© Bill Bradley / WikimediaCyclone Tracy, which hit Darwin, Australia, on Christmas Day 1974, killed 65 people and destroyed 70% of the city's homes, but is a "mere kitten" compared to a 'black swan' cyclone that could hit the city – and others – in the future.
San Francisco: There is a small but real chance, scientists say, that super cyclones with freak 10-metre storm surges could hit cities such as Darwin, Australia, Tampa, Florida and Dubai in the United Arab Emirates.
Such a storm is an example of what Ning Lin, a civil and environmental engineering professor at Princeton University in New Jersey, USA, calls a "black swan" cyclone. Something similar, she says, could hit the Persian Gulf, inundating unprepared cities like Dubai - which has never seen a cyclone - with similarly enormous storm surges.
"A black swan is a surprise with huge impact," she said yesterday at a meeting of the American Geophysical Union in San Francisco, California. "For this study, we defined [it] as an event which cannot reasonably be anticipated based on historical records alone."
Comment: Here's a video of the other sinkhole in Santa Cruz (more of a landslide really):