EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Open Access Open Access Nat. Hazards Earth Syst. Sci. Discuss.,Natural 1, 2127–2161, Hazards 2013 Natural Hazards www.nat-hazards-earth-syst-sci-discuss.net/1/2127/2013/ and Earth System doi:10.5194/nhessd-1-2127-2013and Earth System NHESSD Sciences Sciences © Author(s) 2013. CC Attribution 3.0 License. 1, 2127–2161, 2013 Discussions Open Access Open Access Atmospheric Atmospheric This discussion paper is/has been under review for the journal Natural Hazards and Earth Chemistry Chemistry Tsunami hazard System Sciences (NHESS). Please refer to the corresponding final paper in NHESS if available. and Physics and Physics assessment in El Discussions Salvador Open Access Open Access Tsunami hazardAtmospheric assessment inAtmospheric El J. A. Álvarez-Gómez Measurement Measurement et al. Salvador, CentralTechniques America, fromTechniques seismic Discussions Open Access sources through flooding numerical Open Access Title Page Biogeosciences Biogeosciences models Discussions Abstract Introduction 1,2 2 2 Open Access J. A. Álvarez-Gómez , Í. Aniel-Quiroga , O. Q. Gutiérrez-Gutiérrez , Open Access 3 2 3 3 2 Conclusions References J. Larreynaga , M. González , M.Climate Castro , F. Gavidia , I. Aguirre-AyerbeClimate , 2 4 P. González-Riancho , and E.of Carreñothe Past of the Past Tables Figures Discussions 1Department of Geodynamics, Faculty of Geology, Complutense University of Madrid, C/ José Open Access Open Access J I Antonio Novais, s/n, 28040 Madrid, Spain Earth System 2Environmental Hydraulics InstituteEarth “IHSystem Cantabria”, Universidad de Cantabria, C/ Isabel Torres Dynamics Dynamics J I no 15, Parque Científico y Tecnológico de Cantabria, 39011 Santander, SpainDiscussions 3 Department of Oceanography, General Directorate of Environmental Monitoring, Ministry of Back Close Open Access Environment and Natural Resources, C/ Las Mercedes, San Salvador, El Salvador Open Access 4 Geoscientific Geoscientific Full Screen / Esc Instituto Geográfico Nacional,Instrumentation C/ General Ibáñez Ibero, no 3, 28003Instrumentation Madrid, Spain Received: 3 January 2013 – Accepted:Methods 7 and May 2013 – Published: 17 MayMethods 2013 and Data Systems Data Systems Printer-friendly Version Correspondence to: J. A. Álvarez-Gómez ([email protected]) Discussions Open Access Open Access Interactive Discussion Geoscientific Published by Copernicus PublicationsGeoscientific on behalf of the European Geosciences Union. Model Development Model Development2127 Discussions Open Access Open Access Hydrology and Hydrology and Earth System Earth System Sciences Sciences Discussions Open Access Open Access Ocean Science Ocean Science Discussions Open Access Open Access Solid Earth Solid Earth Discussions Open Access Open Access The Cryosphere The Cryosphere Discussions Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Abstract NHESSD El Salvador is the smallest and most densely populated country in Central America; its coast has approximately a length of 320 km, 29 municipalities and more than 700 000 1, 2127–2161, 2013 inhabitants. In El Salvador there have been 15 recorded tsunamis between 1859 and 5 2012, 3 of them causing damages and hundreds of victims. The hazard assessment is Tsunami hazard commonly based on propagation numerical models for earthquake-generated tsunamis assessment in El and can be approached from both Probabilistic and Deterministic Methods. A determin- Salvador istic approximation has been applied in this study as it provides essential information for coastal planning and management. The objective of the research was twofold, on J. A. Álvarez-Gómez 10 the one hand the characterization of the threat over the entire coast of El Salvador, et al. and on the other the computation of flooding maps for the three main localities of the Salvadorian coast. For the latter we developed high resolution flooding models. For the former, due to the extension of the coastal area, we computed maximum eleva- Title Page tion maps and from the elevation in the near-shore we computed an estimation of Abstract Introduction 15 the run-up and the flooded area using empirical relations. We have considered local sources located in the Middle America Trench, characterized seismotectonically, and Conclusions References distant sources in the rest of Pacific basin, using historical and recent earthquakes and Tables Figures tsunamis. We used a hybrid finite differences – finite volumes numerical model in this work, based on the Linear and Non-linear Shallow Water Equations, to simulate a to- J I 20 tal of 24 earthquake generated tsunami scenarios. In the western Salvadorian coast, run-up