Rainbow Beach tremor could be followed by after shocks
THE considerable earthquake off Fraser Island which rocked south-east Queensland yesterday morning has been described as a "once in a 100 year quake".
Queensland seismologist Mike Turnball, of the Central Queensland Seismology Research Group, said the magnitude 5.6 quake was very near the equivalent of 200 atomic bombs going off 10km under the ground.
"We've had a good earthquake," Mr Turnball said of the tremor that occurred 80km east of Fraser Island at 9.45am yesterday and was felt from the Gold Coast to Rockhampton and as far west as Gin Gin.
"If this type of thing happened on land, we'd be having ambulances racing around everywhere," he said, noting the Newcastle quake of 1989 with the same magnitude that killed 13 people.
While a large volume of water stifled its impact on the mainland, the event did not go unnoticed.
Social media went into overdrive as residents around the region told of their experiences.
Joe McLeod at Tin Can Bay reported strong shaking just after 9.45am that lasted for five or seven seconds.
"I've never felt anything like that in the house before," he said, telling how neighbours across the road came into the street to see the cause of the shaking.
This mornings earth tremor recorded in Clayton's Nambour Head Office, turn the sound up, watch the plants/computers. Whole building was swaying, sure had us all wondering what was going on for a minute there.Posted by Claytons Towing on Wednesday, 29 July 2015
Cr Julie Walker said it felt like an elephant running through her house.
Rainbow Beach resident Nev Holt said he was on the bottom level of his two-storey home signing papers with a builder when the building started to shake. He said his wife, who was upstairs, wondered out loud what "the pair were up to down there".
In Gympie, Brett Green said he was working at his desk in his Red Hill home when his house shook violently, causing a picture to fall from the wall and cups to rattle in the sink.
Staff on the higher levels of the Gympie hospital watched their computers shake and windows rattle so much and one staff member thought she was having a dizzy spell.
Mr Turnball said it was not an unusual occurrence for the Central Queensland region to get a quake of its magnitude.
He said the two hot spots in the region - north of Gayndah (between Monto and Mt Perry) and the area where yesterday's quake occurred - generate more earthquakes than anywhere else in Queensland.
Just as Mr Turnball recorded hundreds of aftershocks following Queensland's 5.2 magnitude quake near Eidsvold in February, he expects to do the same after yesterday's tremor.
"I would expect to see aftershocks for at least another six months, but the majority will not be felt by anyone," he said.
He said it was his forecast that a magnitude 6 quake will occur in the area in the next 100 years.
The BoM said there was no tsunami threat to the coast, and Mr Turnball said the magnitude would have to be closer to 7 for that to occur.
1883, Gayndah, 5.6 magnitude, major damage
1913, Charters Towers, 5.7 magnitude
1918, Lady Elliot Island, 6 magnitude, major damage
1935, Gayndah, 5.2 magnitude, one person dead
1954, St George, 5.3 magnitude
1974, The Coral Sea, 5.1 magnitude
1978, Heron Island, 5.2 magnitude
2011, Central Queensland 5.3 magnitude
Feb 2015, Eidsvold, 5.1 magnitude
Yesterday, 80km east of Fraser Island, 5.6 magnitude