Scientists have stumbled across a cluster of submerged volcanoes that may be at least 50 million years old off the coast of Sydney, Australia, livemint.com reported.

Using Australia new ocean-going research vessel, Professor Iain Suthers discovered four 2,000-foot volcanoes in 4,900 meters of water during a search for nursery grounds for larval lobsters. At the time the ship was routinely mapping the seafloor.

"It's ironic that we're about to get the first close-up pictures of Pluto but we had no idea about these beautiful volcanoes just off the coast of Sydney," Suthers, chief scientist for the voyage and a marine biologist at the University of New South Wales, told Time.

The volcanoes in the cluster are calderas, which form after a volcano erupts and the land around them collapses, forming a crater. The largest is 1.5 kilometers across the rim and it rises 700 meters from the sea floor.

"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," Suthers added.

These types of volcanoes are important to geoscientists because they are essentially windows into the seafloor, according to Richard Arculus, a world-leading expert on volcanoes.

"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," said Arculus, who is also a professor at the Australian National University.

According to Arculus, scientists know very little about the topography of "our backyard" because water limits their ability to learn about the arrangement of the natural and artificial physical features of an area.

"We know the surface topography of Mars better than we know our backyard because there's no water in the way," he told AFP, according to BBC News. "I think every time we turn the spotlight on the sea floor we see things that we've never seen before."

Suthers said the 94-meter Investigator that discovered the volcanoes has other capabilities that marine scientists in Australia have never had before, and the vessel will be key to unlocking the secrets of the oceans around our continent and beyond.