In 2017 Queensland Fire and Emergency Services (QFES) completed the State Natural Hazard Risk Assessment which evaluated the risks presented by seven in-scope natural hazards. The risks presented by earthquakes were evaluated as part of this assessment in broad terms. The assessment highlighted a number of key vulnerabilities and risks presented by earthquakes to the communities of Queensland requiring further analysis. As QFES matures the Queensland Emergency Risk Management Framework (QERMF) by working with Local and District Disaster Management Groups (LDMGs/DDMGs), opportunities have arisen whereby QFES, in collaboration with relevant Federal and State Government and industry partners, are in a position to provide State-level support to LDMGs and DDMGs, through the development of in-depth risk assessments. The State Natural Hazard Risk Assessment 2017 and the State Disaster Management Plan 2018 note that the QERMF, as the endorsed methodology for the assessment of disaster related risk, is intended to: • Provide consistent guidance in understanding disaster risk that acts as a conduit for publicly available risk information. This approach assists in establishing and implementing a framework for collaboration and sharing of information in disaster risk management, including risk informed disaster risk reduction strategies and plans. • Encourage holistic risk assessments that provide an understanding of the many different dimensions of disaster risk (hazards, exposures, vulnerabilities, capability and capacities). The assessments include diverse types of direct and indirect impacts of disaster, such as physical, social, economic, environmental and institutional. The assessment and its intended audience This risk assessment was developed using the QERMF to undertake a scenario-based analysis of Queensland’s earthquake risk. It is intended to complement and support LDMGs and DDMGs in the completion of their risk-based disaster management plans. The development of the State Earthquake Risk Assessment 2018 was supported by Geoscience Australia (GA) through the provision of expert advice, relevant spatial datasets and the development of the scenarios used through this assessment. Input has been sought from GA to help contextualise the findings of the National Seismic Hazard Assessment 2018 for Queensland. Consultation with the University of Queensland has been sought to provide the ‘Queensland Context’, capitalising on the 80-year history of earthquake research and study undertaken by the university. A robust scientific basis enhances the assessment and enables disaster management groups to inform their local level planning. Overall, the assessment and associated report seeks to complement and build upon existing Local and District earthquake risk assessments by providing updated and validated information relating to the changes in understanding Queensland’s earthquake potential.

Coseismically displaced rock fragments (chips) in the near-field (less than 5 km) of the 2016 moment magnitude (MW) 6.1 Petermann earthquake (Australia) preserve directionality of strong ground motions. Displacement data from 1437 chips collected over an area of 100 km2 along and across the Petermann surface rupture is interpreted to record combinations of co-seismic directed permanent ground displacements associated with elastic rebound (fling) and transient ground shaking, with intensities of motion increasing with proximity to the surface rupture. The observations provide a proxy test for available models for directionality of near-field reverse fault strong ground motions in the absence of instrumental data. This study provides a dense proxy record of strong ground motions at less than 5 km distance from a surface rupturing reverse earthquake, and may help test models of near-field dynamic and static pulse-like strong ground motion for dip-slip earthquakes.

Damaging earthquakes in Australia and other regions characterised by low seismicity are considered low probability but high consequence events. Uncertainties in modelling earthquake occurrence rates and ground motions for damaging earthquakes in these regions pose unique challenges to forecasting seismic hazard, including the use of this information as a reliable benchmark to improve seismic safety within our communities. Key challenges for assessing seismic hazards in these regions are explored, including: the completeness and continuity of earthquake catalogues; the identification and characterisation of neotectonic faults; the difficulties in characterising earthquake ground motions; the uncertainties in earthquake source modelling, and the use of modern earthquake hazard information to support the development of future building provisions. Geoscience Australia 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 have challenged notions of seismic hazard in Australia in terms of the recurrence of damaging ground motions. Consequently, this raises the question of whether current practices in probabilistic seismic hazard analysis (PSHA) deliver the outcomes required to protect communities and infrastructure assets in low-seismicity regions, such as Australia. This manuscript explores a range of measures that could be undertaken to update and modernise the Australian earthquake loading standard, in light of these modern seismic hazard estimates, including the use of alternate ground-motion exceedance probabilities for assigning seismic demands for ordinary-use structures. The estimation of seismic hazard at any location is an uncertain science, particularly in low-seismicity regions. However, as our knowledge of the physical characteristics of earthquakes improve, our estimates of the hazard will converge more closely to the actual – but unknowable – (time independent) hazard. Understanding the uncertainties in the estimation of seismic hazard is also of key importance, and new software and approaches allow hazard modellers to better understand and quantify this uncertainty. 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.

