# Changeset 7501

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Sep 9, 2009, 1:22:42 PM (11 years ago)
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 r7481 \section{Modelling the Event}\label{sec:models} Numerous models are currently used to model and predict tsunami generation, propagation and run-up. These range in solving different equations and employing different methodologies with some examples being~\cite{titov97a,satake95,zhang08}. Here we introduce the modelling methodology employed by Geoscience Australia to illustrate the utility of the proposed benchmark. The methodology used by Geoscience Australia has three distinct components. Firstly an appropriate model is used to approximate the initial sea surface deformation. This model is chosen according to the cause of the intial disturbance. The resulting wave is propagated using the \textsc{ursga} model (see Section~\ref{sec:ursga}) in the deep ocean until the wave reaches shallow water, typically the $100$ m depth contour. The ocean surface profile along this contour is used as a time varying boundary condition for the \textsc{anuga} model (see Section~\ref{sec:anuga}) which simulates the propagation of the tsunami within the shallow water and the subsequent inundation of the land. This three part methodology roughly follows the three stages of tsunami evolution. The components used to model each stage of evolution are described in more detail below. generation, propagation and run-up. These range in solving different equations and employing different methodologies with some examples being~\cite{titov97a,satake95,zhang08}. Here we introduce the modelling methodology employed by Geoscience Australia to illustrate the utility of the proposed benchmark. The methodology used by Geoscience Australia has three distinct components. Firstly an appropriate model is used to approximate the initial sea surface deformation. This model is chosen according to the cause of the intial disturbance. The resulting wave is propagated using the \textsc{ursga} model (see Section~\ref{sec:ursga}) in the deep ocean until the wave reaches shallow water, typically the $100$ m depth contour. The ocean surface profile along this contour is used as a time varying boundary condition for the \textsc{anuga} model (see Section~\ref{sec:anuga}) which simulates the propagation of the tsunami within the shallow water and the subsequent inundation of the land. This three part methodology roughly follows the three stages of tsunami evolution. The components used to model each stage of evolution are described in more detail below. \subsection{Generation}\label{sec:modelGeneration} co-seismic sea floor deformation. \textsc{ursga} is well suited to modelling propagation over large domains and is used to propagate the tsunami until it reaches shallow water, typically the $100$m depth contour. until it reaches shallow water, typically the $100$ m depth contour. %The propagation of the tsunami in shallow water ($<100$m) and inundation are modelled using a hydrodynamic package called \textsc{ursga}. This package is ideally suited to shallow water propagation and inundation as it accurately simulates flow over dry land and is based upon an irregular triangular grid which can be refined in areas of interest. Geoscience Australia tsunami modelling methodology is based on a hybrid approach using models like \textsc{ursga} for tsunami propagation up to an offshore depth contour, typically 100 m. propagation up to an offshore depth contour, typically $100$ m. %Specifically we use the \textsc{ursga} model to simulate the %propagation of the 2004 Indian Ocean tsunami in the deep ocean, based