The service contains the Australian Coastal Geomorphology Landform Subtype Classifications, used to support a national coastal risk assessment. It describes the location and extent of landform subtypes identifiable at scales between 1:25,000 and 1:10,000. It also provides further detail to the Landform Type, with particular reference to feature stability (e.g. dune types) and mobility (e.g. channel types).

The service contains the Australian Coastal Geomorphology Environments, used to support a national coastal risk assessment. It describes the location and extent primary geomorphological environments (both dispositional and erosional) present along the Australia coast and the processes acting on the features within.

This Geoscience Australia Record contains technical data and input files that, when used with the Global Earthquake Model’s (GEM’s) OpenQuake-engine probabilistic seismic hazard analysis software (Pagani et al., 2014), will enable end users to explore and reproduce the 2018 National Seismic Hazard Assessment (NSHA18) of Australia (Allen et al., 2018a). This report describes the NSHA18 input data only and does not discuss the scientific rationale behind the model development. These details are provided in Allen et al. (2018a) and references therein.

The service contains the Australian Coastal Geomorphology Scale Guide, used to support a national coastal risk assessment. It includes the extents of various reclassified costal mapping products.

Many mapped faults in the south-eastern highlands of New South Wales and Victoria are associated with apparently youthful topographic ranges, suggesting that active faulting may have played a role in shaping the modern landscape. This has been demonstrated to be the case for the Lake George Fault, ~25 km east of Canberra. The age of fluvial gravels displaced across the fault indicates that relief generation of approximately 250 m has occurred in the last ca. 4 Myr. This data implies a large average slip rate by stable continental region standards (~90 m/Myr assuming a 45 degree dipping fault), and begs the question of whether other faults associated with relief in the region support comparable activity rates. Preliminary results on the age of strath terraces on the Murrumbidgee River proximal to the Murrumbidgee Fault are consistent with tens of metres of fault activity in the last ca. 200 kyr. Further south, significant thicknesses of river gravels are over-thrust by basement rocks across the Tawonga Fault and Khancoban-Yellow Bog Fault. While these sediments remain undated, prominent knick-points in the longitudinal profiles of streams crossing these faults suggest Quaternary activity commensurate with that on the Lake George Fault. More than a dozen nearby faults with similar relief are uncharacterised. Recent seismic hazard assessments for large infrastructure projects concluded that the extant paleoseismic information is insufficient to meaningfully characterise the hazard relating to regional faults in the south-eastern highlands, despite the potential for large earthquakes alluded to above. While fault locations and extents remain inconsistent across scales of geologic mapping, and active fault lengths and slip rates remain largely unquantified, the same conclusion may be drawn for other scales of seismic hazard assessment.

<p>Geoscience Australia has recently released its 2018 National Seismic Hazard Assessment (NSHA18). Results from the NSHA18 indicate significantly lower seismic hazard across almost all Australian localities at the 1/500 annual exceedance probability level relative to the factors adopted for the current Australian Standard AS1170.4–2007 (R2018). These new hazard estimates, coupled with larger kp factors, have challenged notions of seismic hazard in Australia in terms of the recurrence of damaging ground motions. As a consequence, the new hazard estimates have raised questions over the appropriateness of the prescribed probability level used in the AS1170.4 to determine appropriate seismic demands for the design of ordinary-use structures. Therefore, it is suggested that the ground-motion exceedance probability used in the current AS1170.4 be reviewed in light of the recent hazard assessment and the expected performance of modern buildings for rarer ground motions. <p>Whilst adjusting the AS1170.4 exceedance probability level would be a major departure from previous earthquake loading standards, it would bring it into line with other international building codes in similar tectonic environments. Additionally, it would offer opportunities to further modernise how seismic demands are considered in Australian building design. In particular, the authors highlight the following additional opportunities: 1) the use of uniform hazard spectra to replace and simplify the spectral shape factors, which do not deliver uniform hazard across all natural periods; 2) updated site amplification factors to ensure continuity with modern ground-motion models, and; 3) the potential to define design ground motions in terms of uniform collapse risk rather than uniform hazard. Estimation of seismic hazard at any location is an uncertain science. However, as our knowledge improves, our estimates of the hazard will converge on the actual – but unknowable – (time independent) hazard. It is therefore prudent to regularly update the estimates of the seismic demands in our building codes using the best available evidence-based methods and models.

