Tsunami risk management for crustal earthquakes and non-seismic sources in Italy

AbstractDestructive tsunamis are most often generated by large earthquakes occurring at subduction interfaces, but also other “atypical” sources—defined as crustal earthquakes and non-seismic sources altogether—may cause significant tsunami threats. Tsunamis may indeed be generated by different sources, such as earthquakes, submarine or coastal landslides, volcano-related phenomena, and atmospheric perturbations. The consideration of atypical sources is important worldwide, but it is especially prominent in complex tectonic settings such as the Mediterranean, the Caribbean, or the Indonesian archipelago. The recent disasters in Indonesia in 2018, caused by the Palu-Sulawesi magnitude Mw 7.5 crustal earthquake and by the collapse of the Anak-Krakatau volcano, recall the importance of such sources. Dealing with atypical sources represents a scientific, technical, and computational challenge, which depends on the capability of quantifying and managing uncertainty efficiently and of reducing it with accurate physical modelling. Here, we first introduce the general framework in which tsunami threats are treated, and then we review the current status and the expected future development of tsunami hazard quantifications and of the tsunami warning systems in Italy, with a specific focus on the treatment of atypical sources. In Italy, where the memory of historical atypical events like the 1908 Messina earthquake or the relatively recent 2002 Stromboli tsunami is still vivid, specific attention has been indeed dedicated to the progressive development of innovative strategies to deal with such atypical sources. More specifically, we review the (national) hazard analyses and their application for coastal planning, as well as the two operating tsunami warning systems: the national warning system for seismically generated tsunamis (SiAM), whose upstream component—the CAT-INGV—is also a Tsunami Service Provider of the North-eastern Atlantic, the Mediterranean and connected seas Tsunami Warning System (NEAMTWS) coordinated by the Intergovernmental Coordination Group established by the Intergovernmental Oceanographic Commission (IOC) of UNESCO, and the local warning system for tsunamis generated by volcanic slides along the Sciara del Fuoco of Stromboli volcano. Finally, we review the state of knowledge about other potential tsunami sources that may generate significant tsunamis for the Italian coasts, but that are not presently considered in existing tsunami warning systems. This may be considered the first step towards their inclusion in the national tsunami hazard and warning programs.

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Applicability of the Decision Matrix of North Eastern Atlantic, Mediterranean and connected seas Tsunami Warning System to the Italian tsunamis

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-843-2012 ◽

2012 ◽

Vol 12 (3) ◽

pp. 843-857 ◽

Cited By ~ 16

Author(s):

S. Tinti ◽

L. Graziani ◽

B. Brizuela ◽

A. Maramai ◽

S. Gallazzi

Keyword(s):

Indian Ocean ◽

Warning System ◽

Tsunami Warning ◽

The Other ◽

Tsunami Source ◽

Indian Ocean Tsunami ◽

Decision Matrix ◽

Tsunami Warning System ◽

North Eastern ◽

The Mediterranean

Abstract. After the 2004 Indian Ocean tsunami catastrophe, UNESCO through the IOC (Intergovernmental Oceanographic Commission) sponsored the establishment of Intergovernmental Coordination Groups (ICG) with the aim to devise and implement Tsunami Warning Systems (TWSs) in all the oceans exposed to tsunamis, in addition to the one already in operation in the Pacific (PTWS). In this context, since 2005, efforts have begun for the establishment of TWSs in the Indian Ocean (IOTWS), in the Caribbean area (CARIBE EWS) and in the North Eastern Atlantic, the Mediterranean and Connected Seas (NEAMTWS). In this paper, we focus on a specific tool that was first introduced in the PTWS routine operations, i.e., the Decision Matrix (DM). This is an easy-to-use table establishing a link between the main parameters of an earthquake and the possible ensuing tsunami in order to make quick decision on the type of alert bulletins that a Tsunami Warning Center launches to its recipients. In the process of implementation of a regional TWS for the NEAM area, two distinct DMs were recently proposed by the ICG/NEAMTWS, one for the Atlantic and the other for the entire Mediterranean area. This work applies the Mediterranean NEAMTWS DM to the earthquakes recorded in Italy and compares the action predicted by the DM vs. the action that should be appropriate in view of the observed tsunami characteristics with the aim to establish how good the performance of the Italian TWS will be when it uses the DM for future events. To this purpose, we make use of the parametric catalogue of the Italian earthquakes (CPTI04) compiled in 2004 and the most recent compilation of the Italian tsunami, based on the Italian Tsunami Catalogue of 2004 and the subsequent revisions. In order to better compare the TWS actions, we have identified four different kinds of action coding them from 0 to 3 according to the tsunami severity and have further considered three different distance ranges where these actions apply, that is local, regional and basin-wide, that refer to the distance of the message recipients from the tsunami source. The result of our analysis is that the actions prescribed by the DM are adequate only in 45%–55% of the cases, overestimations are about 37% and underestimations are the rest. As a whole, the predictive ability of the DM is not satisfactory, which implies that recipients have the difficult task in managing bulletins carrying a great deal of uncertainty and on the other hand also suggests that strategies to improve the DM or to go beyond the DM need to be found.

