This dataset consists of silicon isotope data from deep-sea sediment cores taken off southeast Iceland. Samples of sea sponges were collected using piston cores and sediment cores aboard the RV Celtic Explorer in 2008 and dried or frozen for transportation. Organic matter was removed and samples were preserved for later analysis. Sample analysis occurred in 2012 as part of a comprehensive study of the carbon cycle. The data collected form the field component of the NERC-funded project "Unravelling the carbon cycle using silicon isotopes in the oceans". The project aimed to investigate deep sea sponges and the silicon they produce, in an effort to piece together the links between the supply of vital nutrients in different parts of the ocean and the crucial role other marine organisms play in absorbing CO2 from the atmosphere and storing it in deep sea sediments as organic carbon. The Discovery Science project was composed of New Investigators (FEC) Grant reference NE/J00474X/1 led by Dr. Katherine Rosemary Hendry of Cardiff University, School of Earth and Ocean Sciences. The project ran from 26 January 2012 to 30 September 2013. The silicon isotope data have been received by BODC as raw files, and will be processed and quality controlled using in-house BODC procedures and made available online in the near future. The raw files are available on request.

This dataset includes physical, biological and biogeochemical measurements of both the water column and seabed sediments. Hydrographic data include temperature, salinity, attenuance, dissolved oxygen, fluorescence, photosynthetically active radiation (PAR), sound velocity and current velocities, while biogeochemical analyses of water samples provided measurements of nutrients and biological sampling provided measurements of zooplankton abundance. A large number of benthic parameters were measured, including concentrations of substances such as nutrients, metals and carbon in both sediments and sediment pore waters. Benthic fauna were also studied, while rates of sedimentation flux were quantified. These oceanographic and benthic data were supplemented by satellite ocean colour imagery. The data were collected in the North Atlantic Ocean at the Mouth of Rockall Trough, Hatton-Rockall Basin and the Flank of Feni Drift between August 1997 and June 1999 over four cruises, comprising a preliminary site assessment (CD 107 August, 1997) followed by two process cruises (CD 111, April-May 1998, and CD 113, June-July 1998). A further cruise (CH 143) was part-funded by BENBO to retrieve moorings. The data were collected using a variety of instrumentation, including shipboard deployment of conductivity-temperature-depth (CTD) profilers with attached auxiliary sensors, benthic samplers, landers, cameras and incubation chambers, water samplers and continuous underway sensors. These were supplemented by moored sensor and satellite data. The BENBO programme was led by the Scottish Association for Marine Science/Dunstaffnage Marine Laboratory involved researchers from Southampton Oceanography Centre, Scottish Universities Research and Reactor Centre, Plymouth Marine Laboratory, Lancaster University, Leeds University, Edinburgh University, Cambridge University and the University of Wales, Bangor.

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing well over 1000 parameters. There are data from over 1000 conductivity-temperature-depth (CTD)/rosette stations, over 440 core profiles, over 180 sediment trap samples, over 140 net hauls and much, much more. The primary study area was a box extending to the base of the slope from Vigo to Cap Finistere. However, data are included from both further offshore (filament tracking) and from the Portuguese Margin. Measurements were taken from November 1996 to October 1999 during 33 cruise legs, involving research vessels from seven nations. Data were collected using a variety of equipment and techniques, including expendable bathythermographs (XBTs), turbulence probes, CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and a comprehensive water sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and phosphate uptake experiments are also included in the dataset, as are bathymetric data from multibeam (swath) surveys, coastal upwelling measurements and data from moored instruments and benthic landers. The dataset also includes imagery from satellites, seabed photography and X-ray photographs of core samples. The aim of the project was study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. The project brought together over 100 scientists from 40 research centres and universities throughout Europe. The British Oceanographic Data Centre (BODC) is assembling the data sets collected during OMEX II into its project database system and the data set is also available on CD-ROM.

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing over 1000 parameters. There are data from over 1650 conductivity-temperature-depth (CTD)/rosette stations, over 300 core profiles, over 370 sediment trap samples and much, much more. Most of this effort was directed at the region of the east Atlantic margin between La Chapelle Bank and the Goban Spur (between France and Ireland). In addition, there were two secondary areas of interest: the Norwegian Shelf Break just off Tromso and the Iberian Margin, either off Vigo or in the vicinity of the Tagus estuary. Measurements were collected from April 1993 until the end of December 1995 during 55 research cruise legs. Data were collected using a variety of equipment and techniques, including expendable bathythermography (XBTs), CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and comprehensive water and air sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and trace metal experiments are also included in the dataset, as are bathymetric data from the British Oceanographic Data Centre (BODC) GEBCO digital Atlas, air-sea flux measurements and data from moored instruments and benthic landers that were deployed for periods from a few weeks to a year. The dataset also includes imagery from satellites, water column and seabed photography, scanning electron micrographs and X-ray photographs. FORTRAN source code for biogeochemical models developed during OMEX I is also included. The aim of the project was to study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. OMEX I involved scientists from 30 institutions in 10 countries. BODC is assembling the data sets collected during OMEX I into its database system and the data are also available on CD-ROM.