Farmer recently here in SE SA had a fright while driving tractor and boom spraying his ground....earth opened up around him, but safely escaped with some "white hair & soiled jocks".
This area has numerous cavities below our feet, so has me thinking as to how the extraction of billions cubic meters crude oil, extracting mineral wealth, and siphoning the worlds aquifer of water etc must surely be leaving behind enormous voids.
Bit like digging a tunnel sandy beach, soon collapses. Scary thoughts.
That was so interesting in the wake of a sinkhole in Ipswich (Qld) just last week - the area is near the Bremner River, and used to be mined. Authorities are saying an old mine has caused this, they have been working on it, and the family will be able to move back to their home.
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jules "Love is good for the human being!!" (Ben, aged 10)