Using a new research vessel, a team of Australian researchers discovered a group of extinct volcanoes believed to be at least 50 million years old off the coast of Sydney, the University of New South Wales (UNSW) announced on Monday.
Chief scientist Iain Suthers, a marine biologist and professor at UNSW Australia, and his team found the volcano cluster approximately 250 kilometers (155 miles) off the coast of the capital, in roughly 4,900 meters (16,000 feet) of water while hunting for a lobster nursing ground.
The cluster includes four extinct volcanoes known as calderas, which the authors explained form after a volcano erupts, causing the surrounding land to collapses and form a crater. The largest of the calderas is 1.5 km (0.9 miles) across the rim and rises 700 meters (about 2,300 meters) above the sea floor. The cluster as a whole is 20 km (12.4 miles) long and 6 km (3.7 miles) wide.
In a statement, Professor Suthers called the voyage “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.”
Discovery made possible thanks to new research vessel
He and more than two dozen colleagues departed from Brisbane on June 3 on board the research vessel Investigator, mapping the seafloor during a voyage that concluded on June 18 when they reached Sydney. During the journey, the ship was also routinely mapping the seafloor.
Volcano expert Professor Richard Arculus from the Australian National University, an igneous petrologist and one of the scientists involved in the research project, said that this specific type of volcano were essential to geoscientists because they would help explain how Australia and New Zealand separated between 40 million and 80 million years ago.
He added that their discovery would “help scientists target future exploration of the sea floor to unlock the secrets of the Earth’s crust,” and that they were only just discovered because of the improved sonar technology on the new vessel, which can map the sea floor to greater depths than was previously possible.
Professor Suthers noted that Investigator is capable of many things that weren’t possible with previous research vessels. For example, he said it can “send and receive data while we’re at sea, which meant the team back on base at UNSW in Sydney could analyze the information we were collecting at sea and send back their analysis, along with satellite imagery, so we could chase the eddies as they formed.”
“This is the first time we’ve been able to respond directly to the changing dynamics of the ocean and, for a biological oceanographer like me, it doesn’t get more thrilling,” he added. “It was astounding to find juvenile commercial fish species like bream and tailor 150 kilometers offshore, as we had thought that once they were swept out to sea that was end of them. But in fact these eddies are nursery grounds along the east coast of Australia.”