Geoscience Australia (GA) has embarked on a project to update the seismic hazard model for Australia through the National Seismic Hazard Assessment (NSHA18) project. The draft NSHA18 update yields many important advances on its predecessors, including: 1) calculation in a full probabilistic framework using the Global Earthquake Model’s OpenQuake-engine; 2) consistent expression of earthquake magni-tudes in terms of moment magnitude, MW; 3) inclusion of epistemic uncertainty through the use of alterna-tive source models; 4) inclusion of a national fault-source model based on the Australian Neotectonic Features database; 5) the use of modern ground-motion models; and 6) inclusion of epistemic uncertainty on seismic source models, ground-motion models and fault occurrence and earthquake clustering models. The draft NSHA18 seismic design ground motions are significantly lower than those in the current (1991-era) AS1170.4–2007 hazard map at the 1/500-year annual ground-motion exceedance probability (AEP) level. However, draft values at lower probabilities (i.e., 1/2475-year AEP) are entirely consistent, in terms of the percentage area of land mass exceeding different ground-motion thresholds, with other Stable Continental Regions (e.g., central & eastern United States). The large reduction in seismic hazard at the 1/500-year AEP level has led to engineering design professionals questioning whether the new draft design values will provide enough structural resilience to potential seismic loads from rare large earthquakes. This process underscores the challenges in developing national-scale probabilistic seismic hazard analyses (PSHAs) in slowly-deforming regions, where a 1/500-year AEP design level is likely to be much lower than the ANCOLD Maximum Credible Earthquake (MCE) ground motions. Consequently, a robust discussion among the Standards Australia code committee, hazard practitioners and end users is required to consider alternative hazard and/or risk objectives for future standards. Site-specific PSHAs undertaken for owners and operators of extreme and high consequence dams generally require hazard evaluations at lower probabilities than for typical structural design as recommended in AS1170.4. However, modern national assessments, such as the NSHA18, can provide a benchmark in terms of recommended seismicity models, fault-source models, ground-motion models, as well as hazard values, for low-probability site-specific analyses. With a new understanding of earthquake processes in Australia leading to lower ground-motion hazard values for higher probability events (e.g., 1/500-year AEP), we should also ask whether the currently recommended design probabilities provide an acceptable level of seismic resilience to critical facilities (such as dams) and regular structures. Abstract presented at the 2017 Australian National Committee on Large Dams (ANCOLD) Conference

The Evidence Based Decision Making (EBDM) paradigm encourages managers to base their decisions on the strongest available evidence, but it has been criticized for placing too much emphasis on the choice of study design method without considering the types of questions that are being addressed as well as other relevant factors such as how well a study is implemented. Here we review the objectives of Australia’s Marine Park network, and identify the types of questions and data analysis that would address these objectives. Critically, we consider how the design of a monitoring program influences our ability to adequately answer these questions, using the strength of evidence hierarchy from the EBDM paradigm to assess the adequacy of different design strategies and other sources of information. It is important for conservation managers to recognize that the types of questions monitoring programs are able to answer depends on how they are designed and how the collected data are analyzed. The socio-political process that dictates where protected areas are placed typically excludes the strongest types of evidence, Random Controlled Trials (RCTs), for certain questions. Evidence bases that are stronger than ones commonly employed to date, however, could be used to provide a causal inference, including for those questions where RCTs are excluded, but only if appropriate designs such as cohort or case-control studies are used, and supported where relevant by appropriate sample frames. Randomized, spatially balanced sampling, together with careful selection of control sites, and more extensive use of propensity scores and structured elicitation of expert judgment, are also practical ways to improve the evidence base for answering the questions that underlie marine park objectives and motivate long-term monitoring programs. <b>Citation:</b> Hayes KR, Hosack GR, Lawrence E, Hedge P, Barrett NS, Przeslawski R, Caley MJ and Foster SD (2019) Designing Monitoring Programs for Marine Protected Areas Within an Evidence Based Decision Making Paradigm.<i> Front. Mar. Sci</i>. 6:746. doi: 10.3389/fmars.2019.00746

Papua New Guinea (PNG) sits at complex boundary between three major tectonic plates and eight microplates. As a result of this setting, the region experiences significant seismic activity that gives the country a hazard that ranges from low in the south west of the country up to very high by global hazard levels found at plate boundaries. This hazard has been long recognised and the suite of building standards released in 1982 contain provisions to impart resilience to buildings that were based on the best understanding of seismic hazard available at that time. The associated design methodologies in the standards also embody design methodologies that reflect the then current seismic design practice including requirements for achieving structural ductility in design using a range of structural materials. With a bedrock hazard that varies across the country, the overall objective of the suite of standards is that the design provisions impart properly constructed buildings with a strength and toughness compatible with the local hazard severity.

Earthquake design standards seek to ensure that structures are adequately resilient to local hazard. The probabilistic hazard that forms the basis of the design loadings used and the methods by which they are calculated typically reflect the best available information and practices at the time. This was the case with the earthquake loadings standard for the design of PNG buildings that was published in 1982. However, with the collaborative development of a better understanding of earthquake hazard across PNG the need to adjust the earthquake loadings for design through an Interim Amendment was highlighted. This key step would precede any more general and broader update of national building regulations. In this paper the process taken to translate the latest earthquake hazard assessment for PNG, PSHA19, to design practice is described. This included an assessment of the level of current under-design and the engagement with stakeholders in PNG to assess their needs through workshop activity. The central document to this process, “The Interim Amendment to PNGS 1001-1982: Part 4: Earthquake Design Actions”, is described and goes beyond the incorporation of the new design hazard to the introduction of new approaches for assessing earthquake loads that more closely align with those used in New Zealand and Australia. Preparation and delivery of seminars in-country to familiarise design professionals with its use are also described along with the series of professional development video products also developed for use in PNG. Finally, future needs in regulatory development in PNG are outlined. Presented at the 2023 Australian Earthquake Engineering Society (AEES) National Conference