CE0810 (MeBo2008) Integrated National Strategic Deep-Water Seabed Drilling Campaign (INS DeepDrill)

In DeepDrill targets Ireland’s national strategic needs for deep-water seabed drilling and full core recovery at intermediate seabed penetration (down to 70 m). This is accomplished through the mobilisation of the advanced portable seafloor drilling rig MeBo financially facilitated through the European Science Foundation EuroCORES — EuroMARC CARBONATE seabed drilling programme and the Irish Shelf Porcupine Studies Group (ISPSG) of the Petroleum Infrastructure Programme (PIP) — Ireland’s joint Government-Industry research programme, which comprises hydrocarbon exploration companies active in offshore Ireland and the Petroleum Affairs Division (PAD) of the Department of Communications, Energy and Natural Resources.The key objective of the expedition was to cost-effectively collect fullrecovery core sequences in lithified substrates in support of the ESF-CARBONATE programme and ISPSG Rock Drilling program. Along the European Atlantic continental margin, cold-water corals and coldwater coral carbonate Mounds occur from northern Norway to the Gulf of Cádiz. The Mounds differ considerably in size (5-380 m) and present day ‘activity’ (covered with abundant living corals at the SW Rockall Trough margin to fully buried Mounds in the Porcupine Seabight). Up to now the carbonate stored in these Mounds has not been considered in the global carbon budget.A challenge existed to quantify the amount and flux of carbon stored in these structures. Previous Investigations of short sediment cores Revealed that all Mounds possess different growth Histories depending on the environmental setting and the involved faunal associations. These previous cores penetrated only the upper few metres of the Mounds setup limiting the research to the very late stage of mound development. By understanding how biogeochemical processes control the development of these carbonate Mounds and their response to climate change, CARBONATE (Mid Latitude carbonate systems: complete sequences from cold-water coral carbonate Mounds in the Northeast Atlantic) AIMS at quantifying their role as mid-Latitude carbonate sinks. The main aim of the CARBONATE and INS DeepDrill was to drill through several Mounds (in total six carbonate mound locations in the Porcupine-Rockall area at various locations in order to understand the role of the environmental parameters on mound formation and the role of the Mounds in the global carbon cycle. This 23 day survey took place on board the Marine Institute’s R.V. Celtic Explorer from 15th of August after 4.5 days of mobilisation of MeBo in Galway, Ireland, and ended there again on the 6th of September 2008 followed by 2 day of de-mobilisation of MeBo. In addition to the Drills and ground truthing conducted, CTD (conductivity, Temperature and depth) casts were deployed to measure variations in salinity, temperature and dissolved oxygen in the water column as well as to take water samples.