RV Jean Charcot Tourbillon II

Cruise summary report

Cruise Info. 
Ship nameRV Jean Charcot
Cruise identifierTourbillon II
Cruise period1979-08-28 — 1979-09-10
Port of departureBrest, France
Port of returnBrest, France
The ship sailed for the region around 46° 59'N, 14° 48'W which had been identified as a likely eddy or Tourbillon area by a drifting satellite buoy. XBTs were launched at hourly intervals once the continental shelf had been crossed. Stations 6 and 7 of the Tourbillon array were laid on the 30th August. The ship then moved to the central region of the array and carried out a "Sea-beam" overnight in order to find a smooth region 10miles square to lay more stations. Stations 1 and 3 were laid on 31st and 4 and 5 on 1st. Station 10 was laid on 2nd September and the first MAFF (station 9) was laid in 4800m of water. The second MAFF station laid the next evening and an intensive echo- and sea-beam survey was done of the region around the proposed site. On 4th - 8th the Jean Charcot undertook a joint CTD survey with the Noroit to 4000m of the Tourbillon array region. 12 water samples were taken eaach day during this CTD survey. A "near-bottom" CTD dip was made near Tourbillon 10 and 2 hydrophone dips were made.

1) Tourbillon array was laid as planned.
2) First CTD grid of the water masses of the array region completed.
3) 11 free drifting floats were launched.
4) The float tracking system was successful, with a maximum working range of 125 miles.
Chief scientistJohn W Ramster (Ministry of Agriculture, Fisheries and Food Lowestoft Fisheries Laboratory)
Cruise reportRV Jean Charcot Tourbillon II cruise report jean_charcot_aug79.pdf (0.13 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificWithin 30 miles of 46.59', 14.48', the centre of the Tourbillon Current meter array
Physical oceanography 
Water bottle stationsQuantity: number of samples = 60
Description: 12 water samples were taken each day during the CTD survey
CTD stationsQuantity: number of surveys = 1
Description: A CTD grid was created during the cruise in the area of the array.
CTD stationsQuantity: number of profiles = 1
Description: "near-bottom" CTD dip
Current profiler (eg ADCP)Quantity: number of deployments = 11
Description: Free drifting floats were launched during the cruise. Most showed signs of a clockwise drift.
Biology and fisheries 
Gear researchQuantity: number of deployments = 1
Description: A float tracking system was tested, a working range of 125 miles was found possible at this stage of the experiment.
Geology and geophysics 
Multi-beam echosoundingQuantity: number of surveys = 2
Description: overnight sea-beam and echosound