QUEENSLANDERS 900km apart experienced the state’s biggest earthquake in 20 years on Thursday afternoon.

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.”

Mag 5.8 Offshore Bowen, QLD. 18 Aug 2016, 14:30(AEST). Lat/Long -19.85 148.66 Depth 0km Info is prelim. #eqaus — EarthquakesGA (@EarthquakesGA) August 18, 2016

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.

Marcus Johnson was on the ninth floor of his hotel on Hamilton Island when he felt the building shake and heard screaming.

Mr Johnson told news.com.au the earthquake “gave the cleaners a fright”.

“Some screamed,” he said. “Some people went to the ground ... (There) was a second tremor a few minutes later.”

He said the hotel informed visitors the earthquake was minor and that the building had been given the all clear. Social media lit up immediately with reports from others experiencing the ground shaking.

On holidays on @HamiltonIsland grabbed kids ran outside as everything as an earthquake just hit. — brigid glanville (@brigidglanville) August 18, 2016

Wow just felt my first earthquake in townsville of all places, said to be 5.8 magnitude off the coast of Bowen 😳 — Justin O'Neill (@Juz_e) August 18, 2016

Staff in the Townsville CBD were temporarily evacuated from their buildings as inspectors checked for damage.

An IGA store in Townsville shared CCTV footage of the quake on Facebook. In the video, several items can be seen falling from store shelves.

Richard Olearczyk was working in a government building in Carins when he felt the room start to shake.

“(There was) swaying felt by the staff, roller blind strings banging against the windown frames in unison. It was scary,” he said.

Heather Lewis, who works at a gift store nearby, told news.com.au she looked up “to see one of the card stands rocking back and forth.

“I thought, ‘Why is that rocking? There is no one in here’.”

The Bureau of Meteorology confirmed there is no tsunami threat and the Queensland Police Service said it had not received any reports of major damage.

Police have urged the public to avoid calling triple-0 unless the matter was urgent. They said they had received a large number of phone calls from residents in areas where the earthquake was felt.

Queensland experienced three Magnitude 5 earthquakes in 2015 and one in 2011.

Did you feel it? Email rohan.smith1@news.com.au or Twitter: @ro_smith