Planned maintenance — 18th January 2018 12:00 to 22nd January 2018 09:00 [more]

Cruise inventory

RRS John Murray JM13/75

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM13/75
Cruise period1975-09-23 — 1975-09-27
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
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.

Due to continuous bad weather, no useful work was possible during this cruise.
Chief scientistIan D James (Institute of Oceanographic Sciences Bidston Laboratory)
Cruise reportRRS John Murray JM13/75 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 JM13/75 cruise track — john_murray11and13and14_75track.pdf (0.04 MB)