Updated assessment reveals higher earthquake risks in Australia

Geoscience Australia has published its first update to the National Seismic Hazard Assessment since 2018, identifying heightened risks of strong ground shaking in Darwin and parts of the eastern highlands extending into Victoria’s Latrobe Valley.

The assessment defines the level of earthquake ground shaking across the country that has a given chance of being exceeded within a specific timeframe, providing critical information for emergency managers, government agencies, and engineers to prepare for and respond to seismic events.

Senior Seismologist Dr Trevor Allen explained, “Consistent with previous assessments, most areas around Australia are at low to moderate risk of experiencing strong ground shaking. However, our understanding has changed for some regions, such as Darwin and the Victorian high country.”

Dr Allen emphasised that the revised assessment does not indicate an increase in earthquake frequency or intensity. “What has changed is how we understand and interpret the risk of earthquakes occurring and their consequent ground motions,” he clarified.

Darwin’s elevated seismic risk is linked to its proximity to the Banda Sea, where earthquakes produce shaking energy that travels more efficiently to Northern Australia than to other areas, even those closer to the epicentre.

In Victoria’s high country, data from recent seismic activity has contributed to a slight increase in the region’s seismic hazard. Dr Allen said. “Each earthquake is unique and provides us with more information that can be used to understand the likelihood and physical consequences of earthquakes in Australia.”

Although Australia’s seismic hazard profile is lower than that of nearby nations such as New Zealand and Indonesia, many older masonry buildings remain vulnerable to earthquake damage. To help mitigate this risk, Geoscience Australia has released resources offering guidance on retrofitting unreinforced masonry buildings to better resist earthquake impacts.

The updated National Seismic Hazard Assessment is publicly available on the Geoscience Australia website.