Probabilistic seismic hazard analyses in Australia rely fundamentally on the assumption that earthquakes recorded in the past are indicative of where earthquakes will occur in the future. No attempt has yet been made to assess the potential contribution that data from active fault sources might make to the modelling process, despite successful incorporation of such data into United States and New Zealand hazard maps in recent years. In this paper we review the limited history of paleoseismological investigation in Australia and discuss the potential contribution of active fault source data towards improving our understanding of intraplate seismicity. The availability and suitability of Australian active fault source data for incorporation into future probabilistic hazard models is assessed, and appropriate methodologies for achieving this proposed.

GPR data have been collected across confirmed palaeofault scarps at Hyden and Dumbelyung, and also the scarp created by the 1968 Meckering earthquake. In each case there is a nearby trench to allow GPR responses to be related to known geology. At Meckering and Hyden, where the near-surface material contains moderate amounts of clay and the groundwater is fresh, it has proved possible to collect high quality data that images colluvium and also disrupted bedrock features which allow faults to be inferred. At Dumbelyung, where the near surface is more conductive due to clay-rich alluvial deposits and saline groundwater, results were poor and no sub-surface features were confidently identified. Our results demonstrate that, subject to the satisfaction of a predictable set of ground conditions, GPR surveys are a valuable tool for studying palaeofaults in deeply weathered terrains. The results provide sufficient information to confirm a topographic feature is of seismic origin, and to aid in siting trenches for palaeoseismic studies.

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

A 'shake-map' represents the spatial distribution of macroseismic intensity resulting from an earthquake. These maps are often used to determine potential humanitarian consequences from scenario earthquakes, or in near-real time following the detection of an event. In the absence of dense strong-motion networks to calibrate real-time ground-shaking in many of the most vulnerable regions of the world, shake-maps are commonly generated using either Intensity Prediction Equations (IPEs) or Ground-Motion Prediction Equations (GMPEs) combined with Ground-Motion to Intensity Conversion Equations (GMICEs). There are several empirical models available to estimate the spatial distribution of intensity for an earthquake of given magnitude and location. However, these models can predict very different estimates of shaking intensity given the same input parameters; particularly at near-source distance ranges - the most critical distances for impact assessments. Consequently, the application of different shaking hazard model inputs can result in significantly different impacts. High-dimensional information visualisation techniques are used to study the mutual differences among different empirical intensity prediction models. We applied the Self-Organising Map (SOM) technique to project empirical prediction models onto a two-dimensional 'map' to visually compare the similarities and differences between models. The results clearly demonstrate the sensitivity of ground shaking to the selection of intensity prediction models. The effects of these sensitivities on earthquake impact assessments are investigated using a scenario event in Sumatra region, Indonesia.

Probabilistic seismic hazard assessment (PSHA) is an important tool for reducing earthquake fatalities through land use planning, emergency management training based on credible earthquake scenarios, and improved building codes. The application of PSHA in Indonesia has seen rapid developmetn in the last few years, with development of a PSHA for Sumatra by Petersen et al. (2004), followed by PSHA of Java and Sumatra by Irsyam et al. (2008) and the most recent all-Indonesia PSHA developed by a group of Indonesian scientists known as "Team-9". These recent PSHA's for Indonesia show a generally increasing level of earthquake hazard, with the increase mainly associated with the new information avaialble on the earthquake activity of crustal faults, and, too a lesser extent, on intraslab earthquake activity. As part of a project to strengthen the Government of Indonesia's capacity to produce better PSHA's, we have used some of teh most recent information availble on earthquake activity and site response in the Indonesia province of Central Java. Our PSHA is implemented using an event-based approach to the calculation of seismic hazard, and it relised on geologic information on the slip rates of active crustal faults to define earthquake sources, and also on topography and surface geology informaiton to estimate site amplification. We will discuss our results in the context of extending its application to all of Indonesia.

This education resource comprises earthquake images with background information and descriptions of each image - includes world plate boundaries and earthquake distribution, distribution of earthquakes in Australia and examples of earthquake events, Australia's Seismological Network that is managed by Geoscience Australia, how earthquakes are measured, a case study of Tennant Creek and a map indicating Australia's earthquake hazard. Suitable for primary level Years 5-6 and secondary level Years 7-12.

Stress Tensor reconstructions are presented for seven domains withinthe Australian crust based on formal inversion of four or more earthquake focal mechanisms in close geographic proximity. The data for inversion was sourced from a set of sixty-nine quality-ranked focal mechanisms forming part of the recently compiled AGSO focal mechanism database. When analysed in conjunction with in situ stress data held by the Australian Stress Map project, the new data makes possible for the first time a rigorous comparison of the Australian continental stress field at near-surface and seismogenic depths. A more complete picture of the character of the Australian intraplate stress field is thereby made available. The tensor data agrees well with in situ determinations in western, northern and far southeastern Australia suggesting that the continental stress field is homogeneous between shallow and seismogenic depth in these areas. Plate boundary forces are considered to be the dominant source of stress. In contrast, the results for the Sydney Basin and Flinders Ranges imply significant heterogeneity and influence by more localised sources of stress.

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