Cruise inventory

RRS Discovery D46_leg2

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD46_leg2
Cruise period1972-05-04 — 1972-05-24
Port of departureBarry, United Kingdom
Port of returnPlymouth, United Kingdom
ObjectivesLeg 2 of 3 of D46

1) Test newly built componets of the 'Minimode' acoustic float tracking system
2) To get the 'Minimode' acoustic float tracking system fully functional
3) To operate the 'Minimode' acoustic float tracking system on a large enough scale to show whether the propsed 1973 experiment is feasible.
4) Electric hydrographic winch trials
5) Current meter Spar trials

Calibration runs for the electromagnetic logs were made, relative to a surface drogue
Chief scientistJohn C Swallow (National Institute of Oceanography)
Cruise reportRRS Discovery D46_leg2 cruise report d46.pdf — access key 'C' (0.99 MB) 
Ocean/sea areas 
GeneralBristol Channel
Track chartsRRS Discovery D46_leg2 cruise track — d46track_leg2and3.pdf (0.02 MB) 
Physical oceanography 
Water bottle stationsDescription: T surface only
CTD stationsQuantity: number of stations = 15
Description: Rosette multisampler stations
Subsurface temperature and salinity measurementsQuantity: number of samples = 48
Description: From 45 stations. Measurements taken from 50m to 2800m depth
Neutrally buoyant floatsQuantity: number of experiments = 3
Description: Serial no.233 probable depth 1830-1875m, no.234 1790-1835m, and no.235 1775-1815m. Nominal depth of 1800m.
Other physical oceanographic measurementsQuantity: number of measurements = 16
Description: Dip samples taken with the protas (probe recording ocean temperature and shear). Measurements of velocity and temperature gradients down to a depth of 1500m. Trials carried out with equipment
Biology and fisheries 
Gear researchQuantity: activity duration in hours = 74.5
Description: Electric (4.2 hours) and mechanical (70 hours) hydrographic winch trials
Incident radiation
Occasional standard measurements
Geology and geophysics 
Multi-beam echosoundingQuantity: number of measurements = 5
Description: Sound sources were tracked simultaneously during the acuostic trials of the MODE Float Tracking system. Echo soundings were taken on passage in deep water.
Moorings, landers, buoys 
Physical oceanography 
Current meters47° 32' 17" N  8° 23' 24" W — Mooring no.108. Reocvered from station 7775 after 148 days in the water
Current meters53° 33' 5" N  18° 35' 29" W — Mooring no.118 containing 3 current meters. Recovered from station 7895.
Current meters52° 28' 59" N  17° 45' 0" W — Mooring no.117 containing 4 current meters. Recovered from station 7889.
Current meters47° 29' 53" N  8° 24' 36" W — Mooring no.116 laid to test a 5.1 kHz transponder. Recovered from station 7869, 9 day period. 2 current meters incorporated into mooring