This poster presents a summary of discussion topics following the 2018 Lake Muir, WA, Earthquake Sequence Community Engagement Workshop held in Frankland River, WA, on 28 November 2018

Damaging earthquakes in Australia and other regions characterised by low seismicity are considered low probability but high consequence events. Uncertainties in modelling earthquake occurrence rates and ground motions for damaging earthquakes in these regions imposes unique challenges on forecasting seismic hazard and the use of this information for improving seismic safety within our communities. Key challenges for these regions are explored, including: the quality and continuity of earthquake catalogues; the difficulties in characterising earthquake ground motions; the uncertainties in earthquake source modelling, and; the consideration of modern earthquake hazard information to support future building provisions.

This document reports on a Bushfire and Natural Hazards Collaborative Research Centre (BNHCRC) utilisation project that has sought to develop information on the most effective means to address York’s high risk buildings. It has also sought to develop a better understanding of the logistics that would be faced by the state emergency services and the local shire council in a rare but credible earthquake. The utilisation project is entitled “Earthquake Mitigation of WA Regional Towns: York Case Study”, and sits under the over-arching BNHCRC Project A9 “Cost-effective Mitigation Strategy Development for Building Related Earthquake Risk”. The work commenced in January 2018 and was undertaken over a two year period. It involved the University of Adelaide and Geoscience Australia as the CRC research partners, and DFES and the Shire of York as the end users. The WA DPLH has also been a participant, though not a formal BNHCRC end user. The project had the following key components:- • Develop a building, business and demographic exposure database for York with the attributes collected tailored for modelling earthquake impact and for quantifying avoided consequences in economic terms. • Examine the benefits and costs of retrofitting old URM buildings to improve the resilience of them to earthquake. This is to range in scale from individual households and businesses up to the community as a whole. • Prepare earthquake impact scenarios suitable for emergency management planning by DFES and the Shire of York.

We present earthquake ground motions based upon a paleoseismically-validated characteristic earthquake scenario for the ~ 48 km-long Avonmore scarp, which overlies the Meadow Valley Fault, east of Bendigo, Victoria. The results from the moment magnitude MW 7.1 scenario earthquake indicate that ground motions are sufficient to be of concern to nearby mining and water infrastructure. Specifically, the estimated median peak ground acceleration (PGA) exceeds 0.5 g to more than ~ 10 km from the source fault, and a 0.09 g PGA liquefaction threshold is exceeded out to approximately 50-70 kilometres. Liquefaction of susceptible materials, such as mine tailings, may occur to much greater distances. Our study underscores the importance of identifying and characterising potentially active faults in proximity to high failure-consequence dams, including mine tailings dams, particularly in light of the requirement to manage tailing dams for a prolonged period after mine closure. Paper presented at Australian National Committee on Large Dams (ANCOLD) conference 2020, online. (https://leishman.eventsair.com/ancold-2020-online/)

Segmented time series data for earthquake events. Data are in raw digital counts and have associated instrument metadata for calibration to physical ground-motion measures. These data are used to inform a range of applications in seismic hazard assessment and for assessing the utility of current observatory practice for magnitude assessment. <b>Value: </b>Used in the selection and development of ground-motion models used for seismic hazard purposes. These data also enable the assessment and development of new earthquake magnitude formulae. <b>Scope: </b>Data has been collected on an ad hoc basis, some early digital data dates back to 1989 (i.e. Newcastle earthquake), and the dataset continues to grow as earthquakes of interest occur, or various temporary deployments are rolled out. Instrument metadata is not always known.

Geoscience Australia and the NSW Department of Industry undertook seismic monitoring of the NSW CSG extraction area in Camden as well as baseline monitoring in the region between 2015 and 2019. Geoscience Australia established and maintained seismic stations to identify of events of greater than ML2.0 within the CSG fields. Three new seismic stations were located near Camden CSG area with two baseline stations in North-West Sydney. This poster details the station builds and seismic monitoring of both the Camden CSG production area and the wider region during the project.

Geoscience Australia provides 24/7 monitoring of seismic activity within Australia and the surrounding region through the National Earthquake Alerts Centre (NEAC). Recent enhancements to the earthquakes@GA web portal now allow users to view felt reports, submitted online – together with reports from other nearby respondents – using the new interactive mapping feature. Using an updated questionnaire based on the US Geological Survey’s Did You Feel It? System, Geoscience Australia now calculate Community Internet Intensities (CIIs) to support near-real-time situational awareness applications. Part of the duty seismologists’ situational awareness and decision support toolkit will be the production of real-time “ShakeMaps.” ShakeMap is a system that provides near-real-time maps of shaking intensity following significant earthquakes. The software ingests online intensity observations and spatially distributed instrumental ground-motions in near-real-time. These data are then interpolated with theoretical predictions to provide a grid of ground shaking for different intensity measure types. Combining these predictions with CIIs provides a powerful tool for rapidly evaluating the likely impact of an earthquake. This paper describes the application of the new felt reporting system and explores its utility for near-real-time ShakeMaps and the provision of situational awareness for significant Australian earthquakes.