Swimmers were advised to stay away from this part of North Stradbroke Island after its collapse. (Photo: SLSQ/Twitter)
For the second time in three months, an Australian beach experienced a massive collapse, this one off the coast of Queensland leaving a hole measuring about 330 feet long by 330 feet wide.
The latest collapse is believed to have happened on Wednesday on an unpopulated section of North Stradbroke Island – the island is popular with tourists and fishermen. Surf Life Saving Queensland tweeted a photo of the hole and urged everyone to stay away because of the unpredictable and unstable nature of the currents.
Although SLSQ’s tweet initially called it a sinkhole, that’s probably not what this is. Stephen Fityus, a professor of geotechnical engineering at the University of Newcastle, told Mashable Australia this was likely a landslide caused by erosion.
Fityus said the same of a beach collapse in September at Inskip Point near Fraser Island in Queensland, which was found to have swallowed up a car and a camping trailer. At the time he wrote: “Unanticipated ground collapses occur around the world from time to time, and these generally get labelled ‘sinkholes,’ for want a more appropriate term.”
The professor told Mashable that erosion collapses like this are a natural part of how a beach repairs itself, and that people just need to be cautious of them.
“As with Inskip beach, I suspect that it’s in a location where there are longshore currents which variously deposit and erode sand on the submerged sand slopes beyond the beach,” he said. “Under the right conditions, if there is too much erosion at the toe of the slope, it becomes over-steep and loses stability, collapsing progressively back up to the surface.”
The Telegraph reported the lost sand already appeared to be returning to the beach with the tides.
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