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Following the recent earthquakes that rocked Seddon and Wellington, experts have warned that Dunedin, or anywhere else in the South Island, could be next.

The most recent major earthquake in Dunedin occurred when the Akatore fault moved in 1974. However, the Akatore, along with two other active nearby faults, Titri and Maungatua, only “rupture once every 1,000 years,” according to Dr Andrew Gorman, an Otago Professor of Geophysics. This reduces Dunedin’s vulnerability significantly.

However, Dunedin’s nearest fault lines are not the primary concern. Rather, the Alpine Fault, which lies along nearly the entire length of the South Island’s west coast, has a pattern of large seismic movement every 200-300 years. The last significant shake was in 1717, meaning a large earthquake could, theoretically, strike at any time.

Gorman points out that “in Dunedin, you are as far away as you can get from the Alpine fault.” The possibility of the Alpine fault rupturing in the next 30 years is estimated at 35 per cent.

A strong earthquake in Dunedin could cause considerable damage to hillside properties and from liquefaction, but this damage would be minor in comparison to that experienced in Christchurch. Due to many Christchurch suburbs being built on old swamps and loose ground, the sediment was huge – “some of the worst in the world,” according to Gorman.

South Dunedin, despite being what some might call a “hole,” would unlikely be destroyed in the event of a large earthquake. “Even South Dunedin would be okay because the bedrock is not far below the surface,” Gorman explains, much to the relief of the wider Dunedin area.

The University has added steel plates to reinforce buildings that may not have held up during an earthquake. However, the Registry office is yet to be improved.

Despite the 1974 Akatore Earthquake occurring off the shore of St Clair, Gorman says that there is little chance of a tsunami occurring. “The shape of the coast is not conducive; it’s a flat coast and not a big risk.”

The location of the recent Seddon earthquakes was fortunate. Had the epicentre been located underneath Wellington, things could have been fatal. “A medium-sized earthquake in a big city would be a lot different,” Gorman warns.