North Queensland regularly suffers under the onslaught of cyclonic winds and driving seas, but scientists don't think Australia's top end has seen how big and bad a cyclone can be.
Could cities such as Cairns withstand the ferocious attack of a 'super cyclone'? A geological dig through a 6,000-year history of cyclones in the region reveals that the worst is yet to come - and it's time to batten down the hatches.
Narration: North Queenslanders beware - a supercyclone, bigger than anything you've seen before, is coming your way. And Cairns may not be able to cope with a cyclone from hell.
Jonathan Nott: Generally Europeans haven't been in north Queensland since the last super cyclone but one is definitely going to occur in the future.
Narration: Cyclones are regular visitors to Cairns. Cyclone Steve hit in 2000 causing extensive damage. It was one of the strongest storms recorded in the area. But this is not the worst that can happen.
Steve was a pup. If a small cyclone can cause this much damage, imagine what a really big cyclone could do. Dr Jonathan Nott from James Cook University at Cairns has been looking into the geological record to figure out how often cyclones hit the North Queensland coast.
Today he's taking me to one of his study sites on Fitzroy Island, just off the coast from Cairns.
Jonathan Nott: Out there is the Great Barrier Reef so the beaches here are not made of sand, they're made of broken coral. This coral shingle is washed onto the beach during storms.
Narration: Cyclones create storm surges and these walls of water push the shingle into ridges at the back of the beach. The bigger the cyclone, the bigger the storm surge, the bigger the shingle ridge it leaves behind.
Jonathan Nott: We have a small ridge here that is deposited by a relatively moderate size cyclone. A ridge behind that what was deposited by an earlier cyclone that was bigger again and then back into the rainforest we have another deposit that was deposited by a very large or very intense cyclone.
Narration: By measuring shingle ridges Jon's been able to build up a 6,000 year history of cyclones in North Queensland. He's found dozens of super cyclones - enormous storms the likes of which have not been seen within historic times. The last big cyclone seen in Cairns hit in 1920. It had a storm surge of just 2.5 metres.
Jonathan Nott: In the early 1800's we had a storm surge which was more than 4 metres high and that would have been at least a metre over my head as I sit here now.
Narration: As you can see Cairns has changed quite a bit in the last 80 odd years. As the city has grown and developed, the building regulations have been tightened to account for the strongest cyclones on record. But, if Jon's right, they ain't seen nothing yet.
Cyclone Vance was Australia's biggest recorded cyclone. It hit the North Coast of Western Australia in 1999 with 267 km/h winds. Homes and buildings built to withstand cyclonic winds were no match for Vance. More than 240 were damaged, half beyond repair.
Destruction came from both the extreme winds and a ferocious sea. The storm surge was a 6 metre high wall of water. It ploughed up to a kilometre inland stripping bare everything in its' path. Is Cairns ready for a Super-cyclone? Built to withstand smaller cyclones, the 300kmh winds of a super-cyclone would leave half of Cairns uninhabitable. A storm surge greater than 4 metres would devastate the waterfront and shopping districts.
If the city is evacuated there should be no loss of life but the damage bill could run into many millions of dollars.
Jonathan Nott: These events occur every two to three hundred years and it has been a couple of hundred years since the last one hit this region here around Cairns. So we know that they're going to occur in the future. We don't know when they will occur, but we know that one will definitely occur in the relatively near future."
Narration: Jon's findings have only just been published in the journal Nature, so the authorities haven't really had time to take on board his warnings. It may well mean that building regulations have to be tightened even further and development close to sea level stopped altogether.
But the take home message is BEWARE: killer cyclones will hit north Queensland.