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Bodrum–Kos (Turkey–Greece) Mw 6.6 earthquake and tsunami of 20 July 2017: a test for the Mediterranean tsunami warning system

Geoscience Letters ◽

10.1186/s40562-017-0097-0 ◽

2017 ◽

Vol 4 (1) ◽

Cited By ~ 20

Author(s):

Mohammad Heidarzadeh ◽

Ocal Necmioglu ◽

Takeo Ishibe ◽

Ahmet C. Yalciner

Keyword(s):

Warning System ◽

Tsunami Warning ◽

Tsunami Warning System ◽

The Mediterranean

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Review of "Tsunami Hazard assessment and Scenarios Database for the Tsunami Warning System for the coast of Oman"

10.5194/nhess-2018-221-rc2 ◽

2018 ◽

Author(s):

Joern Behrens

Keyword(s):

Hazard Assessment ◽

Warning System ◽

Tsunami Hazard ◽

Tsunami Warning ◽

Tsunami Warning System ◽

Tsunami Hazard Assessment

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Tsunami Hazard assessment and Scenarios Database for the Tsunami Warning System for the coast of Oman

10.5194/nhess-2018-221 ◽

2018 ◽

Cited By ~ 2

Author(s):

Íñigo Aniel-Quiroga ◽

José A. Álvarez-Gómez ◽

Mauricio González ◽

Jara Martínez Sánchez ◽

Laura M. Parro ◽

...

Keyword(s):

Hazard Assessment ◽

Warning System ◽

Tsunami Hazard ◽

Assessment System ◽

Tsunami Warning ◽

Tsunami Warning System ◽

Worst Case ◽

Makran Subduction Zone ◽

Tsunami Hazard Assessment ◽

Scenario Database

Abstract. Advances in the understanding of tsunami impacts allow developing products to assess its consequences in tsunami-prone areas, as it is the case of the coast of the Sultanate of Oman. This paper presents the followed methodology and the obtained results for the assessment of the tsunami hazard of the coast of Oman and the development of the scenario database that feeds its Tsunami Warning System (TWS). Initially, a seismo-tectonic analysis of the area was carried out, focused on identifying the seismic areas whose earthquakes could generate tsunamis affecting the coast of Oman. A database of 3181 tsunamigenic sources was characterized by means of the parameters that define their focal mechanisms. This database includes scenarios with magnitudes Mw ranging from 6.5 to 9.25 within the study area, but it is especially focused on the Makran Subduction Zone (MSZ). The 3181 cases were numerically propagated to feed the database and to work as precomputed scenarios for the TWS: In case of tsunami, the results for the closest precomputed scenario (in location and magnitude) are shown. From the database, 7 worst-case scenarios were selected and computationally simulated at national and local scale, in 9 municipalities all along the coast of Oman, resulting in tsunami hazard maps containing relevant variables in the flooded area, such as the inundation water depth and the drag level (hazard degree for people instability). Finally, in order to manage conveniently the results, an online tool, called Multi-Hazard Risk Assessment System (MHRAS), was developed. This tool is a viewer that contains an easy-to-use application, including the results of the tsunami hazard assessment and the tsunami scenario database, and the selection algorithm to choose the proper case among the precomputed ones. The results of this research are part of the National Multi-Hazard Early Warning System of Oman (NMHEWS).

