From 1 - 10 / 102
  • The information within this document and associated DVD is intended to assist emergency managers in tsunami planning and preparation activities. The Attorney General's Department (AGD) has supported Geoscience Australia (GA) in developing a range of products to support the understanding of tsunami hazard through the Australian Tsunami Warning System Project. The work reported here is intended to further build the capacity of the Tasmanian State Government in developing inundation models for prioritised locations.

  • The Tsunami teaching resource comprises; - 36 page booklet that includes definitions and causes of tsunamis, how danger increases as tsunamis approach land and their frequency of occurrence in Australia. Also gives vital information on recognising and surviving a tsunami. - 3 reproducible student activities - suggested answers to student activities Suitable for secondary level Years 7-10.

  • The Attorney General's Department (AGD) has supported Geoscience Australia (GA) to develop inundation models for selected Northern Territory communities with the view of building the tsunami planning and preparation capacity of the Northern Territory Government. The communities chosen were Darwin, Palmerston, Wagait Beach and Dundee Beach. These locations were selected in collaboration with the Northern Territory Emergency Service (NTES) and Department of Natural Resources, Environment, The Arts and Sport (NRETAS) and the Australian Government based on a combination of the offshore Probabilistic Tsunami Hazard Assessment of Australia (PTHA)[1], the availability of suitable elevation data and the location of low lying communities. Three tsunamigenic events were selected for modelling from the scenario database that was calculated as part of the national offshore probabilistic tsunami hazard assessment (PTHA) [1]. The events selected are hypothetical and are based on the current understanding of the tsunami hazard. Only earthquake sources are considered as these account for the majority of tsunami. The suite of events includes three 'worst-case' or 1 in 10 000 year hazard events as well as more frequent events. Source zones considered are the Timor Trough, Flores-Wetar Thrust Fault and the Java Trench as these regions make the highest contribution to the offshore tsunami hazard for Darwin.

  • The aim of this document is to * outline the information management process for inundation modelling projects using ANUGA * outline the general process adopted by Geoscience Australia in modelling inundation using ANUGA * allow a future user to understand (a) how the input and output data has been stored (b) how the input data has been checked and/or manipulated before use (c) how the model has been checked for appropriateness

  • Pacific island countries face a tsunami threat that consists of a complex mix of tsunamis from local, regional and distant sources. Assessment of risk on these islands requires the ability to model tsunami inundation, and such modelling is complicated by the fact that they are often surrounded by shallow coral reef systems whose influence on tsunami propagation is poorly understood. These islands also suffer from a lack of both bathymetry and topography data of sufficient resolution to accurately model tsunami inundation. Geoscience Australia and the Pacific Islands Applied Geoscience Commission (SOPAC) have been developing a capacity for tsunami inundation modeling in support of risk assessment for Pacific islands that relies on remote sensing for nearshore bathymetric data coverage, including shallow reef platforms. This technique uses a physics-based modeling approach that estimates bathymetry from multispectral imagery, based on an optimisation driven per-pixel estimation of a set of environmental variables, including water column depth, from a semi-analytical expression of sub-surface remote sensing reflectance. Using this approach we have developed models for shallow bathymetry for off Nuku'alofa in Tongatapu and Gizo in the Solomon Islands, and merged these models with available swath bathymetry and global bathymetry data to produce bathymetry grids suitable for modelling tsunami inundation. We have attempted to validate these models against data for the 2006 Tonga (Mw=8.0) and 2007 Solomon Islands (MW=8.1) earthquakes, respectively.

  • Since the 2004 Sumatra-Andaman Earthquake, understanding the potential for tsunami impact on coastlines has become a high priority for Australia and other countries in the Asia-Pacific region. Tsunami warning systems have a need to rapidly assess the potential impact of specific events, and hazard assessments require an understanding of all potential events that might be of concern. Both of these needs can be addressed through numerical modelling, but there are often significant uncertainties associated with the three physical properties that culminate in tsunami impact: excitation, propagation and runup. This talk will focus on the first of these, and attempt to establish that seismic models of the tsunami source are adequate for rapidly and accurately establishing initial conditions for forecasting tsunami impacts at regional and teletsunami distances. Specifically, we derive fault slip models via inversion of teleseismic waveform data, and use these slip models to compute seafloor deformation that is used as the initial condition for tsunami propagation. The resulting tsunami waveforms are compared with observed waveforms recorded by ocean bottom pressure recorders (BPRs). We show that, at least for the large megathrust earthquakes that are the most frequent source of damaging tsunami, the open-ocean tsunami recorded by the BPRs are well predicted by the seismic source models. For smaller earthquakes, or those which occur on steeply dipping faults, however, the excitation and propagation of the resulting tsunami can be significantly influenced by 3D hydrodynamics and by dispersion, respectively. This makes it mode difficult to predict the tsunami waveforms.

  • The aim of this document is to provide the Fire and Emergency Services Authority of Western Australia (FESA) with a preliminary assessment of tsunami risk to a number of communities in South West WA. This assessment follows the preliminary assessment of tsunami impact for six North West Shelf communities and probabilistic tsunami hazard assessment for Western Australia which described the chance of a given tsunami wave height at the 50m contour being exceeded.

  • The aim of this document is to: * outline the general process adopted by Geoscience Australia in modelling tsunami inundation for a range of projects conducted in collaboration with Australian and State Government emergency management agencies * allow discoverability of all data used to generate the products for the collaborative projects as well as internal activities.

  • In this paper a new benchmark for tsunami model validation is pro- posed. The benchmark is based upon the 2004 Indian Ocean tsunami, which provides a uniquely large amount of observational data for model comparison. Unlike the small number of existing benchmarks, the pro- posed test validates all three stages of tsunami evolution - generation, propagation and inundation. Specifically we use geodetic measurements of the Sumatra{Andaman earthquake to validate the tsunami source, al- timetry data from the jason satellite to test open ocean propagation, eye-witness accounts to assess near shore propagation and a detailed inundation survey of Patong Bay, Thailand to compare model and observed inundation. Furthermore we utilise this benchmark to further validate the hydrodynamic modelling tool anuga which is used to simulate the tsunami inundation. Important buildings and other structures were incorporated into the underlying computational mesh and shown to have a large inuence of inundation extent. Sensitivity analysis also showed that the model predictions are comparatively insensitive to large changes in friction and small perturbations in wave weight at the 100 m depth contour.