Publication Date:
2018-03-16
Description:
This article has been accepted for publication in Geophysical Journal Internationa ©: 2016 Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Description:
We propose a procedure for uncertainty quantification in Probabilistic Tsunami Hazard Analysis
(PTHA), with a special emphasis on the uncertainty related to statistical modelling of the
earthquake source in Seismic PTHA (SPTHA), and on the separate treatment of subduction
and crustal earthquakes (treated as background seismicity). An event tree approach and ensemble
modelling are used in spite of more classical approaches, such as the hazard integral
and the logic tree. This procedure consists of four steps: (1) exploration of aleatory uncertainty
through an event tree, with alternative implementations for exploring epistemic uncertainty;
(2) numerical computation of tsunami generation and propagation up to a given offshore isobath;
(3) (optional) site-specific quantification of inundation; (4) simultaneous quantification
of aleatory and epistemic uncertainty through ensemble modelling. The proposed procedure
is general and independent of the kind of tsunami source considered; however, we implement
step 1, the event tree, specifically for SPTHA, focusing on seismic source uncertainty. To
exemplify the procedure, we develop a case study considering seismic sources in the Ionian
Sea (central-eastern Mediterranean Sea), using the coasts of Southern Italy as a target zone.
The results show that an efficient and complete quantification of all the uncertainties is feasible
even when treating a large number of potential sources and a large set of alternative model
formulations. We also find that (i) treating separately subduction and background (crustal)
earthquakes allows for optimal use of available information and for avoiding significant biases;
(ii) both subduction interface and crustal faults contribute to the SPTHA, with different
proportions that depend on source-target position and tsunami intensity; (iii) the proposed
framework allows sensitivity and deaggregation analyses, demonstrating the applicability of
the method for operational assessments.
Description:
Italian Flagship Project RITMARE, EC FP7 ASTARTE
(Grant agreement 603839) and STREST(Grant agreement 603389)
projects, Italian FIRB-‘Futuro in Ricerca’ project ‘ByMuR’ (Ref.
RBFR0880SR), INGV-DPC Agreement, Annex B2
Description:
Published
Description:
1780–1803
Description:
5T. Modelli di pericolosità sismica e da maremoto
Description:
JCR Journal
Keywords:
Probabilistic forecasting
;
Tsunamis
;
Earthquake interaction
;
Europe
;
04.07. Tectonophysics
;
05.06. Methods
;
05.08. Risk
;
05.01. Computational geophysics
;
04.06. Seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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