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Accurate and efficient tsunami modelling is essential for providing tsunami forecasts and hazard assessments. Volna-OP2 is a finite volume solver of the nonlinear shallow water equations and its capabilities of producing both faster than real time ensembles and high resolution inundation studies are presented here. The code is massively parallelised and can utilise various high performance computing architectures. When an earthquake is detected there is always some uncertainty on the source parameters. Generating a faster than real time ensemble for maximum wave heights which captures this uncertainty would be of great benefit to tsunami warning centres. The 2003 Boumerdes earthquake (Algeria) acts as a test case for showing Volna-OP2's ability at rapidly forecasting regional maximum wave heights. Drawing on various earthquake sources proposed in the literature and scaling the magnitudes to mimic uncertainty on the source, 20 separate earthquake realisations are simulated for 4 hours real time in 97s on two Nvidia V100 GPUs. Further a reduced ensemble of the Lisbon 1755 tsunami with an emphasis on the effects to the Irish coastline is presented. Where again various earthquake sources have been drawn from the literature and simulated on a regional scale. Finally, a pilot study which builds upon the reduced ensemble results investigates the inundation of a Lisbon tsunami on key sections of the Irish coastline. The results of this pilot study highlight that the inundation is constrained to low-lying areas with maximum run-up heights of $\approx 3.4m$ being found.

In the vast literature on tsunami research, few articles have been devoted to energy issues. A theoretical investigation on the energy of waves generated by bottom motion is performed here. We start with the full incompressible Euler equations in the presence of a free surface and derive both dispersive and non-dispersive shallow-water equations with an energy equation. It is shown that dispersive effects only appear at higher order in the energy budget. Then we solve the Cauchy-Poisson problem of tsunami generation for the linearized water wave equations. Exchanges between potential and kinetic energies are clearly revealed., 20 pages, 12 figures. Accepted to Proceedings of the Royal Society A. Other authors papers and supporting material can be downloaded at http://www.lama.univ-savoie.fr/~dutykh

The present article is devoted to the influence of sediment layers on the process of tsunami generation. The main scope here is to demonstrate and especially quantify the effect of sedimentation on vertical displacements of the seabed due to an underwater earthquake. The fault is modelled as a Volterra-type dislocation in an elastic half-space. The elastodynamics equations are integrated with a finite element method. A comparison between two cases is performed. The first one corresponds to the classical situation of an elastic homogeneous and isotropic half-space, which is traditionally used for the generation of tsunamis. The second test case takes into account the presence of a sediment layer separating the oceanic column from the hard rock. Some important differences are revealed. We conjecture that deformations in the generation region may be amplified by sedimentary deposits, at least for some parameter values. The mechanism of amplification is studied through careful numerical simulations., 17 pages, 12 figures. Revised version for Computer Methods in Applied Mechanics and Engineering. Other author's papers can be downloaded from http://www.lama.univ-savoie.fr/~dutykh/

The classical theory of water waves is based on the theory of inviscid flows. However it is important to include viscous effects in some applications. Two models are proposed to add dissipative effects in the context of the Boussinesq equations, which include the effects of weak dispersion and nonlinearity in a shallow water framework. The dissipative Boussinesq equations are then integrated numerically., 40 pages, 15 figures, published in C. R. Mecanique 335 (2007) Other author's papers can be downloaded at http://www.cmla.ens-cachan.fr/~dutykh

Tsunamis are often generated by a moving sea bottom. This paper deals with the case where the tsunami source is an earthquake. The linearized water-wave equations are solved analytically for various sea bottom motions. Numerical results based on the analytical solutions are shown for the free-surface profiles, the horizontal and vertical velocities as well as the bottom pressure., 41 pages, 13 figures. Accepted for publication in a book: "Tsunami and Nonlinear Waves", Kundu, Anjan (Editor), Springer 2007, Approx. 325 p., 170 illus., Hardcover, ISBN: 978-3-540-71255-8, available: May 2007

The life of a tsunami is usually divided into three phases: the generation (tsunami source), the propagation and the inundation. Each phase is complex and often described separately. A brief description of each phase is given. Model problems are identified. Their formulation is given. While some of these problems can be solved analytically, most require numerical techniques. The inundation phase is less documented than the other phases. It is shown that methods based on Smoothed Particle Hydrodynamics (SPH) are particularly well-suited for the inundation phase. Directions for future research are outlined., 29 pages, 5 figures