Researchers have warned that one of Australia’s largest cities is at risk of an earthquake predicted to be 30 times more forceful than Christchurch’s 2011 disaster, which had a magnitude of 6.3 on the Richter scale, and killed 185 people.
Experts from Geoscience Australia, the University of Melbourne, and the Seismology Centre recently excavated two large trenches along the Willunga fault located just south of Adelaide, and uncovered evidence of huge quakes that predate local records. After studying layers of sediment displaced by past tremors to estimate the potential magnitude of future quakes, they found that there was a minor, but very real risk, of a “big one” hitting in the future.
According to Geologist Dr. Dan Clark, “We calculate the 55km active length of this fault could potentially host an earthquake as large as magnitude 7.2.”
An earthquake of this size would involve approximately 30 times the energy released by the earthquake that hit Christchurch.
The city of Adelaide straddles two major faults: the Parra fault and the Eden fault, making it one of the most seismically active areas in the country. In the past decade alone, 10 quakes exceeding 3.0 on the Richter scale have occurred within 150 km of the South Australian capital.
However, “big quakes clocking above 6.0 don’t often happen close to populated areas in Australia, thankfully,” according to Adam Pascale, Chief Scientist at the Seismology Research Centre.
Whilst our cities should be prepared for these events by improving critical infrastructure, facilities, and the community in general, Dr. Clark has urged people not to worry, noting that a massive quake “might occur once every few tens of thousands of years”.
The recent findings have been described as an “advance” from what was previously known about the vulnerability of Australians concerning future earthquakes.
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