values higher than 5 m are common, while in the eastern area, approximately J I from La Libertad to the Gulf of Fonseca, the run-up values are lower. The more ex- posed areas to flooding are the lowlands in the Lempa River delta and the Barra de Back Close Santiago Western Plains. The results of the empirical approximation used for the whole Full Screen / Esc 25 country are similar to the results obtained with the high resolution numerical modelling, being a good and fast approximation to obtain preliminary tsunami hazard estimations. Printer-friendly Version In Acajutla and La Libertad, both important tourism centres being actively developed, flooding depths between 2 and 4 m are frequent, accompanied with high and very high Interactive Discussion 2128 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | person instability hazard. Inside the Gulf of Fonseca the impact of the waves is almost negligible. NHESSD 1, 2127–2161, 2013 1 Introduction Tsunami hazard Tsunamis are a relatively infrequent phenomena representing a greater threat than assessment in El 5 earthquakes, hurricanes and tornadoes, and causing since 1850 the loss of more than Salvador 420 000 human lives and extensive damage to coastal infrastructure around the world. Advances in the understanding and forecasting of tsunami impacts allow the develop- J. A. Álvarez-Gómez ment of adaptation and mitigation strategies to reduce risk on coastal areas. et al. El Salvador is the smallest and most densely populated country in Central Amer- 2 10 ica. Its area covers 21 393 km and its population reaches 5 580 000 inhabitants (DI- GESTYC, 2007). The coast of El Salvador has approximately a length of 320 km, with Title Page 29 municipalities along its shore and habited by more than 700 000 people. The coun- try is located in an area with a high seismic activity, where earthquakes, landslides and Abstract Introduction mudslides are considered major natural hazards. Conclusions References 15 In El Salvador there have been 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages. On 26 February of 1902 an earthquake near the coast Tables Figures of Guatemala and El Salvador generated a tsunami which flooded the coast along Ahuachapán and La Paz causing the death of 185 inhabitants. On 10 March of 1957 J I a tsunami reached the coast of Acajutla due to the MW = 8.1 Alaska earthquake. The J I 20 tsunami caused damage in the Port of Acajutla which was in construction at that mo- ment, causing loss of lives (Fernández, 2002). The most recent was on 27 August Back Close 2012, a MW = 7.3 earthquake generated a small tsunami that affected the area of the Peninsula of San Juan Del Gozo, in the Jiquilisco Bay, causing damage in some in- Full Screen / Esc frastructure and several injured people who were working at that moment in the turtle Printer-friendly Version 25 hatcheries located near the beach. The hazard assessment is commonly based on propagation numerical mod- Interactive Discussion els for earthquake-generated tsunamis. This models are developed through the 2129 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | characterization of the tsunamigenic seismic sources (faults) and the numerical mod- elling of the tsunami wave propagation and, if needed, flooding. Tsunami hazard as- NHESSD sessment can be approached by both Probabilistic (PTHA) and Deterministic Methods. 1, 2127–2161, 2013 When PTHA is performed, it is often considered as an extension of Probabilistic Seis- 5 mic Hazard Assessment (PSHA) (Annaka et al., 2007; Burbidge et al., 2008; González et al., 2009; Grezio et al., 2010; Sørensen et al., 2012; Power et al., 2012), obtaining Tsunami hazard seismic return periods for potential tsunamigenic earthquakes and incorporating the assessment in El aleatory uncertainties on the fault and tidal level parameters. Salvador Deterministic analyses are based on worst-case scenarios, where the maximum po- J. A. Álvarez-Gómez 10 tential tsunamigenic earthquakes are simulated. In addition, aggregated analysis com- bining the results obtained for a number of worst-case scenarios of tsunamis in an area et al. can be done. A deterministic approximation has been applied in this study. This approx- imation provides essential information for coastal planning, engineering and manage- Title Page ment in terms of security concerns (Tinti and Armigliato, 2003). 15 Simulations of historical and potential tsunamis with greater or lesser impact to the Abstract Introduction country’s coast have been developed, including distant, intermediate and near sources. 24 scenarios of different seismic sources have been generated. The result is a cat- Conclusions References