Adelaide rocked by earth tremor

Originally posted by ozzieman
reply to post by tauristercus

 

Hi Tauristercus & Nukepaul, we are neighbours. Oz


[edit on 16/4/10 by ozzieman]

And a big hi to you and Nukepaul ... it's a small world indeed

This is interesting:

Experts warn a major earthquake could hit Australia's capital cities.

According to Seismologist Dr Kevin McCue of Central Queensland University in Rockhampton, the Australian continent is hit by a magnitude 6 earthquake every five to six years and currently, one is overdue, " so we're just waiting to see what will happen in Victoria ", and he thinks that it is just luck we haven't had an earthquakes under Melbourne and Sydney.

Earthquakes frequently occur close to plate boundaries, where the plates that make up the earth's crust push and slide against each other.

Despite sitting in the middle of a tectonic plate, scientists say Australia is subjected to the stresses and strains from movements at the edges of plate boundaries. "Compared to Canada, US, South Africa, central Africa and India, Australia is more active,"

US seismologist Professor Paul Somerville, deputy director of Risk Frontiers, based at Macquarie University in Sydney, says Australia is under "quite high tectonic stress". "As is the case in other stable regions, the earthquake activity appears to be generally higher around the margins (edges) of the continent than in its interior," he says. "Since Australia's population is more concentrated on its coasts than other stable regions, this by itself presents a higher hazard level."

Australians are "complacent" to the risks posed by earthquakes and that one could strike a major city, say earthquake experts.

The warning comes after two moderate-sized earthquakes recently struck the Gippsland town of Korumburra in southeast Victoria. 06/03/2009
Both were felt 120 kilometres away in the city of Melbourne.

The earthquakes registered magnitude 4.6 on the Richter scale, with another small earthquake felt in the area in January 2009.
Both struck 15 kilometres below ground and were associated with uplift of the Strzelecki Ranges.

Source: Australians 'complacent' to earthquakes ABC Science Friday, 27 March 2009


The big earthquake still building South East Australia


Epicentres of Australian earthquakes in the period 1859 to 1992 with magnitudes of ML4 or greater.(Illustration courtesy AGSO)
Two separate geological studies have concluded that an area from Adelaide to south-east Victoria is seismically active and the next
'big one' could endanger lives and infrastructure.


Contrary to the popular notion that Australia is an ancient continent that has for millions of years been geologically comatose, University of Melbourne geologists have uncovered evidence that parts of South-eastern Australia recently stirred from their geological slumber and are in an active mountain building phase. These mountains are being shaped by earthquakes, some reaching greater than 6 on the Richter scale.

"When these big quakes reoccur, they have the potential to cause catastrophic damage to cities such as Melbourne, Adelaide, and the La Trobe Valley area, which straddle some of these major faults lines," says Professor Mike Sandiford, who conducted one of the studies.

Possibly, the most dramatic indication of this geological stirring, which the studies estimate began suddenly about ten million years ago, can be found in the landscape of the Mount Lofty Ranges near Adelaide.

"Some faults around Adelaide have moved slabs of the continent up to 30 metres in the last one million years," says Sandiford.

"A typical earthquake of magnitude 6.0 might produce a displacement of about one metre. Thirty metres is equivalent to 30-50 big earthquakes in the last million years," he says.

Other areas of intense mountain building have been around Victoria's Otway Ranges, Mornington Peninsula and Strzeleckis. In some of these areas, similar uplift and erosion over the last 10 million years have thrust chunks of Australia upwards in the order of one kilometre.

Tectonic movements have pushed the Otways 250 metres higher in the last three million years, and The Selwyn fault, which runs from Mt Martha, on Victoria's Mornington Peninsula, east to the Dandenong Ranges has possibly produced six metres of uplift in the last 100,000 years.

"This is potentially six big earthquakes," says Sandiford.

"We are still trying to determine the slip rates along these fault lines, but our evidence so far suggests that we should expect, on any one of the major faults, a large earthquake every 10-20,000 years. The estimated return period of a quake greater than 6.0 in south-east Australia is about 30 years, but none have been recorded in the last 100 years," he says.

