Wednesday, 18 June 2014 Back to News


13-23 June 2014 Bay of Biscay: Project overview

Map of the areas we will be studying on this research cruise.

A team of scientists including Heather Stewart of the BGS Marine Geology and Operations Team are currently working in the Bay of Biscay to study the mini-mounds of the Ferrol Canyon and the Dangaard-Explorer Canyons. Led by Prof David Van Rooij of the University of Ghent, Belgium and working with scientists from the universities of Plymouth and Vigo (Spain) the group's aim is to understand how old the mini-mounds are and how the oceans have changed since the time they started to form to the present day; how the mounds are formed; and the biology and ecology of the mound systems. The survey follows on from work in 2007 during which hundreds of mini-mound features were observed on the canyon interfluves (the area between the canyon heads) between the Dangaard & Explorer Canyons in the UK's South-West Approaches.

Seabed bathymetry of the Explorer and Dangaard Canyons.

In 2007, the team only had time to run video cameras over 3 of these mound features, but were able to identify them as cold water coral (CWC) mounds. The CWC mounds (also known as coral carbonate mounds) are structures found in the deep sea and formed from the progressive growth and decay of reef forming hard coral species. The mounds discovered in 2007 are relatively small (hence the term 'mini-mounds') at only 100-200 m wide at their base, and 5 m high, and occur in water depths between 200-550m.

Since their discovery in 2007, the team have learned that four mini-mound provinces have been documented in this region, on the Porcupine Seabight upper slope (Irish margin), near the Dangaard-Explorer Canyon (Celtic margin), the Guilvinec Canyon (Armorican margin) and between the Ferrol and A Coruņa Canyon (Cantabrian margin). All occur within this same depth range of 200-550m and all are of similar size. How these mini-mounds relate to the better known larger and deeper CWC mounds is unknown, but the working hypothesis is that they represent some kind of start-up phase in larger mound formation.

The current survey started on June 13th when the team left Porto in Portugal onboard the Belgian research vessel, the Belgica. Also onboard are BGS engineers Iain Pheasant and Dave Wallis who are responsible for developing the new, autonomous, BGS battery-operated vibrocorer. Within the last few days, the team have drilled at several sites with up to 3 metres of core recovery (the maximum achievable using the vibrocorer). The team have also acquired more seismic profile data to complement the data collected in 2007 and have deployed video cameras to make observations of the sea floor. The team will head back to port in Belgium after completing the survey on the 23rd June.

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