Understanding disaster risk enables Government, industry and the community to make better decisions on how to prepare for disasters and improve the resilience of communities. Geoscience Australia develops and provides fundamental data and information to understand disaster risk so that we can determine how hazards impact the things that are valuable to us. Through robust and proven methodologies, technical expertise and trusted data, our national capability can support informed decisions to prepare for and respond to hazard events so that the impact of disasters can be reduced, and to inform where and how our future communities and supporting infrastructure are built.

Sites recording the extinction or extirpation of tropical–subtropical and cool–cold temperate rainforest genera during the Plio–Pleistocene aridification of Australia are scattered across the continent, with most preserving only partial records from either the Pliocene or Pleistocene. The highland Lake George basin is unique in accumulating sediment over c. 4 Ma although interpretation of the plant microfossil record is complicated by its size (950 km2), neotectonic activity and fluctuating water levels. A comparison of this and other sites confirms (1) the extinction of rainforest at Lake George was part of the retreat of Nothofagus-gymnosperm communities across Australia during the Plio–Pleistocene; (2) communities of warm- and cool-adapted rainforest genera growing under moderately warm-wet conditions in the Late Pliocene to Early Pleistocene have no modern analogues; (3) the final extirpation of rainforest taxa at Lake George occurred during the Middle Pleistocene; and (4) the role of local wildfires is unresolved although topography, and, elsewhere, possibly edaphic factors allowed temperate rainforest genera to persist long after these taxa became extinct or extirpated at low elevations across much of eastern Australia. Araucaria, which is now restricted to the subtropics–tropics in Australia, appears to have survived into Middle Pleistocene time at Lake George, although the reason remains unclear. <b>Citation:</b> Macphail Mike, Pillans Brad, Hope Geoff, Clark Dan (2020) Extirpations and extinctions: a plant microfossil-based history of the demise of rainforest and wet sclerophyll communities in the Lake George basin, Southern Tablelands of NSW, south-east Australia. <i>Australian Journal of Botany </i>68, 208-228.

You may not realise it but, on average, Australia is rattled every few days by an earthquake of magnitude 3 or above. We don’t feel every small tremor that happens, but the larger earthquakes are powerful enough to cause serious damage to buildings and infrastructure, putting our community’s safety at risk.

The 2018 National Seismic Hazard Assessment of Australia incorporated 19 alternative seismic-source models. The diversity of these models demonstrates the deep epistemic uncertainty that exists with regards to how best to characterize intraplate seismicity. A complex logic tree was developed to incorporate the alternative models into a single hazard model. Similarly, a diverse range of ground-motion models were proposed for use and incorporated using a logic tree. Expert opinion was drawn upon to weight the alternative logic tree branches through a structured expert elicitation process. This process aims to transparently and reproducibly characterize the community distribution of expert estimates for unknown parameters and thereby quantify the epistemic uncertainty around estimates of seismic hazard in Australia. We achieve a multi-model rational consensus where each model, and each expert, is, in accordance with the Australian cultural myth of egalitarianism, given a ‘fair go’. Yet despite this process, we find that the results are not universally accepted. A key issue is a contested boundary between what is scientifically reducible and what remains epistemologically uncertain, with a particular focus on the earthquake catalog. Furthermore, a reduction, on average, of 72% for the 10% in 50 years probability of exceedance peak ground acceleration levels compared with those underpinning existing building design standards, challenges the choice of metrics upon which design codes are based. As questions of epistemic uncertainty are quantified or resolved, changes in our understanding of how the hazard behaves should inform dialogue between scientists, engineers and policy makers, and a re-appraisal of the metrics used to inform risk management decisions of societal importance.

