A sinkhole on North Stradbroke Island in Queensland noticed on Nov 25 that had stumped beachgoers is now starting to reappear. The site of the Stradbroke Island sinkhole next to Jumpinpin channel is being naturally refilled with sand deposited by the tide, according to the Queensland Parks and Wildlife Service (QPWS). However, swimmers are still being cautioned to stay clear of the area – initially described as “a sinkhole the size of a football field.”

Mick Cubis, southeast regional director of QPWS said that the site of the North Stradbroke Island “sand slump” had been inspected by rangers on Nov 26. “It's an area where the sand is constantly shifting, and sand is already returning with the tide,” said Cubis, according to Brisbane Times. “Queensland's coastal sand masses are dynamic environments and change all the time due to wind, tides and waves,” he clarified.

A “flow slide,” which is a kind of rapid beach erosion, had swallowed up a section of North Stradbroke Island, nearly 100 metres across. Surf Life Saving Queensland was notified of the sinkhole near the Jumpinpin channel – a stretch of the beach on the southern end of North Stradbroke Island, on the afternoon of Nov 25. It is believed that the occurrence of the sinkhole happened at a time when no one was around. A spokesperson for Surf Life Saving Queensland had cautioned people about the instability of the area around the collapse and warned them to stay away as more sand could break off.

Konrad Beinssen, coastal erosion researcher at the University of Queensland, clarified that the Stradbroke Island sinkhole was in fact a flow slide that could have likely been triggered by the sand at Jumpinpin channel flowing away and creating a sand cliff underwater. “These are things that get triggered offshore in underwater channels, these things can be triggered and they will move upslope and sometimes they peter out and sometimes they move up to the beach,” said Beinssen. “If you get fine tightly packed sand on a submarine slope, which is vulnerable to collapse, all you need is a trigger and just like a bushfire, it will grow and grow and grow,” he explained.

Source: YouTube.com/Andre Heath

Contact the writer at feedback@ibtimes.com.au, or let us know what you think below

RELATED STORIES