Australian scientists have witnessed the rare eruption of an Antarctic volcano off the coast of the frozen continent.

The scientists, from Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), filmed the volcanic event by chance while aboard research vessel “Investigator” studying the fringe of Antarctica’s Heard Island.

The crew, working in conjunction with the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS), were actually looking to study underwater volcanoes before the land-based variety caught their attention.

Heard Island, a remote sub-Antarctic region, is home to Big Ben, an active volcano which is believed to have only erupted three times since the turn of the century.

Given the island’s isolation, viewing Big Ben – which is mostly covered in ice throughout the year – during an eruption is considered a geoscientific rarity. Often, satellite images provide the only evidence that an eruption has occurred.

Chief scientist aboard The Investigator, IMAS professor and geophysicist Mike Coffin, said on Monday it was a great thrill to film the 2,745-meter volcano in action, becoming one of the few people in human history to have witnessed it erupting.

“We have 10 excited geoscientists aboard Investigator, and our enthusiasm has spread to our 50 shipmates,” Coffin said in a CSIRO press release on Monday.

The crew, based 4,100 km southwest of the Western Australian city of Perth, are only three weeks into their 58-day research voyage.

Despite the trip barely getting underway, the researchers claim to have already uncovered “50 potential underwater hydrothermal plumes,” which may help establish whether active underwater volcanoes – which create these plumes – form the foundation for life in the Southern Ocean.