Earthquake would’ve killed or seriously injured 1400 if it hit Melbourne

Hundreds of people would have been killed or seriously injured if last week’s Victorian earthquake had struck beneath Melbourne.

More than 1400 people would be killed or severely injured and $160bn worth of damage caused if an earthquake similar to the one that hit Victoria last week struck directly beneath Melbourne, expert modelling shows.

Damage to the city’s infrastructure, such as bridges, tunnels and power supply, would be big, with disruption likely to go on for months, according to a paper for the Bushfire and Natural Hazards Cooperative Research Centre.

Based on a 6.0 magnitude tremor, similar to the one centred near Mansfield last Wednesday, a Melbourne quake would be a “catastrophic disaster” on a scale not seen before in Australia.

A damaged building on Chapel Street in Prahran. Picture: NCA NewsWire/Andrew Henshaw

Bushfire and Natural Hazards CRC commissioned researchers from firm Risk Frontiers to do the modelling for the paper Earthquake Scenario Melbourne.

Risk Frontiers general manager Andrew Gissing said while it might be a one-in-a-thousand-year event, Melburnians should be aware of the potential threat.

“There would be significant loss of life, significant property damage and also significant financial damage across Melbourne,” he said. “There would also be significant damage to essential services like power, water, gas and telecommunications.”

Debris strewn acros a road in Wattle Street, Prahran. Picture: Mark Stewart

The modelling estimates the city would suffer 1438 deaths and serious injuries, and $160bn damage to buildings and other infrastructure.

Mr Gissing said New Zealand’s 2011 Christchurch earthquake, which killed 185 and severely injured nearly 7000 people, showed what could happen to Melbourne.

“In Christchurch, you had awnings collapsing on people, rubble falling on people, and causing deaths and injuries,” he said. “We were really lucky last week we were in lockdown, because there weren’t a lot of people walking around populated places like Chapel St.”

Stunned residents beside a damaged building on Chappel St. Picture: AFP

Mr Gissing said Australia was lucky it wasn’t on a tectonic plate boundary, but there was still potential for intra-plate quakes, as last week’s tremor showed.

“If the earthquake had been a little bit bigger and centred directly underneath Melbourne, and it was relatively shallow, our work shows it would be very devastating,” he said.

“You’re going to have damage to bridges and tunnels, and that’s not just on the day. Things have to be repaired.

“You could have infrastructure disruption following an event like this for several months.”

Mr Gissing said that while a building code including earthquake risk covered commercial buildings, many “older-style masonry homes would be particularly at risk during an earthquake”.