This report has described the impact on Onslow from a tsunami generated by a Mw 9 earthquake on the Sunda Arc subduction zone occurring at Highest Astronomical Tide, Lowest Astronomical Tide and Mean Sea Level. There is no knowledge of the return period for this event. The modelling methodology, assumptions and data sources for the Onslow scenario have also been described. As discussed in Section \ref{sec:issues}, it is imperative that the best available data is used to increase confidence in the inundation maps. An onshore grid resolution of the order of tens of metres is required, however, it is more important that the data are accurate (or at least well known). These scenarios will be revisited once the probabilistic models are complete so that a suite of tsunami impact assessments can be made. Future activities to support the impact studies on the North West Shelf include: \begin{itemize} \item Sourcing of data sets, \item Investigation of solution sensitivity to cell resolution, bathymetry and tsunami source uncertainties, \item Location of boundary for simulation study area, and \item Investigation of friction coefficients. \end{itemize}