The volcanoes are about 50 million years old

Jul 13, 2015 12:03 GMT  ·  By
Underwater volcanoes discovered near the city of Sydney in Australia
2 photos
   Underwater volcanoes discovered near the city of Sydney in Australia

This Monday, an international team of researchers announced the discovery of a cluster of ancient volcanoes off the coast of the state of New South Wales in Australia, not far from the city of Sydney. 

The four recently found underwater volcanoes, whose location on the ocean floor is revealed in the image below, sit at a distance of 250 kilometers (150 miles) from the Australian shoreline and at a depth of some 4,900 meters (16,000 feet).

The volcanoes are spread over 20 kilometers (12.5 miles) and are estimated to have formed 50 million years ago, explains researcher Richard Arculus with the Australian National University in Canberra.

The largest of the bunch towers over the ocean floor at a height of 700 meters (2,300 feet) and its crater measures an impressive 1.5 kilometers (1 mile) across. Given its size, it's a wonder it took scientists this long to zoom in on it and its companions.

Specialists at the Australian National University and other research institutes plan to visit the volcanoes again in the near future and study them in detail in an attempt to shed new light on our planet's history.

“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,” said Richard Arculus.

The volcanoes were discovered quite by chance

In a report detailing their work, the team of scientists who identified these previously undocumented ancient volcanoes off the coast of New South Wales, Australia, explain that the cluster was found while scanning the local ocean floor with the help of a sonar.

Interestingly, the researchers were not purposely looking to find any new underwater landscapes when they happened to come across the volcanoes. Rather, they were mapping the ocean floor to identify potential nurseries for young lobsters.

The expedition began on June 3 and ended on June 18 of this year. It involved scientists from a total of 28 institutes, and the ocean floor was mapped from aboard a research vessel dubbed the Investigator.

In case anyone was wondering, the reason the volcanoes were not spotted during previous ocean floor mapping initiatives was that the sonars used in the past could only reach a depth of 3,000 meters (9,850 meters) and so failed to pick up on them.

Sonar view of the volcanoes
Sonar view of the volcanoes

Photo Gallery (2 Images)

Underwater volcanoes discovered near the city of Sydney in Australia
Sonar view of the volcanoes
Open gallery