Deniliquin Pastoral Times

Quake shock

- By JOHN THOMPSON

Felt from Newcastle to Adelaide — and everywhere in between — Wednesday’s 5.8 magnitude earthquake was the largest in Victoria’s recorded history.

Occurring at 9.15am the tremor was felt across Deniliquin and surrounds, shaking buildings and the people in them.

The magnitude of the tremor that hit Deniliquin has not been formally measured by Geoscience Australia.

Despite its intensity, there are currently no reports of structural damage or injuries in the local area.

The quake was followed by a magnitude 4.0 aftershock shortly after, which paled in comparison to the initial event.

The epicentre originated in the mountains of Mansfield, Victoria, fortunatel­y far from the nearest townships of Woods Point and Licola North, which contain relatively little infrastruc­ture and sparse population­s.

However, the same cannot be said of Melbourne, with residents reporting multiple instances of structural damage following the event.

Betty’s Burgers on Chapel St became arguably the most notable example, with footage of its collapse shared widely on both social media, and major news networks.

Working less than 2km from the damaged restaurant at the time was former Deniliquin resident Maddie Munro, at Dilly Dally Deli in Daly St.

‘‘The floor absolutely shook. We are in a small tin like garage with cement flooring.

‘‘Both my co-worker and I were like ‘what the hell is that?’, and next minute we have a shop full of people being evacuated from the building opposite us.

‘‘Our system was down so I had to hand write orders while still in shock and with a shop full of people.

‘‘We made $400 in 30 to 45 minutes, because of how busy it was.’’

Melbourne-based Seismology Research Centre’s chief scientist Adam Pascale said the centre’s nearest seismic monitoring station — roughly 50km from the epicentre — went ‘‘off the scale’’ when the quake hit.

He told the DENILIQUIN PASTORAL TIMES that many of the affected buildings were built using outdated constructi­on methods, which weren’t designed to mitigate earthquake­s.

‘‘What we saw was unreinforc­ed masonry — unsecured brick walls and the like — coming down. This is because of the style of constructi­on done before earthquake’s were a considerat­ion,’’ he said.

‘‘It’s another reason we advise people not to run onto the street during an earthquake. People tend to be injured or killed by falling objects during this kind of event. Instead we advise people to ‘Drop, Cover and Hold’.’’

Drop, Cover and Hold is the earthquake equivalent of the more widely known ‘Stop, Drop and Roll’ and it’s unsurprisi­ng many Australian­s aren't familiar with the advice.

‘‘We don’t have earthquake­s nearly as often as other countries because our entire continent rests atop one tectonic plate,’’ explained Mr Pascale.

‘‘We can’t really have big earthquake­s in this country, only up to a magnitude 7.5.’’

Scientists say Wednesday’s tremor was caused by pressure within Australia’s tectonic plate, which was created by the movement of surroundin­g plates.

And the reason it was felt so widely, according to Mr Pascale, is the same reason they are so rare.

‘‘The reason such a relatively small earthquake was felt so far away is because we have old, hard crust that’s cooled down over millennia.”

He explained that because our region has relatively little elasticity compared to more quake-prone countries, its aftershock­s travelled further than they typically would have.

Aftershock­s are expected to occur during the coming days, or even weeks, but are unlikely to match the intensity of Wednesday’s, with only ‘‘a couple’’ reaching magnitude two or three since the initial shock.

However, the aftershock­s could offer an insight into the seismic activity below Mansfield, including the cause of the event.

‘‘We’re planning on getting teams up there within the next few days to record seismic activity, this will basically give us a view of what’s happening below the surface in higher resolution 3D space,” said Mr Pascale.

The teams will use specialist equipment to effectivel­y map the surface below, and track where the aftershock­s are occurring along the fault.

In the wake of the tremor, multiple government agencies began routine inspection­s of their facilities, including hospitals.

While the quake did prompt investigat­ions into the integrity of the Hume Dam — which is currently at capacity, with releases causing water inundation at Deniliquin and other areas — WaterNSW told the PASTORAL TIMES ‘‘there are no immediate concerns’’.

‘‘In line with establishe­d procedures, WaterNSW is undertakin­g precaution­ary inspection­s on a number of its New South Wales dams, following reports of earth tremors in Victoria this morning,’’ the organisati­on said Wednesday.

‘‘Specialist WaterNSW personnel, including on-site teams, are verifying the condition of dam storages, including Hume, Blowering, Burrinjuck and Brogo dams along with Lake Cargelligo.’’

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