Cruise inventory

RRS Challenger CH87

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Challenger (74CH)
Cruise identifierCH87
Cruise period1991-12-04 — 1991-12-19
StatusCompleted
Port of departureTroon, United Kingdom
Port of returnBarry, United Kingdom
PurposeResearch
Objectives1. The measurement of near-bed turbulence, vertical current structure, waves (especially directional spectra) and currents at two sites separated by 10km and aligned with the main tidal stream for a period of 10 days.
2. Determination of wave and current dissipation.
3. Measurement of suspended sediment flux using transmissometers, an acoustic backscatter probe and an array of drogue nets (SEDRIG).
4. The measurement of bedload transport rate and direction using STABLE and fluorescent sand tracers.
5. Determination of 3-D scale and structure of near-bed turbulent bursting events.
6. To observe the response of bedforms to bottom stress resulting from the combined action of waves and tidal currents.
7. Determination of drag partitioning, especially from drag imposed by local bedforms.
Chief scientistJon J Williams (Proudman Oceanographic Laboratory)
ProjectMAST project 0036-C, Linear sandbanks
Coordinating bodyPOL
Cruise reportRRS Challenger CH87 cruise report ch87_91.pdf — access key 'C' (0.69 MB) 
Ocean/sea areas 
GeneralNorth Sea
SpecificSouthern North Sea
Track chartsRRS Challenger CH87 cruise track — ch87_91track.pdf (00 MB) 
Measurements 
Physical oceanography 
CTD stationsQuantity: number of stations = 3
Description: Vertical profiles (hourly) obtained over a 13 hour period
Current metersQuantity: number of stations = 4
Other physical oceanographic measurementsQuantity: number of measurements = 150
Description: Radar measurements of directional wave spectra
Meteorology 
Occasional standard measurementsQuantity: number of observations = 136
Description: Met.data (wind speed/direction, wet, dry and sea temp., barometric pressure)
Geology and geophysics 
GrabQuantity: number of samples = 180
Description: samples obtained in the vicinity if fluorescent sand tracer sites
Single-beam echosoundingQuantity: number of track lines = 50
Description: tracks - PES echo-sounding survey
Long/short range side scan sonarQuantity: number of track lines = 50
Description: tracks - side scan sonar survey
Moorings, landers, buoys 
Physical oceanography 
Current meters52° 31' 29" N  3° 32' 35" E — S4 and RCM (30m) near bed currents
Current meters52° 39' 5" N  3° 38' 53" E — S4 current meter (3m) - surface flow
Current meters52° 38' 42" N  3° 38' 53" E — S4 and RCM (30m) near bed currents
Current meters52° 30' 54" N  3° 32' 59" E — S4 current meter (3m) - sureface flow
Current profiler (eg ADCP)52° 31' 12" N  3° 31' 41" E — ADCP (30m) vertical current structure
Current profiler (eg ADCP)52° 39' 11" N  3° 39' 5" E — ADCP (30m) vertical current structure
Instrumented wave measurements52° 38' 53" N  3° 39' 5" E — Waverider buoy - 1D spectra
Instrumented wave measurements52° 31' 36" N  3° 31' 54" E — Endico Wave buoy; 2D wave spectra
Other physical oceanographic measurements52° 39' 5" N  3° 39' 24" E — Steel STABLE (30m); near bed turbulence; suspended sediments
Other physical oceanographic measurements52° 37' 59" N  3° 37' 59" E — 500kg blue fluorescent sand deployed
Other physical oceanographic measurements52° 38' 5" N  3° 38' 48" E — 500kg red fluorescent sand deployed
Other physical oceanographic measurements52° 32' 5" N  3° 33' 47" E — 500kg red fluorescent sand deployed
Other physical oceanographic measurements52° 32' 30" N  3° 31' 54" E — 500kg blue fluorescent sand deployed
Other physical oceanographic measurements52° 31' 12" N  3° 32' 17" E — Pop-up STABLE (30m); near bed turbulence; suspended sediments