Integrating geologic fault data into tsunami hazard studies

• Main Authors: R. Basili, M. M. Tiberti, V. Kastelic, F. Romano, A. Piatanesi, J. Selva, S. Lorito
• Format: Article
• Language: English
• Published: Copernicus Publications 2013-04-01
• Series: Natural Hazards and Earth System Sciences
• Online Access: http://www.nat-hazards-earth-syst-sci.net/13/1025/2013/nhess-13-1025-2013.pdf
• ISSN: 1561-8633; 1684-9981

We present the realization of a fault-source data set designed to become the starting point in regional-scale tsunami hazard studies. Our approach focuses on the parametric fault characterization in terms of geometry, kinematics, and assessment of activity rates, and includes a systematic classification in six justification levels of epistemic uncertainty related with the existence and behaviour of fault sources. We set up a case study in the central Mediterranean Sea, an area at the intersection of the European, African, and Aegean plates, characterized by a complex and debated tectonic structure and where several tsunamis occurred in the past. Using tsunami scenarios of maximum wave height due to crustal earthquakes (<i>M</i>_w=7) and subduction earthquakes (<i>M</i>_w=7 and <i>M</i>_w=8), we illustrate first-order consequences of critical choices in addressing the seismogenic and tsunamigenic potentials of fault sources. Although tsunamis generated by <i>M</i>_w=8 earthquakes predictably affect the entire basin, the impact of tsunamis generated by <i>M</i>_w=7 earthquakes on either crustal or subduction fault sources can still be strong at many locales. Such scenarios show how the relative location/orientation of faults with respect to target coastlines coupled with bathymetric features suggest avoiding the preselection of fault sources without addressing their possible impact onto hazard analysis results.