State’s research ship completes Atlantic Ocean survey

Iceberg footprints and underwater mountain among findings by MV Celtic Explorer

Image of a 3D animation of a  3.7km high underwater mountain, which is more than 140km long, on the Charlie-Gibbs Fracture Zone on the Mid-Atlantic Ridge. The image is part of a survey of the Atlantic Ocean conducted by the State’s research ship, the MV Celtic Explorer.   Photograph: Marine Institute
Image of a 3D animation of a 3.7km high underwater mountain, which is more than 140km long, on the Charlie-Gibbs Fracture Zone on the Mid-Atlantic Ridge. The image is part of a survey of the Atlantic Ocean conducted by the State’s research ship, the MV Celtic Explorer. Photograph: Marine Institute

Footprints of icebergs moving across the seabed, an ancient glacial moraine and a mountain higher than Carrauntoohil in Co Kerry have been mapped across the Atlantic by a team of scientists on board the State's research ship, the MV Celtic Explorer.

The survey, which is said to be a "world first" in taking a dedicated transect of an ocean floor, followed the route taken by ships dropping the first transatlantic telecommunications cable between Ireland and Newfoundland in Canada in 1857.

"We know now why that first cable didn't last," Marine Institute geophysicist Tommy Furey said, outlining the details of the three-dimensional seabed images gathered during the week-long survey.

There were five attempts to lay that first communications link between the US and Europe, and the ships had little of the hydrographic information now available to show the hazards involved - relying instead on lead line soundings every 200km.

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The MV Celtic Explorer team used the latest multi-beam echo sounder technology in the survey, which allowed features already identified in satellite images to be charted in far greater detail than they could have been even 15 years ago.

Along with some 235sq km of iceberg-scarred seabed, the survey mapped a 15 km-long “downslope” believed to be associated with the last glaciation some 20,000 years ago.

It also charted a 3.7km high underwater mountain, which is more than 140km long, while crossing the Charlie-Gibbs Fracture Zone on the Mid-Atlantic Ridge.

More than 10,000sq km of the Atlantic was covered in under a week.

Ship’s research

The Irish ship has for the last five years been involved in research on cod stocks off Newfoundland.

It was returning from one such trip when it placed six scientists on board from the Marine Institute, Geological Survey of Ireland (GSI), the Fisheries and Marine Institute of Memorial University of Newfoundland, Canada, the US National Oceanic and Atmospheric Administration, and the Portuguese Institute for Sea and Atmosphere to conduct the survey.

The State has already built up expertise in seabed mapping through its Infomar programme, run by the Marine Institute and GSI.

Marine Institute chief executive Dr Peter Heffernan said the State hoped to build on this survey next year.

An Atlantic Ocean research alliance involving the State, the US and Canada was pioneered by the Marine Institute in 2013.

The results of the “Atlantic Transect”, as the survey is known, will be presented at the Harnessing Our Ocean Wealth conference in Cork on July 10th-11th.

Lorna Siggins

Lorna Siggins

Lorna Siggins is the former western and marine correspondent of The Irish Times