A magnitude-5.8 earthquake originating in Mansfield, Victoria has been felt as far as Adelaide, Sydney and Launceston in Tasmania, causing damage to buildings in Melbourne.
Buildings in the Victorian capital have reportedly been evacuated after the earthquake, which was followed by three lower-magnitude earthquakes.
Geoscience Australia, the Australian Government agency that reports on significant earthquakes, reported the earthquake occurred 10km deep near Mansfield. For comparison, the 2011 Christchurch earthquake in New Zealand which killed 182 people was at a depth of 1 to 2km.
Most of the impact was felt in Melbourne and its surrounds on a light-to moderate scale. Deputy Premier James Merlino said buildings had been damaged in the Mansfield township, and as he gave a press conference there had been 46 reports of damages in the state, mostly minor and with no injuries.
Merlino noted reports of building damages in Kensington, Ascot Vale, Parkdale, Prahran, Balwyn, Elsternwick, Northgate and West Melbourne. The Beechworth Hospital lost power but has back-up, while an electricity outage temporarily affected 35,000 customers, mostly in northern metropolitan Melbourne.
"Geoscience have confirmed it is a possibility that we may receive further aftershocks and potential risk of further earthquakes; indeed, more aftershocks could occur for weeks," Merlino said.
In terms of historical events, a spokesperson for the Insurance Council of Australia (ICA) said a 5.6-magnitude earthquake that hit Newcastle, NSW in 1989 caused $3.2 billion in insurance losses. Meanwhile, a 5.4-Richter Scale event in Moe, southern Victoria in 2012 caused little damage.
"The Insurance Council of Australia is currently monitoring the number of damage claims being received by insurers resulting from the today’s earthquake and aftershock, we are working with the Victorian State Government to ensure assistance is forthcoming for impacted property owners," the spokesperson said.
"Victorians impacted by this morning’s earthquake should ensure their safety as the priority, when safe to do so check your property for damage, if you believe the property has sustained structural damage contact the SES for assistance.
"Call your insurer or insurance broker to lodge a claim as soon as possible. Under the current COVID-19 restrictions insurers are permitted to conduct assessments and arrange emergency make safes and urgent repairs."
Luke Gallagher, Insurance Australia Group's (ASX: IAG) executive general manager direct claims, says the group had so far received 100 claims for property damage across its brands, including RACV, CGU Insurance, WFI Insurance and Coles Insurance.
"The priority at the moment is people’s safety, and we urge everyone to follow the directions of the emergency authorities, as there could be aftershocks which could cause further damage," Gallagher said.
"Our dedicated Major Events team is in place all year round to ensure we are as well prepared as possible to support our customers following a natural disaster.
"We encourage our customers who have suffered damage to their homes or properties to contact us to lodge their claim so we can provide immediate support, such as emergency make safe repairs and temporary accommodation, as quickly as possible."
Geoscience Australia also reported the earthquake was felt in Adelaide, Sydney, Launceston and Canberra, though on a “weak” scale.
While reports are still coming in, social media posts show structural damage to buildings in Melbourne, including on Chapel Street.
Greater risk for buildings designed before 1979
Richard Salter, head of structural engineering in Victoria and South Australia for Arup, highlights design requirements that have been in place since the late 70's in Australia for structures of a certain risk category.
He tells Business News Australia that buildings designed and built before 1979 weren't specifically designed for seismic loadings "but that’s not to say they don’t have capacity to deal with them".
"When you’re talking about an earthquake, you want a building to absorb the energy of the earthquake, and for the building to have a certain level of what we call ductility," Salter says.
"Think about a paperclip bending back and forth - you can do that once or twice without it breaking, and that's because steels and metals have a level of ductility so they can absorb a shake and not collapse.
"You’re looking to absorb load through that ductile mechanism, and timber and steel for example are good at that. Concrete buildings, which are most common in Melbourne for buildings of scale, can be designed and are designed to be specifically able to absorb those dynamic loads from earthquakes."
However, the engineer explains older buildings with significant brickwork are more at risk.
"Where you certainly run into trouble, and we’ve seen it around the world and I think we’ve seen it today, is masonry construction that for want of a better term is effectively brittle," he says.
"If you shake a brick parapet that has no restraint from say a timber or a steel structure, then once that brick wall or parapet is overloaded or pushed off balance, it will collapse. It has no mechanism to right itself.
"Your well-detailed concrete and steel modern buildings shouldn’t be at risk, but certainly where you have buildings with significant brickwork that’s where we as engineers need to put a lot of focus on designing that appropriately to be restrained, and that’s where historic buildings can be at risk, and that’s where you see cracking."
No damage done to mine near earthquake epicentre
A mine operated by ASX-listed White Rock Minerals (ASX: WRM), located approximately 60km south from the epicentre of the Mansfield earthquake, was not damaged this morning, with all personnel safe and accounted for.
According to the mining company, the Woods Point Gold Project site experienced significant shaking and aftershocks were still being felt at the time the statement was published to the ASX.
Nine personnel were underground at the time, and all are safe, accounted for, and back on the surface.
"The shaft and winder remained operational and there are no immediate signs of damage," WRM said.
"Site management are following their Emergency Response protocols and have devised an inspection plan for site and underground infrastructure.
"At this stage there is no plan to immediately return to underground activities until the aftershocks have subsided, and only at such a time that the site integrity has been checked/inspected to confirm no damage."
Shares in WRM are up 1.82 per cent to $0.28 per share at 11.13am AEST.
More to come…
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