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 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.

Geoscience Australia (GA) is currently undertaking a process of revising the Australian National Earthquake Hazard Map using modern methods and an updated catalogue of Australian earthquakes. This map is a key component of Australia's earthquake loading standard, AS1170.4. Here we present an overview of work being undertaken within the GA Earthquake Hazard Project and how it contributes to the next generation earthquake hazard map. Fundamental to any Probabilistic Seismic Hazard Assessment (PSHA) is knowledge of the recurrence and maximum magnitude of historic and pre-historic earthquakes. Palaeoseismological investigation of neotectonic features observed in the Australian landscape has lead to the development of a catalogue, from which we have derived a domains model to characterise the occurrence and style of seismicity for large intraplate earthquakes. The domains model suggests that earthquakes ranging between MW 7.0-7.5±0.2 can occur anywhere across the continent. In addition to gathering information on the pre-historic record, more rigorous statistical analyses of the spatial distribution of the historic catalogue are also being undertaken. Earthquake magnitudes in Australian catalogues were determined using disparate magnitude formulae, with many local magnitudes determined using Richter attenuation coefficients prior to about 1990. Consequently, efforts are underway to standardise magnitudes for specific regions and temporal periods. Finally, we will review the general procedure for updating the national earthquake hazard map, including consideration of Australian-specific ground-motion prediction equations. We will also examine the sensitivity of hazard estimates to the assumptions of certain model components in the hazard assessment.

Decision making on community, government and business vulnerability and risk requires a reliable understanding of the nature of the assets at risk. These include people, buildings, economic activity and critical infrastructure. Collectively they are termed 'exposure' and Geoscience Australia (GA) has developed a system which now defines a wide range of exposure types in a current and consistent way on a national scale. The capability is called the National Exposure Information System and is now widely known by the acronym NEXIS. This investment was prompted initially by the agency's own information needs, but more recently development resources have been supplemented with contributions made by other stakeholders to meet their information needs.

National Exposure Information System - Program for Brisbane 21-22 October 2010 Agenda

NEXIS Queensland Stakeholder Engagement Workshops Minutes Policy makers, researchers and asset managers attended the Queensland stakeholder engagement workshops to better understand the National Exposure Information System (NEXIS) and the benefits it currently provides. The workshop also provided the opportunity for participants to contribute towards the advancement of NEXIS by guiding the alignment of its development strategies to better meet their future needs.

Legacy product - no abstract available

The high risk of natural disasters in developing nations has considerable implications for international aid programs. Natural disasters can significantly compromise development progress and reduce the effectiveness of aid investments. In order to better understand the threat that natural disasters may pose to its development aid program, AusAID commissioned Geoscience Australia to conduct a broad natural hazard risk assessment of the Asia-Pacific region. The assessment included earthquake, volcanic eruption, tsunami, cyclone, flood, landslide and wildfire hazards, with particular attention given to countries the Australian Government considered to be of high priority to its development aid program. Geoscience Australia's preliminary natural hazard risk assessment of the region aimed to help AusAID identify countries and areas at high risk from one or more natural hazards. The frequency of a range of sudden-onset natural hazards was estimated and, allowing for data constraints, an evaluation was made of potential disaster impact. Extra emphasis was placed on relatively rare but high-impact events, such as the December 2004 tsunami, which might not be well documented in the historical record. While a detailed risk assessment was well beyond the scope of this study, it was recognized that some understanding of the potential impact of natural disasters could be achieved through the simple means of developing appropriate overlays of population and hazard. For example, given an estimate of the frequency and magnitude (VEI) at which volcanic eruptions in a certain region occur, the populations impacted could be roughly estimated by considering the average population close enough to a volcano to receive a significant impact from ash fall.

To achieve the RELACS Program's aim of improving the capabilities of the Rabaul Volcanological Observatory to locate and interpret volcano-related earthquake activity near Rabaul, a program of seismic field observation was undertaken in the Rabaul area by a consortium of institutions with significant experience in seismic work, viz AGSO, ANU, and the Universities of Hokkaido and Wisconsin. This Record describes post survey data processing of RELACS field data undertaken at the ANU, the University of Hokkaido and AGSO 1998-99. It also includes CDs of data files containing information on seismic recording stations, seismic shots, some earthquake locations, the arrival times of seismic waves, and seismic record files from stations in the international SUDS format.

The Sydney Basin encloses a significant proportion of the Australian population, and the 1989 M5.6 Newcastle earthquake demonstrated that the basin is not immune from the impact of even relatively modest earthquakes. In spite of this, few investigations have been conducted to identify and characterise potential geologic sources of strong ground shaking. A recent major study of the southern part of the basin commented that - The available data are less complete than ideal for the purposes of probabilistic seismic hazard analysis. - Essentially, the extreme infrequency of large earthquake events in intraplate regions, such as Australia, means that the short historic record of seismicity is poorly suited to the task of assessing seismic hazard. Hence, geologic, geomorphic and paleoseismic knowledge has a vital role to play in obtaining constraint on the probable location and recurrence of large and damaging earthquakes near Sydney. In April 2005 a one day workshop at the University of Sydney brought together a diverse range of researchers with experience in the geology and geomorphology of the Sydney Basin, neotectonics and seismic hazard science. A series of seminars were presented covering geology, geomorphology, seismicity and seismic hazard. These served as a nucleation point for subsequent discussion, and the drafting of the papers presented herein. This proceedings volume contains within its covers tools for understanding large earthquake occurrence within the Sydney Basin and compiles 12 papers addressing landscape and structural developement, and seismic hazard aspects, of the Lapstone Structural Complex west of Sydney. Hence, it represents a framework upon which future advances in our understanding of the seismic hazard posed to Australia's largest population centre may be based.