The development of the Indian Ocean Tsunami Warning and mitigation System (IOTWS) has occurred rapidly over the past few years and there are now a number of centres that perform tsunami modelling within the Indian Ocean, both for risk assessment and for the provision of forecasts and warnings. The aim of this work is to determine to what extent event-specific tsunami forecasts from different numerical forecast systems differ. This will have implications for the inter-operability of the IOTWS. Forecasts from eight separate tsunami forecast systems are considered. Eight hypothetical earthquake scenarios within the Indian Ocean and ten output points at a range of depths were defined. Each forecast centre provided, where possible, time series of sea-level elevation for each of the scenarios at each location. Comparison of the resulting time series shows that the main details of the tsunami forecast, such as arrival times and characteristics of the leading waves are similar. However, there is considerable variability in the value of the maximum amplitude (hmax) for each event and on average, the standard deviation of hmax is approximately 70% of the mean. This variability is likely due to differences in the implementations of the forecast systems, such as different numerical models, specification of initial conditions, bathymetry datasets, etc. The results suggest that it is possible that tsunami forecasts and advisories from different centres for a particular event may conflict with each other. This represents the range of uncertainty that exists in the real-time situation.

We present the first national probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment considers tsunami generated from near-field earthquakes sources around Indonesia as well as regional and far-field sources, to define the tsunami hazard at the coastline. The PTHA methodology is based on the established stochastic event-based approach to probabilistic seismic hazard assessment (PSHA) and has been adapted to tsunami. The earthquake source information is primarily based on the recent Indonesian National Seismic Hazard Map and included a consensus-workshop with Indonesia's leading tsunami and earthquake scientists to finalize the seismic source models and logic trees to include epistemic uncertainty. Results are presented in the form of tsunami hazard maps showing the expected tsunami height at the coast for a given return period, and also as tsunami probability maps, showing the probability of exceeding a tsunami height of 0.5m and 3.0m at the coast. These heights define the thresholds for different tsunami warning levels in the Indonesian Tsunami Early Warning System (Ina-TEWS). The results show that for short return periods (100 years) the highest tsunami hazard is the west coast of Sumatra, the islands of Nias and Mentawai. For longer return periods (>500 years), the tsunami hazard in Eastern Indonesia (north Papua, north Sulawesi) is nearly as high as that along the Sunda Arc. A sensitivity analysis of input parameters is conducted by sampling branches of the logic tree using a monte-carlo approach to constrain the relative importance of each input parameter. These results can be used to underpin evidence-based decision making by disaster managers to prioritize tsunami mitigation such as developing detailed inundation simulations for evacuation planning.

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 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 QLD State Government in developing inundation models for prioritised locations. Internally stored data /nas/cds/internal/hazard_events/sudden_onset_hazards/tsunami_inundation/gold_coast/gold_coast_tsunami_scenario_2009

The Attorney-General's Department (AGD) has supported Geoscience Australia (GA) to develop inundation models for four Victorian communities with the view of enhancing the tsunami planning and preparation capacity of the Victorian State Government. The four communities chosen were Lakes Entrance, Port Fairy, Portland, and Warrnambool. These locations were selected in collaboration with the Victorian State Emergency Service (SES) and the Australian Government, based on an initial review of low lying coastal communities, and an Australia wide nearshore tsunami hazard assessment [1]. Several tsunamigenic events were selected for modelling from the scenario database that was calculated as part of the national offshore probabilistic tsunami hazard assessment (PTHA) [2]. The events selected are hypothetical and are based on the current understanding of the tsunami hazard. Only earthquake sources are considered, which account for the majority of tsunami. The suite of events includes 'worst-case' or 1 in 10000 year hazard events, as well as a more frequent (1 in 100 and 1 in 500 year hazard) events. Source zones considered are the Puysegur Trench (all cases), the New Hebrides Trench and the Kermadec Trench (Lakes Entrance only), and the Java Trench and the South Sandwich Islands Trench (Port Fairy, Portland, and Warrnambool only). Based on the probabilistic tsunami hazard assessment [2], these source zones are considered as they make the most significant contributions to the offshore tsunami hazard for the study sites.

We present the first national probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment considers tsunami generated from earthquakes near-field sources around Indonesia as well as regional and far-field sources, to define the tsunami hazard at the coastline. The methodology is based on the established monte-carlo approach to probabilistic seismic hazard assessment (PSHA) and has been adapted to tsunami. The earthquake source information is primarily based on the recent Indonesian National Seismic Hazard Map developed by Team-9 and included a consensus-workshop with Indonesia's leading tsunami and earthquake scientists to finalise the input parameters. Results are presented in the form of tsunami hazard maps showing the expected tsunami height at the coast for a given return period (100, 500 and 2500 years) , and also as tsunami probability maps showing the probability of exceeding 0.5m and 3.0m at the coast, which define the thresholds for different tsunami warning levels in the Indonesian Tsunami Early Warning System (Ina-TEWS).

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 major tsunamis of the last few years have dramatically raised awareness of the possibility of potentially damaging tsunami reaching the shores of Australia and to the other countries in the region. Here we present three probabilistic hazard assessments for tsunami generated by megathrust earthquakes in the Indian, Pacific and southern Atlantic Oceans. One of the assessments was done for Australia, one covered the island nations in the Southwest Pacific and one was for all the countries surrounding the Indian Ocean Basin

The Mwp method provides a rapid estimate of the moment magnitude of an earthquake based on the P-wave arrival. In this paper we present a variation of this method that addresses two problems that are encountered when applying this method in practice. The first is that the magnitude of very large earthquakes that could generate an ocean wide tsunami is generally underestimated. The second is that the method relies on the magnitude of the first significant maximum after the P-arrival in the integrated displacement (ID) seismogram. Identification of the "correct" first maximum generally has to be performed by an analyst, which introduces a subjective step in the algorithm. In this paper we present a variation of the Mwp method that estimates the asymptotic value of the ID caused by the P arrival, rather than the first maximum. Since asymptotic behaviour of the ID is never observed in practice because of seismic background noise, the new method is based on a comparison of the seismic noise signal before the arrival and the signal of the arrival itself. The new algorithm allows a fully automatic and unambiguous moment estimate. We apply the algorithm to observations of 30 strong (Mw>6.0) earthquakes around Australia, and compare the result with the moment magnitudes of these earthquakes as published by the USGS. It is found that the new algorithm is more accurate than the standard Mwp method, especially for very large (Mw>7.5) earthquakes.

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.