“Central Australia: World's biggest gravity warp
Driving along the Stuart Highway from Adelaide to Darwin can seem like an uneventful journey, with miles and miles of flat country only occasionally interrupted by low hills and dry creeks.
But hidden beneath the red earth are some of the biggest subsurface anomalies you've never seen.
Just north of the outback town of Marla, the layer underneath the Earth's crust called the mantle rises up 30 kilometres closer to the surface along an extensive fault system known as the Woodroffe Thrust-Mann fault.
This subterranean mountain is so large that it actually warps the Earth's gravity field. The mantle is much denser than typical continental crust. So the Woodroffe Thrust-Mann Fault is visible in gravity maps as a linear streak running east-west.”
Gravity anomalies: Bright red streaks (indicated by white arrow) show places where the Earth's mantle is 30 kilometres closer to the Earth's surface. (Supplied: Geoscience Australia)
Continuing to quote from ABC article;
“Gravitational acceleration is faster in the red areas at the core of the fault zone compared to the blue areas either side.
The difference in gravity along the fault zone is so dramatic that it has been recognised as the largest continental gravity gradient anywhere in the world.
So if you were to drop a rock on your foot on the journey from Adelaide to Darwin, better to do it at a fuel stop in Marla than while sightseeing at the border of South Australia and the Northern Territory — the lower gravity at Marla means the rock will be slightly lighter so it might hurt a little less.”
The Woodroffe Thrust-Mann Fault intersects the Bali to Bairnsdale Alignment.
Edited 1 time(s). Last edit at 02-May-18 18:43 by Robert Jameson.