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Abstract: Laboratory experiments are conducted in a wave facility with a loose sediment beach in order to estimate the wave characteristics needed for sediment transport modeling. A roller model and a Boussinesq-type model are used for comparing and discussing the experimental results. It is shown that the velocity skewness and acceleration skewness evolutions along the beach profile can be estimated from measurements of surface elevations. The roller model correctly reproduces the set-up and undertow measurements as long as the cross-shore variations of the second-order moment of the free surface displacement are taken into account. The Boussinesq model correctly reproduces the wave non-linearities with some discrepancies in the breaking region over the bar topography. [Copyright &y& Elsevier]

Tsunami simulation software is a key component of state-of-the-art early warning systems but the inherent complexities in phases of installation, execution, pre and post-processing prevent their use in other areas of risk management such as communication and education. Recent advances in software and computational capacities such as the efficiency of GPU computing and the ubiquity of web browsers bring new opportunities to bridge the gap between expert and non-expert users. Here we present a Javascript library to enable a web browser to facilitate gathering and analyzing data from tsunami simulations, by means of interactive and efficient visualizations. At its core, the library uses WebGL, the browser's standard 3D graphics API, to run GPU accelerated computations of a tsunami model. A far-field tsunami model is implemented (linear shallow water equations discretized on spherical coordinates), and its implementation is validated against real tsunami observations, and benchmarked with two other tsunami software-packages. Two software platforms that use this library are presented to illustrate the powerful applications that can be developed for risk communication and education. These applications are characterized by their interactivity and fast computations, which enable users to focus on the understanding of the phenomena of tsunami propagation and iterate quickly to assess different scenarios and potential implications to tsunami risk management. Some limitations on this approach are discussed, in aspects such as scalability, performance, multi-threading and batch-processing, that can be relevant for other users. In our experience, the before mentioned benefits very well compensate the discussed limitations for this kind of applications. The library has an open source license, and is meant to be imported without modifying its source code to facilitate the creation of new applications as the ones herein presented. • BROWNI is a WebGL - Javascript tsunami simulation library. • Simulations run on web browsers "out of the box" making users more proficient. • Comparison with measurements and other simulators verify its accuracy. • Scientific outreach and risk communication software made with BROWNI are described. • Software and hardware limitations are discussed. [ABSTRACT FROM AUTHOR]

Abstract The feasibility of a tidal plant is assessed by studying the stream velocities, the hydrodynamic impacts and disturbances in the marine environment. However, as these technologies approach a commercial stage, it is important to assess the feasibility of injecting energy into the grid in a cost-effective way. Finding available transmission infrastructure and capacity is now one of the main barriers for renewable energy development. In this paper we assess the power potential of the Chilean Chacao channel and model the power evacuation impacts on the electric grid of the surrounding area in order to assess whether tidal plants in such isolated area are technical and economically feasible. Data obtained from direct measurement and hydrodynamic simulations is used to evaluate the electric power available through one year. The injection of power is simulated using a nested Newton-Raphson power flow solver that gives voltage and power flow changes as the tides evolve considering the characteristics of the grid. We found that a pilot project of 2.4 MW can produce 11.2 GWh per year, injecting in a 23 kV line. The region can integrate 7.4 MW without significant impact. Beyond this capacity, expensive reinforcement along the transmission system is needed. Highlights • A numerical assessment of the power extraction potential of the Chilean Chacao channel is presented. • The model uses data from direct measurements and classic harmonic analysis. • Interconnection alternatives for three tidal farms where designed and analyzed. • The power flow and voltage levels of the grid were assessed with a nested Newton-Raphson algorithm. • The neighboring electric grid can successfully interconnect a 8.4 MW tidal farm. Bigger farms impact significantly the grid. [ABSTRACT FROM AUTHOR]

• Study of a RC building subjected to earthquake and tsunami in sequence. • Synthetic and consistent earthquake and tsunami time histories were generated. • Complete nonlinear dynamic analysis considering soil structure interaction. • The response to the tsunami is not significantly affected by the previous earthquake. • The case of an aftershock simultaneous with the peak tsunami wave is critical. This research presents a methodology to study the behavior of buildings subjected to seismic and tsunami loading in sequence, considering soil structure interaction effects through a complete dynamic analysis. The case-study building is an RC frame, which is assumed to be located in a coastal city in Chile, and built on sandy soil. A 3D Soil-Structure Interaction (SSI) model, including the non-linear behavior of both the structure and the soil using finite element method (FEM) was presented. Synthetic seismic ground motion records and tsunami inundation time histories were generated, consistent with the same earthquake source. Building performance was first assessed considering the SSI model for each hazard separately and compared to a Fixed Base (FB) model. Then, the SSI model was subjected to seismic and tsunami loading in sequence. Engineering Demand Parameters (EDPs) of roof displacement, interstory drift ratio (IDR) and reinforcement strain in beams and columns were analyzed. These EDPs presented a larger response to the tsunami when the response to the previous earthquake was larger. Finally, two vertical evacuation building scenarios were studied: the location of the refugees and the effect of an aftershock occurring simultaneously with the tsunami inundation. Results showed that the location of the refugees did not generate significant differences in the building response, and the aftershock increased the response only when it coincided with the maximum tsunami force. [ABSTRACT FROM AUTHOR]

Abstract: To describe the strongly nonlinear dynamics of waves propagating in the final stages of shoaling and in the surf and swash zones, fully nonlinear models are required. The ability of the Serre or Green Naghdi (S–GN) equations to reproduce this nonlinear processes is reviewed. Two high-order methods for solving S–GN equations, based on Finite Volume approaches, are presented. The first one is based on a quasi-conservative form of the S–GN equations, and the second on a hybrid Finite Volume/Finite Difference method. We show the ability of these two approaches to accurately simulate nonlinear shoaling, breaking and runup processes. [Copyright &y& Elsevier]