RRS Challenger CH78
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS Challenger (74CH) |
| Cruise identifier | CH78 |
| Cruise period | 1991-04-23 — 1991-05-09 |
| Status | Completed |
| Port of departure | Barry, United Kingdom |
| Port of return | Barry, United Kingdom |
| Purpose | Research |
| Objectives | 1. To evaluate the hydrodynamic processes controlling the resuspension of sediment at a muddy coastal site in the Irish Sea.
2. To evaluate the influence of sedimentological characteristics and geotechnical and geophysical properties of the bed on resuspension. 3. To examine the role of benthic organisms in sediment resuspension and deposition processes. 4. To determine the impact of sediment resuspension on water quality through its influence on trace metal and nutrient exchange processes. 5. To develop a detailed model of interrelating vertical current structure and suspended sediment concentration at a point site and to use this model as the basis for constructing a fine grid, three dimensional model of the observational area. |
| Chief scientist | Alan W Morris (Plymouth Marine Laboratory) |
| Cruise report |  (0.26 MB) |
| Ocean/sea areas | |
| General | Irish Sea and St. George's Channel |
| Specific | Irish Sea |
| Track charts | (0.02 MB) |
| Measurements | |
| Physical oceanography | |
| Water bottle stations | Quantity: number of deployments = 15 Description: near-bed multiple-depth water bottle sampler under test |
| CTD stations | Quantity: number of profiles = 187 |
| Current meters | Quantity: number of stations = 3 Description: 8 cm deployed & recovered |
| Other physical oceanographic measurements | Quantity: number of experiments = 26 Description: particle settling velocity measurements (QUISSET) |
| Chemical oceanography | |
| Phosphate | Quantity: number of profiles = 17 Description: near-bed multiple-depth water bottle sampler |
| Phosphate | Quantity: number of measurements = 12 Description: sediment pore water |
| Nitrate | Quantity: number of measurements = 12 Description: sediment pore water |
| Nitrate | Quantity: number of profiles = 17 Description: near-bed multiple-depth water bottle sampler |
| Ammonia | Quantity: number of profiles = 17 Description: near-bed multiple-depth water bottle sampler |
| Ammonia | Quantity: number of measurements = 12 Description: sediment pore water |
| Silicate | Quantity: number of measurements = 12 Description: sediment pore water |
| Silicate | Quantity: number of profiles = 17 Description: near-bed multiple-depth water bottle sampler |
| Alkalinity | Quantity: number of measurements = 12 Description: sediment pore water |
| Trace elements | Quantity: number of measurements = 12 Description: sediment pore water |
| Biology and fisheries | |
| Sediment traps | Quantity: number of deployments = 4 Description: (x 12 hour deployments) sediment traps - trapping efficiency/chemical analysis |
| Zoobenthos | Quantity: number of samples = 12 Description: box cores |
| Molluscs | Quantity: number of samples = 12 Description: box cores |
| Geology and geophysics | |
| Core - soft bottom | Quantity: number of deployments = 12 Description: box corer for chemical, geotechnical and biological measurements |
| Moorings, landers, buoys | |
| Physical oceanography | |
| Transparency (eg transmissometer) | 54° 7' 0" N 3° 28' 0" W — 2 transmissometers on above current meter rig |
| Transparency (eg transmissometer) | 54° 7' 0" N 3° 28' 0" W — 2 transmissometers on above current meter rig |
| Current meters | 54° 7' 0" N 3° 28' 0" W — 2 current meters - deployed 25 Apr 1991, recovered 06 May 1991 |
| Current meters | 54° 7' 0" N 3° 28' 0" W — 2 current meters - deployed 25 Apr 1991, recovered 06 May 1991 |
| Current meters | 54° 7' 0" N 3° 28' 0" W — 2 current meters - deployed 24 April 1991, recovered 07 May 1991 |
| Current meters | 54° 7' 0" N 3° 28' 0" W — 2 current meters - deployed 24 April 1991, recovered 07 May 1991 |
| Current profiler (eg ADCP) | 54° 7' 0" N 3° 28' 0" W — Sea floor ADCP - deployed 01 May 1991, recovered 02 May 1991 |
| Current profiler (eg ADCP) | 54° 7' 0" N 3° 28' 0" W — Sea floor ADCP - deployed 30 April 1991, recovered 01 May 1991 |
| Current profiler (eg ADCP) | 54° 7' 0" N 3° 28' 0" W — Sea floor ADCP - deployed 25 April 1991, recovered 06 May 1991 |
| Current profiler (eg ADCP) | 54° 7' 0" N 3° 28' 0" W — Sea floor ADCP - deployed 25 April 1991, recovered 26 April 1991 |
| Instrumented wave measurements | 54° 7' 0" N 3° 28' 0" W — Waverider - deployed 25 April 1991, recovered 06 May 1991 |
| Other physical oceanographic measurements | 54° 7' 0" N 3° 28' 0" W — STABLE - deployed 26 April 1991, recovered 06 May 1991 |
| Meteorology | |
| Other meteorological measurements | 54° 7' 0" N 3° 28' 0" W — Met. buoy - deployed 24 April 1991, recovered 07 May 1991 |
| Data held at BODC | |
| Discrete samples | |
| 187 CTD frame plus rosette sampler | Transmittance and attenuance of the water column Nitrite concentration parameters in the water column Phosphate concentration parameters in the water column Salinity of the water column Temperature of the water column Concentration of suspended particulate material in the water column Silicate concentration parameters in the water column Visible waveband radiance and irradiance measurements in the water column Density of the water column Nitrate concentration parameters in the water column Dissolved metal concentrations in the water column |
