We present the first paleoseismic investigation of the Hyde Fault, one of a series of north-east striking reverse faults within the Otago range and basin province in southern New Zealand. Surface traces of the fault and associated geomorphology were mapped using a lidar digital elevation model and field investigations. Trenches were excavated at two sites across fault scarps on alluvial fan surfaces. The trenches revealed stratigraphic evidence for four surface-rupturing earthquakes. Optically stimulated luminescence dating constrains the timing of these events to around 47.2 ka (37.5–56.7 ka at 95% confidence), 34.6 ka (24.7–46.4 ka),23.5 ka (19.7–27.3 ka) and 10.5 ka (7.9–13.1 ka). We obtain a mean inter-event time of12.4 kyr (2.3–23.9 kyr at 95% confidence) and the slip rate is estimated to be 0.22 mm/yr (0.15–0.3 mm/yr). We do not find evidence to suggest that earthquake recurrence on the Hyde Fault is episodic, in contrast to other well-studied faults within Otago, suggesting diverse recurrence styles may co-exist in the same fault system. This poses challenges for characterising the seismic hazard potential of faults in the region, particularly when paleoearthquake records are limited to the most recent few events. <b>Citation:</b> Jonathan D. Griffin, Mark W. Stirling, David J.A. Barrell, Ella J. van den Berg, Erin K. Todd, Ross Nicolls & Ningsheng Wang (2022) Paleoseismology of the Hyde Fault, Otago, New Zealand, <i>New Zealand Journal of Geology and Geophysics</i>, 65:4, 613-637, DOI: 10.1080/00288306.2021.1995007

<div>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 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 shows at least three earthquakes on the Jindabyne Thrust, with the most recent event occurring within the Holocene, and also demonstrate late Pleistocene activity of the Hill Top Fault. The new insights into earthquake activity rates have implications for our understanding of seismic hazard and risk in the Snowy Monaro region, and elsewhere in the southeast highlands of Australia. Presented at the 2024 PATA Days (Paleoseismology, Active Tectonics, and Archaeoseismology) workshop, Chile