"Most earthquakes experienced by this region are less than three on the Richter scale and occur several times a year. It is unusually quiet at the moment with nothing over 1.5 for the last few months."

Source: home.iprimus.com.au...

If you scroll about 2/3rds of the way down their page there is also a very good map showing the faultlines, which I don't have the knowledge to paste here, sorry.

Heres that map..




Earthquake hazard map..greater then 0.10



Intraplate fault lines

Honestly i am not surprised.

As Benjamin Creme said earlier this year we are now in the year of the Tiger.

The year of big earth changes. The year of the earthquake and volcano.

Mother natures birth pangs so to speak.

Stand back wrapped in awe as the sleeping giant awakens.

First Melbourne and surrounding regions, then the NSW coast, then Adelaide, now Kalgoorlie in Western Australia.

a 5.0

Moderate earthquake rattles Western Australia Goldfields

* Earthquake hits Goldfields region
* Some reports of damaged buildings
* Earthquake large for Australia
* Pictures: Goldfields earthquake
* Google: China earthquake

ABOUT a dozen historic buildings and a school have been damaged by an earthquake in the city of Kalgoorlie-Boulder, in Western Australia's goldfields.

The earthquake hit the Goldfields around 8.20am, closing the Kalgoorlie Super Pit and damaging buildings, PerthNow reported. It measured 5.0 on the Richter scale and is the biggest earthquake to hit the region in half a century, Geoscience Australia says.

The quake occurred one to two kilometres southwest of the Kalgoorlie city centre, but most of the damage was felt in Boulder.

The Fire and Emergency Services Authority (FESA) said about a dozen buildings were damaged in Boulder, mainly on Burt, Moran and Piesse streets.

"A balcony has collapsed at the Golden Eagle Hotel on Lionel Street and there has been damage to the Rock Hotel on Burt Street," FESA said in a statement.

"There has been severe structural damage to Boulder Primary School including a ceiling collapse."

Students were moved to a safer part of the school and were collected by their parents, FESA said.

Firefighters were also called to a gas leak in Boulder.

Two people were treated in hospital for minor injuries at the Kalgoorlie Hospital.

A Geoscience Australia spokesman said the quake was the largest to hit the city, a mining centre 600km east of Perth. Previous earthquakes in the region have not exceeded 4.2 on the Richter scale.

"This is quite a large earthquake for Australia and a shallow, potentially damaging, earthquake," he said.

WA Premier Colin Barnett said the quake had caused some structural damage to schools in the region, which were closed for the day for safety checks.

Largest mine shut

Australia's largest mine, in the heart of Kalgoorlie, the Super Pit gold mine operated by the Barrick/Newmont joint venture called Kalgoorlie Consolidated Gold Mines, has been temporarily shut.

Australian Workers Union (AWU) national secretary Paul Howes said first reports suggested that all AWU members were safe.

"AWU officials report that all our people have, it seems, been safely evacuated," Mr Howes said in a statement.

"We're not sure how long the mines will need to be shut down while damage is assessed.

"Certainly, we know now that at the open cut mine there has been some significant rockfalls, and we expect similar problems in the underground mines.

"The union will want to work co-operatively with the mine companies and the WA government to ensure everything is completely safe before miners are asked to restart operations.

"This incident is a huge reminder of the inherent dangers in our industry."

Aftershocks, smaller than the main earthquake, are expected and could cause more damage to weakened structures, FESA said.

Residents in the city have been told to turn off electricity, gas and power and told not to use matches, cigarette lighters or naked flames because of potential gas leaks.

A number of roads in the town have been closed, and people have been told to beware of fallen powerlines and falling debris.

www.news.com.au...

And a big hi to ozzieman and Tauristercus also!

Hey check this out.

I just found this about the March '54 quake here. On our own government's website:

"There were many reports of lights in the sky before the event."

Very interesting...



[edit on 21/4/10 by NuclearPaul]

I was at work and didn't even notice it, didn't find out 'til the next day. *shrug*
Maybe we'll get lucky and Port Adelaide will slip into the ocean with the next one.. and the seizmic activity will upset the sharks and dolphins and give them all a frenzied taste for bogan.

and greetz to the fellow Adelaideans!