RRS Charles Darwin CD6
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Charles Darwin (74AB) |
| Cruise identifier | CD6 |
| Cruise period | 1985-08-09 — 1985-08-27 |
| Status | Completed |
| Port of departure | Falmouth, United Kingdom |
| Port of return | Funchal, Portugal |
| Purpose | Research |
| Objectives | 1. To deploy and test 3 digital ocean bottom seismometers (DOBS).
2. To use the DOBS and 4 airguns for refraction lines to the SW of the UK; as far as possible (1) and (2) to be simultaneous. 3. In the absence of the 13.5 mm Rochester cable, to check the suitability of the CTD cable, and its winch reeving for limited depth, limited tension work. 4. Using the above cable and winch to deploy and test TOBI (a Towed Ocean Bottom Instrument), working towards an operational instrument for Darwin Cruise 9/85. 5. To deploy in GME and recover, then deploy again 2 off PUPPI (Pop-Up Pore Pressure Instruments) for recovery on Darwin Cruise 9/85 for an in-situ experiment to measure sediment porosity, for which the deep ocean tide signal provides the cyclical excitation pressure. 6. To test acoustic releases, including those for objectives 5 and 8. 7. To recover from GME a deep ocean tide gauge. 8. To deploy an inverted echo sounder for a few days and to recover. 9. To deploy and tow at a range of speeds a revised sea surface temperature/pressure fish, checking sensors and towing position and stability. 10. To test the Pore Water Sampler (PWS) using the torque balanced coring warp, with camera and sensors fitted but no water sampling tubes. 11. To do range tests on a miniature radar transponder (belonging to SPRI) mounted on a pitch-roll buoy float. 12. Calibration and intercomparison of the electromagnetic and doppler logs fitted to the ship were not possible because the Level A interface of the doppler log was not working. |
| Chief scientist | Brian S McCartney (Institute of Oceanographic Sciences Wormley Laboratory) |
| Cruise report |  (0.60 MB) |
| Ocean/sea areas | |
| General | North East Atlantic Ocean (limit 40W) |
| Specific | Great Meteor East |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Surface measurements underway (T,S) | Description: trials of SSTP recorder T only |
| Sea level (inc. bot. press., inverted echosounder) | Quantity: number of recoveries = 1 Description: Deep sea pressure recorder with temperature sensor |
| Sea level (inc. bot. press., inverted echosounder) | Description: inverted echo-sounder |
| Geology and geophysics | |
| Core - soft bottom | Quantity: number of cores = 1 |
| Bottom photography | Quantity: number of deployments = 4 |
| Long/short range side scan sonar | Quantity: number of deployments = 3 Description: towed ocean bottom instrument(TOBI),test deployments only |
| Seismic refraction | Quantity: number of deployments = 1 Description: digital ocean bottom seismograph(DOBS),noise level test |
| Other geological/geophysical measurements | Quantity: number of deployments = 2 Description: pore water pressures in sediments,2 long term deployments,(4month) |
