The areas of Australia most likely to suffer a serious earthquake were laid bare today in the first update to the National Seismic Hazard Assessment (NSHA) for six years.
Geoscience Australia says WA’s Wheatbelt region and Gippsland in Victoria are prone to the heaviest quakes in the country.
Its latest report provides information to government agencies and regulators, “so buildings and infrastructure design standards can be updated to mitigate the impact of strong earthquake ground shaking”.
“Although we cannot predict the exact day, time and place of a large, damaging earthquake, we can apply best practice and evidence-based science to make sure communities are as prepared as possible,” Senior Seismologist Trevor Allen said.
Residents in WA’s Wheatbelt, in the state’s southwest, can expect a magnitude 5 quake every 10-25 years. The area has historically experienced high rates of seismic activity, including the 1968 magnitude 6.5 quake near Meckering, which destroyed the town and damaged buildings in Perth, 130km away.
Gippsland’s Latrobe Valley and Strzelecki Ranges contain some of Australia’s most active faults “which have the potential to host a very large earthquake”.
A magnitude 5 quake is expected to hit the region every 25-50 years. The most recent was a magnitude 5.4 quake near the Latrobe Valley town of Moe in June 2012, which was followed by more than 200 aftershocks.
Among capital cities, Canberra has the highest seismic hazard because of its proximity to the Lake George and Murrumbidgee faults.
On average, 100 earthquakes of magnitude 3 or higher are detected across the country every year.
“There is always more to learn when it comes to earthquakes in Australia.” Dr Allen says.
“Science and technology is constantly evolving and improving and the NSHA is updated regularly to ensure it incorporates best practice and evidence-based science.
“In regions like the Wheatbelt and Gippsland, it is an essential tool for developing mitigation strategies that make at-risk communities more resilient.”
Dr Allen says earthquakes can also occur in “unanticipated” locations.