A 5.8 magnitude earthquake rocked parts of North Queensland, including Whitsundays holiday hot spot Hamilton Island.
The quake, which struck offshore near Bowen shortly after 2.30pm, was reportedly felt across Queensland at locations as far apart as Mission Beach, Shoalwater Bay, Charters Towers and Emerald.
It was followed by a smaller aftershock and experts say there could be plenty more to come.
Geoscience Australia siesmologist Hugh Glanville said the quake was unusually large for Australia. He called it the “biggest earthquake in Queensland in 20 years”.
“On average we get one or two earthquakes over magnitude 5 each year. We had a magnitude 6 in central Australia earlier this year but this is the biggest in Queensland in 20 years. It’s significant.”
Mr Glanville said it was highly likely Queenslanders would experience aftershocks.
“It’s definitely very likely. It’s say 99 per cent that it will happen. There’s a chance of a larger one but most likely there will be a series of smaller aftershocks.”
He said the quake lasted for at least 30 seconds, proving its size.
“Generally speaking we know the bigger the earthquake, the longer it lasts. It’s diagnostic in that sense, we know it was big based on how long it lasted.”
Airports including Cairns and Mackay evacuated as a precaution and flights were being diverted to other locations.
Airservices Australia, which controls air traffic at major airports, confirmed checks were undertaken on control towers to establish if any structural damage had occurred.
The airports were reopened shortly after 4.15pm local time.
— BOM Australia (@BOM_au) August 18, 2016