Sydney coast
Australian scientists said Monday they discovered a cluster of volcanoes off the Sydney coast. In this photo, dated March 2014, a wave-like cloud looms over Sydney's Manly Beach during an afternoon storm front. Reuters/Will Burgess

A search for lobster larvae has led to the discovery of four extinct volcanoes over 155 miles off Sydney's coast, Australian scientists said Monday. The volcanoes are estimated to be about 50 million years old and can help provide an insight into the nature of the sea floor in the region, and the separation of present-day Australia and New Zealand.

The submerged cluster of volcanoes are calderas, which are formed by the collapse of land after a volcanic eruption, scientists from the Australian National University (ANU) and the University of New South Wales (UNSW) said, in a press release. The cluster is over 12 miles long and about 4 miles wide with the largest caldera stretching about a mile long and rising 700 meters (about 2,300 feet) from the sea floor. The base of the volcanoes are located at a depth of about 4,890 meters and they rise to about 3,998 meters.

"They tell us part of the story of how New Zealand and Australia separated around 40 to 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," Professor Richard Arculus, from the university’s Research School of Earth Sciences, said, in the statement. He called the cluster as “windows into the sea floor.”

The discovery was an exciting one, according to Iain Suthers, a professor at the University of New South Wales and a marine biologist. "There on the screen were these four incredible volcanoes looking like something off the front cover of a geology textbook...if you could drain the ocean it would be magnificent to see for a few seconds, it's a remarkable structure," Suthers reportedly said.

Arculus explained that the cluster was not found earlier because Southern Surveyors, the previous Marine National Facility research vessel, could only map the seafloor to a depth of 3,000 meters. The extinct volcanoes were discovered by Investigator -- Australia’s new ocean-going research vessel commissioned by the Commonwealth Scientific and Industrial Research Organisation.

The voyage that began on June 3 from Brisbane and concluded on June 18 in Sydney involved 28 scientists from universities across Australia.