Ancient ‘mirror image’ of Great Barrier Reef discovered off northern Australia

Jackson Mccaffrey a University of Melbourne PhD student (supervised by A/Prof Stephen Gallagher and A/Porf Malcolm Wallace) has used detailed subsea seismic data and information from cores obtained from IODP Expedition 356 to discover an ancient great barrier reef off Australia’s coast.

Our research shows that a 2000 km long reef similar to the present east coast Great Barrier Reef persisted and expanded for millions or years around 15 million years ago off North West Australia and pretty much disappeared by 10 million years ago.

Nevertheless, the modern “less great” remnants of this reef are still present today as smaller patches off the Kimberley coast, the Rowley Shoals, Ningaloo Reef and the Houtman-Abrolhos reefs.

What could have led to the death of the North West Australian Great Barrier Reef?

We suggest that a combination of ocean/climate change and subsidence (the region started sinking at a very fast rate just prior to reef demise) caused the drowning of this huge feature, leaving a few small modern reefs today.

Published in the journal Global and Planetary Change