Cruise inventory

RRS John Murray JM11/75

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM11/75
Cruise period1975-08-15 — 1975-08-21
StatusCompleted
Port of departureLiverpool, United Kingdom
Port of returnBarry, United Kingdom
PurposeResearch
Objectives1) To study the frontal region, situated in the southern St George's Channel, by continously sampling surface conductivity and temperature, by taking vertical profiles of conductivity and temperature and by developing Batfish to measure conductivity and temperature against depth while the vessel was moving.

2) To study internal tides in the Celtic Sea, especially in the area where the depth of thermocline decreased. This entailed deploying recording current meter and thermistor chain rigs.

3) To continue a study of the circulation, long term variability and physical oceanography of the area by comparing the results from the above equiptment with those from previous experiments.

4) To provide data for a cotidal chart and energy budget of the area by deploying 2 current meter rigs, one off St Ives and one near Lundy, to fill in the gaps of previous experiments.

5) To test hardware developments to recording current meters- an elapsed time counter and a new bottom frame- and the effects of sampling the data frequently.
Chief scientistM John Howarth (Institute of Oceanographic Sciences Bidston Laboratory)
Cruise reportRRS John Murray JM11/75 cruise report john_murray11and13and14_75.pdf — access key 'C' (0.66 MB) 
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
Track chartsRRS John Murray JM11/75 cruise track — john_murray11and13and14_75track.pdf (0.04 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: track kilometres = 1530
CTD stationsQuantity: number of stations = 96
Description: CTD profiles.
Current metersQuantity: number of deployments = 7
Description: 55 days
Moorings, landers, buoys 
Physical oceanography 
Current meters51° 27' 59" N  6° 34' 59" W — Current meter deployed at station 'B'
Current meters51° 56' 29" N  6° 46' 59" W — Current meter deployed at station 'C'
Current meters51° 18' 59" N  4° 43' 59" W — Current meter deployed at station 'D'
Current meters51° 54' 59" N  5° 57' 59" W — Current meter deployed at station 'H'
Current meters52° 4' 59" N  5° 45' 59" W — Current meter deployed at station 'J'
Current meters50° 27' 0" N  5° 54' 0" W — Current meter deployed at station 'E'
Current meters51° 39' 59" N  6° 4' 59" W — Current meter deployed at station 'A'