The Queensland coast has had a period of relative cyclonic calm since the storms that brought the Brisbane floods of 1974, but is that about to change? Cyclone Ingrid, centred 330 kilometres off Cooktown has just intensified to category five. Perhaps the BOM is playing it down, or maybe journalists don’t think they have any business alarming the public but that puts it in the Cyclone Tracy league.
Cyclone Tracy, for those who’ve forgotten, flattened much of Darwin at Christmas 1974, as well as partially leveling the career of Gough Whitlam – his apparent reluctance to return from an overseas trip cemented the public’s impression of imperial disdain for ordinary Australians.
The BBC reports that Tracy had winds of up to 135 mph. The Northern Territory Library says that the anemometer ceased functioning at 217 km/h. That would make it category three or four (three has wind gusts up to 224 km/h, and four up to 279 km/h). Category five is reserved for cyclones with wind gusts of 280 km/h plus – somewhere around 25% stronger.
Of course Ingrid may never come ashore, or if she does, never come to town. But if she hit Cairns, for example, the damage would be enourmous. Before Tracy, Darwin had whole suburbs full of high-set fibro houses; after, these were reduced to forests of bare stumps. It wasn’t only cheap construction that was affected. I also saw blocks of brick veneer flats which had had the top storey blown off them. That was a category three/four. The guide on cyclones at http://clearlyexplained.com/ puts the destruction of a category five cyclone at älmost total”.
Much of Cairns has been built recently, so building standards will be higher than pre-Tracy, but that probably doesn’t help with a category five. And of course there are many older buildings, and a cyclonic storm surge to worry about.
In a recent Courier Mail article (can’t find the reference but it is at work so will add when I can) a Tsunami expert said that we had to be prepared for a Tsunami on the Queensland coast sometime or another. He also said that the storm activity on the Queensland coast had been relatively benign in recent times, and that dunes running parallel to the coast and boulders high up and back from the coast reflected earlier violent events. Let’s hope the good times aren’t about to end now. Queensland’s coastal settlement patterns aren’t designed to deal with Tsunamis, or category five cyclones.