Legacy product - no abstract available

The recently released ISC-GEM catalogue was a joint product of the International Seismological Center (ISC) and the Global Earthquake Model (GEM). In a major undertaking it collated, from a very wide range of sources, the surface and body wave amplitude-period pairs from the pre digital era; digital MS, mb and Mw; collated Mw values for 970 earthquakes not included in the Global CMT catalogue; used these values to determine new non-linear regression relationship between MS and Mw and mb and Mw. They also collated arrival picks, from a very wide range of sources, and used these to recompute the location, initially using the EHB location algorithm then revised using the ISC location algorithm (which primarily refined the depth). The resulting catalogues consists of 18871 events that have been relocated and assigned a direct or indirect estimate of Mw. Its completeness periods are, Ms - 7.5 since 1900, Ms - 6.25 1918 and Ms - 5.5 1960. This catalogue assigns, for the first time, an Mw estimate for several Australian earthquakes. For example the 1968 Meckering earthquake the original ML, mb and MS were 6.9, 6.1 and 6.8, with empirical estimates of Mw being 6.7 or 6.8. The ISC-GEM catalogue assigns an Mw of 6.5. We will present a poster of the Australian events in this ISC_GEM catalogue showing, where available, the original ML, mb, Ms, the recalculated mb and Ms, and the assigned Mw. We will discuss the implications of this work for significant Australian earthquakes.

Legacy product - no abstract available

Legacy product - no abstract available

The seismicity of the Australian continent is low to moderate by world standards. However, the seismic risk is much higher for some types of Australian infrastructure due to an incompatibility of structural vulnerability with local earthquake hazard. The earthquake risk in many regional neighbours is even higher due to high hazard, community exposure and vulnerability. The Risk and Impact Analysis Group is a multidisciplinary team at Geoscience Australia that is actively engaged in research to better understand earthquake risk in Australia and to assist agencies in neighbouring countries develop similar knowledge. In this presentation aspects of this work will be described with a particular focus on engineering vulnerability, post disaster information capture and how both can point to effective mitigation options. Risk is the combination of several components (hazard, exposure, vulnerability and impact) that combine to provide measures that can be very useful for decision makers. Vulnerability is the key link that translates hazard exposure to consequence. Vulnerability is typically expressed in physical terms but includes interdependent utility system vulnerability, economic activity vulnerability and the social vulnerability of communities. All four vulnerability types have been the subject of research at GA but the physical vulnerability is the primary link to the others. Vulnerability research for Australian infrastructure will be presented in the context of a holistic risk framework. Furthermore, the work in the Philippines to develop a first order national suite of models will also be presented. Post disaster survey data is invaluable for understanding the nature of asset vulnerability, developing empirical models and validating analytical models based on structural models. Geoscience Australia has developed a range of tools to assist with damage capture that have been used for several hazard types, including earthquake. Tools include portable street view imagery capture, GPS technology and hand-held computers. Experience with the application of these tools and the information that has been derived will be described along with current activity to improve their utility.

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

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.