2024 – Large Earthquake Recurrence in the Snowy Monaro Region: New Findings to Inform Dam Safety

Jonathan Griffin, Dan Clark, Justine Kemp, Mark Stirling, Tamarah King, Olivia Kulesza, James La Greca, Ambica Sharma, Mark Quigley, Dee Ninis, Tim Pietsch, Bethany Eaton, Klaus Wilcken

The Snowy Monaro region hosts major infrastructure critical to Australia’s energy and water security. It also hosts a number of active faults capable of hosting large earthquakes that may impact this infrastructure. However, to date the hazard and consequent risk from these faults has been poorly characterised. This study presents the initial results of geological investigations to understand how often large earthquakes occur on these faults, and how big they may be, with a focus on the Jindabyne Thrust and the neighbouring Hill Top Fault. The investigation reveals at least three earthquakes on the Jindabyne Thrust, with the most recent event occurring within the Holocene, and also demonstrates late Pleistocene activity of the Hill Top Fault. The new insights into earthquake activity rates have implications for dam safety management, risk assessment, emergency management and design, both in the Snowy Monaro region and elsewhere in the southeast highlands of Australia.