<p>Earthquake risk is not limited to tectonic plate boundary countries. While less frequent, significant earthquakes can occur in intraplate countries like Australia which can have severe consequences. For Australia this is particularly the case as earthquake hazard has not been recognised in the design of buildings and community infrastructure for most of the country’s settled history. Significant risks exist where community assets are by their nature inherently vulnerable to strong ground shaking. This paper describes three initiatives that are assisting Australian emergency management, infrastructure managers and local government to prepare for and mitigate these risks. <p>The first of these highlights how the characteristics of geological hazards differ from severe meteorological hazards. The very non-linear nature of impact severity with longer average recurrence interval earthquakes is demonstrated and how this information is supporting emergency management planning including capacity sharing between Association of Southeast Asian Nations (ASEAN) countries in the region is described. Secondly, the paper describes how this research is developing knowledge of the factors behind the vulnerability of critical infrastructure facilities and the options to mitigate these. The software tool System for Infrastructure Facility Resilience Analysis (SIFRA) is described which enables infrastructure facility components to be examined in the context of physical vulnerability, system criticality, repair cost and restoration time. Finally, a utilisation project of the Bushfire and Natural Hazards CRC working with the local government of York Shire in Western Australia (WA) is described. The project is providing information on the effectiveness of targeted retrofit of the heritage town of York to rare earthquakes and how this action by property owners can be incentivised.

<div>We performed an earthquake risk assessment of seven smaller communities across the Yilgarn of Western Australia (WA): Northam, Merredin, Cunderdin, Kellerberrin, Wundowie, Meckering, and Tammin. This was done as a part of activities of a project entitled “Risk Assessment and Mitigation Study for Earthquakes in the Yilgarn” which, in addition to assessing risk posed to buildings by earthquakes, has a focus on understanding critical infrastructure system risk in the Yilgarn region. We modelled earthquake hazard based on the 2018 National Seismic Hazard Assessment and Geoscience Australia’s seismic site conditions map for Australia. Building exposure data was compiled by a desktop survey using available aerial imagery, purpose captured GoPro streetview type imagery and publicly available real estate information to record building attributes. We used Geoscience Australia’s current vulnerability functions which include a range of models collaboratively developed for high-risk unreinforced masonry buildings. The estimated average annualised loss ratios for the communities range from 0.008% to 0.027%, with the highest being for Kellerberrin, and the lowest being for Wundowie. We combined the damage related risk with the Australian Disaster Resilience Index to identify communities of high risk and lower resilience. Six earthquake scenario events were modelled along with the risk and impact reductions achieved through a virtual retrofit of old URM buildings in the communities. In this paper the outcomes of this research are presented and discussed in a national context.&nbsp;</div> Presented at the 2023 Australian Earthquake Engineering Society (AEES) National Conference

<div>We performed an earthquake risk assessment of the state of Tasmania through a collaboration between the Tasmania Department of State Growth and Geoscience Australia with geotechnical and geological support from Mineral Resources Tasmania (MRT). We developed local surface earthquake hazard maps for Tasmania, focusing on the twenty largest communities, based on the 2018 National Seismic Hazard Assessment and seismic site conditions map for Australia augmented by geotechnical information provided by MRT. For the building exposure database, the National Exposure Information System was augmented with an engineering survey of Hobart central business district (CBD) undertaken by GA. We used GA’s current vulnerability functions including a range of models for high-risk unreinforced masonry buildings (URM). With a focus on the Hobart CBD, retrofit measures were applied to the URM building types in order to quantify the effectiveness of mitigation. This study provided a synoptic state-wide view that enabled the identification of communities of high risk and low resilience by combining the damage related risk with the Australian Disaster Resilience Index. In addition, three earthquake scenario events centred on Hobart were modelled along with the impact reduction achieved through a virtual retrofit of old URM buildings in the Hobart CBD.&nbsp;</div><div><br></div>This paper was presented to the 2022 Australian Earthquake Engineering Society (AEES) Conference 24-25 November (https://aees.org.au/aees-conference-2022/)