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Japan's tsunami warning system retreats

Nature ◽

10.1038/news.2011.477 ◽

2011 ◽

Cited By ~ 6

Author(s):

David Cyranoski

Keyword(s):

Warning System ◽

Tsunami Warning ◽

Tsunami Warning System

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Potential deployment of offshore bottom pressure gauges and adoption of data assimilation for tsunami warning system in the western Mediterranean Sea

Geoscience Letters ◽

10.1186/s40562-019-0149-8 ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 4

Author(s):

Mohammad Heidarzadeh ◽

Yuchen Wang ◽

Kenji Satake ◽

Iyan E. Mulia

Keyword(s):

Data Assimilation ◽

Warning System ◽

Western Mediterranean ◽

Tsunami Warning ◽

Sensitivity Analyses ◽

Bottom Pressure ◽

Tsunami Warning System ◽

Earthquake Scenarios ◽

The North ◽

Western Mediterranean Basin

AbstractWestern Mediterranean Basin (WMB) is among tsunamigenic zones with numerous historical records of tsunami damage and deaths. Most recently, a moderate tsunami on 21 May 2003 offshore Algeria, North Africa, was a fresh call for strengthening tsunami warning capabilities in this enclosed water basin. Here, we propose to deploy offshore bottom pressure gauges (OBPGs) and to adopt the framework of a tsunami data assimilation (TDA) approach for providing timely tsunami forecasts. We demonstrate the potential enhancement of the tsunami warning system through the case study of the 2003 Algeria tsunami. Four scenarios of OBPG arrangements involving 10, 5, 3 and 2 gauges are considered. The offshore gauges are located at distances of 120–300 km from the North African coast. The warning lead times are 20, 30, 48 and 55 min for four points of interest considered in this study: Ibiza, Palma, Sant Antoni and Barcelona, respectively. The forecast accuracies are in the range of 69–85% for the four OBPG scenarios revealing acceptable accuracies for tsunami warnings. We conclude that installation of OBPGs in the WMB can be helpful for providing successful and timely tsunami forecasts. We note that the OBPG scenarios proposed in this study are applicable only for the case of the 2003 Algeria tsunami. Further studies including sensitivity analyses (e.g., number of OBPG stations; earthquake magnitude, strike, epicenter) are required in order to determine OBPG arrangements that could be useful for various earthquake scenarios in the WMB.

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Getting Tsunami Recovery and Early Warning Right

Open House International ◽

10.1108/ohi-01-2006-b0007 ◽

2006 ◽

Vol 31 (1) ◽

pp. 54-61

Author(s):

Ben Wisner ◽

Peter Walker

Keyword(s):

Indian Ocean ◽

Early Warning ◽

Warning System ◽

Status Quo ◽

Indian Ocean Tsunami ◽

Tropical Storms ◽

Warning Systems ◽

Tsunami Warning System ◽

Policy Makers ◽

The Status

The massive human and economic impact of the Asian tsunami in later 2004 is mirrored in the aftershocks felt among humanitarian organisations, development agencies, and policy makers. This paper raises a number of these troubling, fundamental issues. Firstly, the call for an Indian Ocean tsunami warning system raises fundamental issues about what warning systems can, and cannot, do. Secondly, one is also forced to consider why in the first place so many people live on exposed coasts today, vulnerable not only to tsunamis but tropical storms and rainy season flooding among other hazards. Thirdly, one is challenged to question the very meaning of “recovery”. Such massive damage has been done and so many people and their livelihoods have been dislocated, is it actually possible to imagine a return to the status quo ante? Fourthly, reconstruction of the magnitude now underway in the affected areas raises many difficult questions about accountability, transparency, and the unevenness with which the international community responds to crises. The paper finishes with some recommendations.

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