The use of Interferometric Synthetic Aperture Radar (InSAR) to monitor volcano hazards by detecting ground deformation has been demonstrated in numerous cases around the world. This report presents an investigation of the feasibility of using InSAR as a broad scale volcano-monitoring tool in Papua New Guinea (PNG). This type of ongoing broad-scale monitoring would be a significant leap forward compared to the majority of past applications of InSAR for volcano monitoring, which have been sporadic and often conducted in hindsight. A major focus of this study was the development of open-source InSAR analysis software which makes it easier to implement in developing countries where resources may be limited. The environmental conditions of PNG, such as steep topography, dense vegetation and the moist, turbulent atmosphere pose significant challenges to volcano monitoring using InSAR. On the other hand, the remoteness of many of the volcanoes and the limited geophysical resources currently employed to monitor them, makes a broad-scale InSAR monitoring system an attractive proposition. The viability of InSAR as an ongoing tool for broad-scale volcano monitoring in PNG is constrained by the future availability of L-band Synthetic Aperture Radar (SAR) satellite imagery. The ALOS-2 mission should meet the data requirements of a broad-scale volcano monitoring programme. However, the present cost of ALOS data is prohibitive to ongoing monitoring, given the large volume of data required. The planned ALOS-2 mission will acquire SAR data with even higher temporal resolution, but this will be of little use to InSAR monitoring unless it is available at a cost conducive to regular access. At present, the greatest single barrier to a broad-scale InSAR monitoring system is the prohibitive cost of obtaining the required SAR imagery. To improve the accessibility of InSAR processing software to those in developing countries, the InSAR processing workflow that has been developed in this study is open source, being based on the GMTSAR package. In addition the interface has been simplified and a greater level of automation has been implemented to reduce the training required to become operational. The system has been designed to deal with the large volume of data processing required in a broad-scale volcano monitoring operation by parallelizing the most computationally intensive parts of the workflow. A case study of the Rabaul caldera demonstrates that L-band SAR interferometry can overcome many of the challenges of applying InSAR in PNG. However, continued development is required to enable time-series InSAR analysis. This would help to resolve the nonlinear nature of volcano deformation events and reduce the impact of spurious atmospheric delay signals. Commercial software is available to meet this requirement but the development of an open source alternative would be desirable to make the platform inclusive of developing countries.

Understanding risk is a key tenet of the National Disaster Resilience Strategy and inherent to this is the discoverability, accessibility and availability of risk information. Access to this information is critical for land use or infrastructure planning decisions. Not only if this information required prior to the decision is made, but at some future date when investment is required to mitigate any created or residual risk. The community affected by these decisions also require the risk information so they can understand the hazard and risk and make decisions accordingly. Here, we showcase a suite of risk information developed by Geoscience Australia that can support land use and infrastructure planning decisions. GA officially adopted the Creative Commons 4.0 licence in 2009, recognising the investment made by the Australian Government in its development and the value it can serve to a range of stakeholders in government, industry, academia and the public. We contrast this with the case-study of the National Flood Risk Information Project where procurement practices of flood hazard and risk data have failed in delivering on the requirement of improving the community’s understanding of flood hazard and risk. We show how these challenges can be overcome so that ultimately decisions (for example in land use and infrastructure planning) can be made to minimise risk to the Australian community.

Tsunamis are relatively rare in Australia and emergency managers rely on the sharing of information at national forums to assist them to manage the tsunami risk in their own jurisdiction. Emergency managers responsible for tsunami risk management across Australia recently identified the need for national consistency in tsunami hazard information and as a result, a project was initiated to develop national guidelines for tsunami hazard modelling. This presentation will outline the approach adopted to develop these guidelines, focusing on the collaboration of end-users and tsunami modelling practitioners. The guidelines were explicitly designed to facilitate appropriate standards of rigour and improved national consistency in tsunami hazard modelling, without dictating software choices or otherwise suppressing innovative practices (which will evolve over time in concert with improvements in tsunami science). The guidelines focused instead on providing guidance in designing a study suitable for the use-case being considered. Core issues included the treatment of uncertainties in tsunami generation, propagation and inundation modelling, and scenario return periods. Whilst the emergency managers proposed the development of these guidelines, the target audience included any agency would could commission tsunami hazard studies for a particular purpose (e.g. coastal infrastructure owners, insurance), as well as the tsunami modellers conducting such studies. The guidelines will also become a valuable resource for the tsunami modelling community. In many situations, tsunami modelling is conducted by coastal hazard modellers who may not have current understanding of Australia’s tsunami hazard.

The 2018 Probabilistic Tsunami Hazard Assessmetn (PTHA18) outputs are can be accessed following the README instructions here: https://github.com/GeoscienceAustralia/ptha/tree/master/ptha_access