Journal cover Journal topic
Natural Hazards and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Nat. Hazards Earth Syst. Sci., 16, 2593-2602, 2016
https://doi.org/10.5194/nhess-16-2593-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
06 Dec 2016
Fast evaluation of tsunami scenarios: uncertainty assessment for a Mediterranean Sea database
Irene Molinari1,2, Roberto Tonini1, Stefano Lorito1, Alessio Piatanesi1, Fabrizio Romano1, Daniele Melini1, Andreas Hoechner3, José M. Gonzàlez Vida4, Jorge Maciás5, Manuel J. Castro5, and Marc de la Asunción5 1Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Roma 1, Via di Vigna Murata 605, 00143, Roma, Italy
2Department of Earth Sciences, Institute of Geophysics, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, Switzerland
3GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
4Dpto. Mátematica Aplicada, Universidad de Málaga, EDANYA Group, 29071, Málaga, Spain
5Dpto. Análisis Matemático, Facultad de Ciencias, Universidad de Màlaga, EDANYA Group, 29071, Màlaga, Spain
Abstract. We present a database of pre-calculated tsunami waveforms for the entire Mediterranean Sea, obtained by numerical propagation of uniformly spaced Gaussian-shaped elementary sources for the sea level elevation. Based on any initial sea surface displacement, the database allows the fast calculation of full waveforms at the 50 m isobath offshore of coastal sites of interest by linear superposition. A computationally inexpensive procedure is set to estimate the coefficients for the linear superposition based on the potential energy of the initial elevation field. The elementary sources size and spacing is fine enough to satisfactorily reproduce the effects of M> = 6.0 earthquakes. Tsunami propagation is modelled by using the Tsunami-HySEA code, a GPU finite volume solver for the non-linear shallow water equations. Like other existing methods based on the initial sea level elevation, the database is independent on the faulting geometry and mechanism, which makes it applicable in any tectonic environment. We model a large set of synthetic tsunami test scenarios, selected to explore the uncertainty introduced when approximating tsunami waveforms and their maxima by fast and simplified linear combination. This is the first time to our knowledge that the uncertainty associated to such a procedure is systematically analysed and that relatively small earthquakes are considered, which may be relevant in the near-field of the source in a complex tectonic setting. We find that non-linearity of tsunami evolution affects the reconstruction of the waveforms and of their maxima by introducing an almost unbiased (centred at zero) error distribution of relatively modest extent. The uncertainty introduced by our approximation can be in principle propagated to forecast results. The resulting product then is suitable for different applications such as probabilistic tsunami hazard analysis, tsunami source inversions and tsunami warning systems.

Citation: Molinari, I., Tonini, R., Lorito, S., Piatanesi, A., Romano, F., Melini, D., Hoechner, A., Gonzàlez Vida, J. M., Maciás, J., Castro, M. J., and de la Asunción, M.: Fast evaluation of tsunami scenarios: uncertainty assessment for a Mediterranean Sea database, Nat. Hazards Earth Syst. Sci., 16, 2593-2602, https://doi.org/10.5194/nhess-16-2593-2016, 2016.
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We present a database of pre-calculated tsunami waveforms for the entire Mediterranean Sea, obtained by numerical propagation of uniformly spaced Gaussian-shaped elementary sources for the sea level elevation. Based on any initial sea surface displacement, the database allows the fast calculation of full waveforms of coastal sites. The resulting product is suitable for different applications such as probabilistic tsunami hazard, tsunami source inversions and tsunami warning systems.
We present a database of pre-calculated tsunami waveforms for the entire Mediterranean Sea,...
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