Sinkhole at Rainbow Beach

Very spectacular Allan

Cheers

John

that looks like a great place to fish, looks deep and must have put a heap of food into the water

An instant deep water harbour for the ferry to Fraser.

Looks like a Shark bite on a surf board.

This is not a 'Happy Camper'!

I'll wager a number of people are thumbing through insurance PDS's this morning to see if sinkholes are excluded from their insurance policies, as "an Act of God"!!

The coastal plain to the north of Perth WA is mainly limestone and sandstone (surprise surprise). There is a river that flows during very heavy local rainfall in the Jurien Cervantes area, called the Nambung River, that flows towards the coast and if blocked by sand drifts from entering directly into the sea enters subterrainean caverns and reportedly can cause an area not far out from the shore line to be fresh enough to drink where it comes to the sea surface at some reef structure.
That whole area is riddled with caves and occassionally a depression forms on the land surface and now and then a sinkhole.
A ranger that patrolled the Nambung national park many years ago wrote in a book about one of the early settlers that while attempting to dredge a water hole deeper with a horse drawn dredge of some sort caused the floor of the waterhole to collapse into an underground cave. Apparently the farmer managed to scramble to safety but the horse and dredge dissapeared into the cavern and were never seen again.

Cheers
Pop