CP2 Regional Sea Boundaries: Atlantic North-West Approaches, Rockall Trough and Faeroe/Shetland Channel, Scottish Continental Shelf, Offshore 1:250k: Darwin, Faroe Bank, Flett, Foula, Judd, Kennedy, Rona, Rosemary Bank, Sula Sgeir, Wyville Thomson, Offshore 1:500k: Central Hatton, Faroe Shetland Basin, North Hatton, North Rockall Basin, SeaVoX Sub-Ocean: NORTHEAST ATLANTIC OCEAN (40W)
This Rockall Consortium marine geophysical and sampling survey took place in May/June 1998 in the area of West Shetland, Northern Rockall Trough and Hatton Bank on board RRS Challenger. Subsurface seismic data were collected with an airgun and sparker. Bathymetry data was collected with a Simrad EA500. Seabed samples were collected with a gravity corer. Technical details of the survey are contained in BGS Report WB/92/42C, https://nora.nerc.ac.uk/id/eprint/529921/. https://mapapps2.bgs.ac.uk/geoindex_offshore/home.html?cruise=1998/1_RCK&.
NAVIGATION (Positioning System): A VERIPOS DGPS system was used. The system comprised two Sercel NR103 DGPS receivers with corrections from either an HF radio link or via satellite using a link into the vessel's satcom aerial. Data from the NR103 receivers was processed and logged by a Qubit TRAC IV navigation processor/logger. BATHYMETRY: This was a vessel installed Simrad EA500. SEISMIC SYSTEMS: AIRGUN: The source was a cluster array of four 40 cu inch Bolt 600B guns with wave shape kilts, towed at a depth of 2m. For the majority of the time, including all but one line of the survey, two guns were used. The hydrophone was a 30m, two channel Geomechanique, with both channels summed to give a single output. The raw data was recorded and processed using a CODA DA200 system. The processed data were recorded on Exabyte tape. The processes applied included TVG and TVF. SPARKER: The source consisted of an EG&G nine candle sparkarray fitted with multi-tip candles arranged in groups of three, with an energy of 500J available throught each group. For shallower sites 1000J firing through six candles was used, increasing to 1500J through nine candles at deeper sites. The firing rates varied with water depth to obtain the optimum configuration of airgun/sparker. The sparker was given priority for the site surveys, this priority being reversed for the regioanl survey over Hatton Bank. The hydrophone was a 10m, 7 channel Teledyne with a number of channels (normally 6) summed to give optimum output. The raw data was recorded and processed using a CODA DA200 system. The processed data were recorded on Exabyte tape. The processes applied included TVG and TVF. SEDIMENT SAMPLING: A gravity corer with 1 ton weight and 3m core barrel was used to collect sediment samples. For more detailed information see the Report, https://nora.nerc.ac.uk/id/eprint/529921/.
unrestricted use, copyright acknowledgement
Geophysical and Sampling Survey 1998/1_RCK: West Shetland, Northern Rockall Trough, Hatton Bank (28/05/1998 to 17/06/1998)
Airgun/Sleeve Gun, Echo Sounder, Sparker
Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced British Geological Survey materials "Contains British Geological Survey materials ©UKRI [year]"