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Historical data indicate that the Middle America subduction zone represents the primary tsunamigenic source that affects the Central American coastal areas. In recent years, the tsunami potential in the region has mainly been assessed using maximum credible earthquakes or historical events showing moderate tsunami potential. However, such deterministic scenarios are not provided with their adequate probability of occurrence. In this study, earthquake rates have been combined with tsunami numerical modeling in order to assess probabilistic tsunami hazard posed by local and regional seismic sources. The common conceptual framework for the probabilistic seismic hazard assessment has been adapted to estimate the probabilities of exceeding certain tsunami amplitudes along the Central American Pacific coast. The study area encompasses seismic sources related to the Central America, Colombia and Ecuador subduction zones. In addition to the classical subduction inter-plate events, this study also incorporates sources at the outer rise, within the Caribbean crust as well as intra-slab sources. The study yields conclusive remarks showing that the highest hazard is posed to northwestern Costa Rica, El Salvador and the Nicaraguan coast, southern Colombia and northern Ecuador. In most of the region it is 50 to 80% likely that the tsunami heights will exceed 2 m for the 500 year time exposure (T). The lowest hazard appears to be in the inner part of the Fonseca Gulf, Honduras. We also show the large dependence of PTHA on model assumptions. While the approach taken in this study represents a thorough step forward in tsunami hazard assessment in the region, we also highlight that the integration of all possible uncertainties will be necessary to generate rigorous hazard models required for risk planning. [ABSTRACT FROM AUTHOR]

The RIESGOS Project (Multi-Risk Analysis And Information System Components for the Andes Region) funded by the German Ministry of Science and education (BMBF) has, as one of its main goals, the design and development of distributed software components for multi-hazard and risk analysis in particular by simulating hypothetical future high-impact events and their consequences. Implemented as an open library of interacting Web-services, these components will cover a full range of multi-hazard and risk related data acquisition and simulation services. These services include, for example: query of a seismic catalog, simulation of a shake map, simulation of a tsunami inundation scenario and assessment of expected damage and loss under consideration of cascading effects to critical infrastructure. Individual Web-services can be flexibly combined to produce multi-hazard scenarios with the ultimate goal to assist local authorities and decision makers to explore factors influencing the risk in their specific multi-hazard environments, thus improving disaster risk reduction and disaster management activities.To facilitate the development of a project which encompasses diverse hazard and risk components of various nature, our research is organized along a set of pre-described 'event stories' representing realistic, complex multi-hazard events with cascading effects in selected pilot regions of Chile, Peru and Ecuador. For each story, a storyboard is developed, which provides a narrative description of a hypothetical crisis evolution, defines the specific hazards involved, the related exposed assets and the expected consequences. In particular, these event stories target the following topics: - earthquake and tsunami (Chile and Peru); - heavy rain and river flooding (Peru); - volcano instability, lahar event and subsequent flooding via temporary river blockage (Ecuador). Each story can then be analysed in a more quantitative way by estimating different scenarios through numerical analysis and simulation of the different risk components. Remarkably, the consideration of vulnerability in a multi-hazard risk assessment framework is significantly more challenging with respect to the single hazard case, especially when interaction may occur at the vulnerability level due to physical damage accumulation. Furthermore, the project also aims at considering cascading effects to critical infrastructure such as power grids, roads and bridges. In order to ease up the visual exploration of such a complex multi-risk framework, a Web-based demonstrator platform integrating decentralized OGC Web Processing Service instances into multi-hazard and risk scenarios is being developed. To better meet the requirements of end-users, a thorough analysis of users' needs and continued user participation during the whole development process is assured. [ABSTRACT FROM AUTHOR]