HMS Protector helps scientists study tsunami threat on edge of Antarctica

Topic: Operational activity Storyline: HMS Protector

The Royal Navy is helping scientists warn of potentially devastating tsunamis by researching huge underwater volcanoes on the fringe of Antarctica.

HMS Protector used her state-of-the-art sensors to scan a series of peaks in the South Sandwich Islands, one of the most remote British territories on the planet.

The chain of volcanoes off Zavodovski Island rise hundreds of metres above the seabed. They are active with numerous seismic events every year.

A major underwater eruption could trigger a landslide and, in turn, a tsunami, with potentially devastating consequences. One such wave in August 2021 led to the evacuation of the British Antarctic Survey (BAS) research station on South Georgia – 375 miles away.

The volcanic chain was last surveyed by BAS, with whom the Plymouth-based Royal Navy icebreaker regularly works.

Scientists asked the ship to return to the area, known as the Protector Seamounts, which are named after a previous Royal Navy ship which operated in the polar region more than 50 years ago.

The data Protector gathered will be used by scientists from the British Antarctic Survey and University of Plymouth to assess the stability of the volcanoes’ flanks and look for evidence of ‘mass wasting’: huge volumes of sediment shifting, potentially triggering tsunamis which could impact people across the southern hemisphere.

“We need to understand the origin and wider significance of mass wasting in the South Sandwich Islands,” explained the project’s lead scientist Dr Jenny Gales, Lecturer in Hydrography and Ocean Exploration at the University of Plymouth.

“This is important because mass wasting events on volcanic islands represent some of the largest sediment flux events on Earth. The levels of past activity in this particular region show they are a significant geohazard, with the potential to trigger tsunamis.”

Lieutenant Commander James Winsor, HMS Protector’s senior survey officer, was impressed by the detailed scans of the underwater mountains or seamounts the ship’s sonars and software produced.

“The undersea peaks of these volcanoes rise up from depths of 2,000 metres to 90 metres in waters scarcely charted to modern standards,” he added.

Beyond helping the BAS team, the data gathered by Protector will also allow seafaring charts to be updated to the latest standards: the survey mission found a caldera (a volcano with collapsed walls following a major eruption) and one summit coming within 90 metres (295ft) of the surface – still well below the keel of any surface ship, but well within the operating depth of submarines.

Having completed her work in the South Sandwich Islands, Protector switched efforts to exploring South Georgia, the most southerly inhabited British territory on the planet, home to a small staff running the island’s museum, post office, administration and a BAS base.

The ship’s football team challenged a select South Georgia XI (drawn from government and BAS staff) organised by the ship’s Leading Physical Trainer ‘Ray’ Houghton.

The pitch is billed as the most southerly in the world. It’s also among the worst – uneven, unmown, boggy, strewn with thick tufts of grass and with a goalmouth of gravel at one end.

Despite sideways rain, snow and gale-force winds, the sailors went down to the home side who were better suited to the conditions.

“It was fantastic to get the opportunity to play on the most southerly football pitch in the world,” said Ray.

“Regardless of the score, it was about getting our people off the ship, enjoying themselves and creating an experience they can look back on with fond memories. We are very grateful to South Georgia’s government for being such good hosts.”

This is important because mass wasting events on volcanic islands represent some of the largest sediment flux events on Earth. The levels of past activity in this particular region show they are a significant geohazard, with the potential to trigger tsunamis.

Dr Jenny Gales