The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

Basili, Roberto
Brizuela, Beatriz
Herrero, Andre
Iqbal, Sarfraz
Lorito, Stefano
Maesano, Francesco Emanuele
Murphy, Shane
Perfetti, Paolo
Romano, Fabrizio
Scala, Antonio
Selva, Jacopo
Taroni, Matteo
Tiberti, Mara Monica
Thio, Hong Kie
Tonini, Roberto
Volpe, Manuela
Glimsdal, Sylfest
Harbitz, Carl Bonnevie
Lovholt, Finn
Baptista, Maria Ana
Carrilho, Fernando
Matias, Luis Manuel
Omira, Rachid
Babeyko, Andrey
Hoechner, Andreas
Pekcan, Onur
Yalçıner, Ahmet Cevdet
Canals, Miquel
Lastras, Galderic
Agalos, Apostolos
Papadopoulos, Gerassimos
Triantafyllou, Ioanna
Benchekroun, Sabah
Agrebi Jaouadi, Hedi
Ben Abdallah, Samir
Bouallegue, Atef
Hamdi, Hassene
Oueslati, Foued
Amato, Alessandro
Armigliato, Alberto
Behrens, Joern
Davies, Gareth
Di Bucci, Daniela
Dolce, Mauro
Geist, Eric
Gonzalez Vida, Jose Manuel
Gonzalez, Mauricio
Macias Sanchez, Jorge
Meletti, Carlo
Ozer Sozdinler, Ceren
Pagani, Marco
Parsons, Tom
Polet, Jascha
Power, William
Sorensen, Mathilde
Zaytsev, Andrey
The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a threephase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models' weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (P01) distributed at an average spacing of -20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP approximate to 2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM1 8 results and documentation are available through the TSUMAPS-NEAM project website (, featuring an interactive web mapper. Although the NEAMTHM1 8 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning.
Citation Formats
R. Basili et al., “The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18),” pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: