-5.76
-6.22
-4.58
-5.50
-5.39
-4.68
 E
log10 
0
M
Western Mediterranean:
Álvarez-Gómez et al. (2011a) selected various worst case
seismogenic faults
Western Mediterranean:
Álvarez-Gómez et al. (2011a) selected various worst case
seismogenic faults and calculated maximum wave elevation maps and tsunami
travel times
Western Mediterranean:
Iglesias et al. (2012) presented a reasonable present-day, sea-level
highstand numerical simulation and scenario for a tsunami excited by a
hypothetical landslide with the characteristics of the pre-historic BIG’95
debris flow occurring on the Ebro margin about 11500 cal yr BP
Strategies for developing database of
pre-simulated tsunami scenarios
1.
Discretization of a given “tsunamigenic domain” with sources
distributed on a regular grid of cells, independently on the
tsunami history. Tsunami scenarios are computed for each grid cell
and for different EQ magnitudes starting from “standard” tsunami
initial conditions (practice by Global Disasters Alerts &
Coordination System, JRC, Ulutas et al., 2012).
1.
The second approach applies when sound hypotheses on tectonic
lineaments and/or specific active and potentially tsunamigenic
faults can be made: “source-based” approach: the fault areas are
tessellated with elementary faults of suitable extension and with
focal mechanism coinciding with that of the parent source area.
(e.g adopted by the NOAA Tsunami Research Center “Short-Term
Inundation Forecast” (SIFT) operational tool).
NEARTOWARN Project: “source-based” approach
applied by UNIBO
Cyprus
Rhodes