At least four huge underwater volcanoes, believed to be about 50 million years old, were discovered by a group of Australian scientists off the coast of Sydney, Australia recently.
Scientists theorize that the volcanoes were shaped by a series of shifts in geological plates that triggered the separation of Australia from New Zealand.
“They tell us part of the story of how New Zealand and Australia separated around 40 million 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,” explained Professor Richard Arculus, a volcano expert at the Australian National University, as quoted by The Guardian.
The team composed of 28 scientists, onboard the Investigator research vessel, was scouring the seabed for lobster larvae when they discovered the volcano cluster last month, the Guardian added.
The range of ancient, inactive volcanoes was found more than 150 miles off the coast of Sydney, according to the Morning Bulletin. It was found about three miles beneath the ocean’s surface and measures 12 miles by four.
It added that the largest of the four volcanoes measured nearly a mile wide and rising some 2,000 ft above the sea floor.
Scientists described the volcanoes as “calderas” or has enormous bowl-like shaped craters that were formed when a volcano erupts and the land around it collapses.
Arculus said the four volcanoes were extinct and had no chance of erupting again.
“These guys have been dead for a long time,” he told the Morning Bulletin. “Volcanic activity in the Tasman Sea is extinct,” he added.
Meanwhile, Professor Iain Suthers, a marine biologist at the University of NSW, told the Guardian the area were the cluster was found was thought to be “billiard-table flat” but the superior mapping capability of the Investigator uncovered the calderas.
Australia’s Investigator vessel took its first sea tests in March. It can map the seafloor at any depth. In comparison, its predecessor, the Southern Surveyor, can only map 3,000 meters.