Submerged Extinct Volcano Cluster Discovered Off Coast of Sydney

Posted on July 15, 2015

Cluster of extinct volcanoes found off the coast of Sydney

Scientists from the University of New South Wales have discovered a cluster of extinct submerged volcanoes off the coast of Sydney, Australia. The four volcanoes are believed to have gone extinct about 50 million years ago. The volcanoes are located about 250 kilometers off the coast of Sydney.

The volcanoes are calderas which form after a volcano erupts and collapses the land around them leaving a large crater. The largest of the four volcanoes is 1.5 kilometers (.93 miles) across its rim. It rises 700 meters from the sea floor. The cluster itself is 20 kilometers long and six kilometers wide

The UNSW researchers made the discovery during a hunt for larval lobster nursery grounds. Larval lobsters were also found. The research was led by UNSW Australia marine biologist Professor Iain Suthers.

Professor Suthers says in a statement, "The voyage was enormously successful. Not only did we discover a cluster of volcanoes on Sydney's doorstep, we were amazed to find that an eddy off Sydney was a hotspot for lobster larvae at a time of the year when we were not expecting them."

Professor Richard Arculus, a volcano expert from the Australian National University, says the volcanoes are like windows into the seafloor. He says, "They tell us part of the story of how New Zealand and Australia separated around 40-80 million years ago and they'll now help scientists target future exploration of the sea floor to unlock the secrets of the Earth's crust. They haven't been found before now because the sonar on the previous Marine National Facility (MNF) research vessel, Southern Surveyor, could only map the sea floor to 3,000 metres, which left half of Australia's ocean territory out of reach."

Here is a video showing a 3D fly through of the ancient volcanoes:



Image: Australia Marine National Facility