The Geological Survey of Western Australia, in collaboration with the Australian National University, Macquarie University, the Department of Fire and Emergency Services and Geoscience Australia has just installed the first seismometers of an array across the South West Seismic Zone of Western Australia. This region is one of the most seismically active areas of Australia having experienced over 2000 small (between ML 2 to 3) earthquakes since the year 2000. Many smaller events are also noted by the local people who often hear them coming. Yes – hear them coming – this area is known for its “noisy” earthquakes. Most of these earthquakes occur in swarms rather than main shock-aftershock sequences (Dent, 2015). This means that the region experiences a lot of small earthquakes, all much the same size and which occur in a similar area. These swarms can be active for years. The hazard associated with these seismic events is relatively small. However, in the past six decades this region has also hosted five of the nine surface rupturing earthquakes in Australia, most notably; Meckering (M 6.5) in 1968 from which there are photos of the bends in the railway lines (Fig 1a) and faulting of 2-3 m in height across the fields (Fig 1b) (Gordon and Lewis 1980; Johnston and White 2018, Clark and Edwards 2018); Calingiri (M5.9) in 1970 and Lake Muir (M5.6), which was felt by a lot of people across Western Australia just two years ago (Clark et al. 2020). Despite the high rates of seismicity, seismic monitoring in the region remains relatively sparse. To overcome this lack of instrumentation, the consortium of institutions mentioned above, came together for an ARC Linkage project to put in place a temporary network- the South West Australia Network (SWAN) - to improve the monitoring and detection capabilities in this area. This project will see a total of twenty-five broadband seismometers deployed across the Southwest of Western Australia for a period of approximately 2 years (Fig 2a and b). This temporary array will enable the detection and location of smaller-magnitude earthquakes which can be used to improve the crustal velocity models which in turn enables more accurate earthquake locations and helps the understanding of the crustal structure of this part of Australia. Better velocity models also enable better magnitude calculation methods, which improve the knowledge about recurrence of earthquakes of a certain magnitude. From a seismic hazard point of view, this data has the potential to assist in the development of improved methods for modelling how shaking intensity varies as it propagates through the earth’s crust from the earthquake source. Overall, this information will feed into an improved understanding of the earthquake hazard in the Southwest region of Western Australia. For local communities, it will provide an improved situational awareness following significant earthquakes. More broadly, the improved understanding of the seismicity of the Southwest of Western Australia will enhance emergency response capabilities, and inform building codes and mitigation initiatives, which are the best methods we have to minimise the earthquake risks to communities. Data will be released through AusPASS, the Australian Passive Seismic Server two years after the last data has been collected.

Economic analysis of natural hazards (wind, flood and storm surge) Australia wide. See more info in: http://www.garnautreview.org.au/

Survey conducted after the 2009 Victoria Bushfires.

Developing a framework and computational methodology for evaluating the impacts and risks of extreme fire events on regional and peri-urban populations (infrastructure and people) applicable to the Australian region. The research considers three case studies of recent extreme fires employing an ensemble approach (sensitivity analysis) which varies the meteorology, vegetation and ignition in an effort to estimate fire risk to the case-study fire area and adjacent region.

<p>Bushfires and Natural Hazards are features of the Australian climate and landscape. These hazards continue to pose threat and profound personal, social, economic and environmental impacts. In Disaster Risk Reduction (DRR), nationally consistent and comprehensive exposure information is critical to provide situational awareness and a fundamental baseline of what may be impacted for decision makers at all levels of governance. <p>Extensive consultation with stakeholders and a review of international exposure information practices has informed the compilation of information requirements for each phase of DRR. The Natural Hazards Exposure Information Framework is a definition of the data and attributes required for all levels of DRR governance in governments, insurance sector and researchers. The report reviewed current information provision systems in Australia, identified gaps and proposed recommendations to enable the creation of more comprehensive exposure information in the future. The framework is fundamentally based on the location of features in the physical environment and their characteristics including key social and economic attributes, e.g. insurance status, buildings, infrastructure (transport, energy, communications and water), people, businesses, manufacturing industries, hazardous substances, waste management and primary industries. Importantly, the framework also addresses the ‘fit for purpose’ question by describing guidelines for data custodians to establish and maintain data provenance to enable the derivation of meaningful data reliability measures for end users. <p>The Natural Hazards Exposure Information Framework provides guidance to build and advance exposure information systems in Australia. This will enable data custodians to prioritise and invest in data, processing and delivery to improve the efficiencies of both tactical and strategic disaster management. Improved nationally consistent and comprehensive exposure information will enable users to assess risk and provide informed advice, such as cost-benefit analysis of mitigation proposals or disaster recovery arrangements. This framework will be a fundamental reference in developing similar systems internationally such as Global Exposure Database for all hazards. The framework also aids in capacity building for developing nations to improve their DRR practices.

The Australian Flood Studies Database is available on line by Geoscience Australia via the Australian Flood Risk Information Portal. The database provides metadata on Australian flood studies and information on flood risk with a digital version where available. The purpose of the document is to guide new users in data entry and uploading of flood studies to a level acceptable for inclusion in the database.