Potential inundation of Lisbon downtown by a 1755-like tsunami

Abstract

Abstract. In this study, we present 10 m resolution tsunami flooding maps for Lisbon downtown and the Tagus estuary.To compute these maps we use the present bathymetry and topographic maps and a reasonable estimate for the maximum credible tsunami scenario. Tsunami modeling was made with a non-linear shallow water model using four levels of nested grids. The tsunami flood is discussed in terms of flow depth, run-up height and maximum inundation area. The results show that, even today, in spite of the significant morphologic changes in the city river front after the 1755 earthquake, a similar event would cause tsunami flow depths larger than one meter in a large area along the Tagus estuary and Lisbon downtown. Other areas along the estuary with a high population density would also be strongly affected. The impact of the tide on the extent of tsunami inundation is discussed, due to the large amplitude range of the tide in Lisbon, and compared with the historical descriptions of the 1755 event. The results presented here can be used to identify the potential tsunami inundation areas in Lisbon; this identification comprises a key element of the Portuguese tsunami emergency management system.

Performance of coastal sea-defense infrastructure at El Jadida (Morocco) against tsunami threat: lessons learned from the Japanese 11 March 2011 tsunami

“…Benchmarking results show good performances of the numerical code for various tests. Also, this code has been successfully used to simulate various historical tsunamis, such as the 1755 Lisbon event (Baptista et al, 2011a), and recent events, such as the 2004 Sumatra tsunami (Wijetunge, 2009), showing good agreements with observations. Simulated near-shore waves show differences in characteristics and behaviour between waves generated by the various tsunami scenarios considered in this study.…”

“…The tsunami hazard in the Gulf of Cadiz region, which is an important component of a TWS, is well established through the elaboration of the historical tsunami catalogs Kaabouben et al, 2009;Blanc, 2009), the definition of the tsunamigenic scenarios (Omira et al, 2009), the identification of tsunami deposits (Ruiz et al, 2005;Font et al, 2010;Medina et al, 2011;Costa et al, 2011), and the estimations of the waves' impact Lima et al, 2010;Baptista et al, 2011a). Moreover, major efforts have been addressed to enhance the seismic network to cover areas around the Azores-Gibraltar plate boundary, and in particular the Cadiz Gulf region.…”

“…In the Gulf of Cadiz coastal areas, various studies have been addressed to investigate tsunami impact (Lima et al, 2010;Omira et al, 2011;Baptista et al, 2011a), and the area's vulnerability . These works and this paper show the high level of destruction that coastal areas of Morocco, Portugal and Spain could experience following the occurrence of large regional tsunami events, and hence the need for robust TWS in the region to mitigate the tsunami hazard.…”

“…Therefore, for an adequate simulation of near-shore tsunami propagation and overland inundation at the site of interest, we employ the nonlinear SWEs including bottom friction. We use the adapted version COMCOT-Lx (Omira et al, 2009;Omira et al, 2010;Baptista et al, 2011a) of COMCOT code (Liu et al, 1998) to solve these equations numerically. This code employs a dynamically coupled system of nested grids and solves SWEs using an explicit staggered leap-frog finite differences R. Omira: Performance of sea-defense structures in Morocco against tsunamis numerical scheme for linear terms and an upwind scheme for the nonlinear terms (Wang, 2009).…”

Tsunami hazard and buildings vulnerability along the Northern Atlantic coast of Morocco –the 1755-like tsunami in Asilah test-site

“…Hazard and vulnerability are the main components of any comprehensive risk assessment. For the tsunami phenomenon, the hazard assessment along a threatened coast is often covered by numerical modeling of the resulting inundations through the deterministic method (Tinti and Armigliato 2003;Tinti et al 2005;Løvholt et al 2006;Baptista et al 2011;Omira et al 2011;Omira et al 2013) or the probabilistic analysis (González et al 2009;Omira et al 2016). In addition, vulnerability study is trans-disciplinary and multi-dimensional, covering social, economic, physical, political, engineering and ecological aspects and dimensions (Post et al 2009).…”