Cruise inventory

RRS John Murray JM15/76

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM15/76
Cruise period1976-10-28 — 1976-11-11
Port of departureSouthampton, United Kingdom
Port of returnSouthampton, United Kingdom
Objectives1) a) To recover and relay the Sizewell-Dunwich long term recording current meter
b) To recover the Marconi current meter system laid to the west of the Dunwich Bank

2) To carry out a preliminary bathymetric survey of the seabed in the area of the gas pipelines between Haisborough Bank and the Hewett gas field.

3) To resurvey selected sandwave areas in the sandwave field at Longsand Head in the Outer Thames Estuary

4) To continue the study of seabed mobility on the eastern flank of the Skerries Bank in Start Bay by:
A) Bathymetric survey using echosounder and side-scan sonar.
B) Continous seismic profiling using and EG and G Uniboom system
C) Laying 2 self-recording current meters
D) Diver observations to study the form and mobility of an individual sandwave
Chief scientistD Nicholas Langhorne (Institute of Oceanographic Sciences Taunton)
Cruise reportRRS John Murray JM15/76 cruise report edward_forbes9_76.pdf — access key 'C' (0.20 MB)  RRS John Murray JM15/76 cruise report john_murray15_76.pdf (0.43 MB) 
Ocean/sea areas 
GeneralNorth Sea
Irish Sea and St. George's Channel
Track chartsRRS John Murray JM15/76 cruise track — trk2107.html
Physical oceanography 
Water bottle stationsQuantity: number of stations = 12
Description: bottom only
Current metersQuantity: number of deployments = 2
Description: 30 days
Sea level (inc. bot. press., inverted echosounder)Description: cont.
Other meteorological measurementsDescription: sea and swell cont.
Geology and geophysics 
In-situ seafloor measurement/samplingQuantity: number of measurements = 12
Description: temp.less than 1m from bottom
Single-beam echosoundingQuantity: track kilometres = 185
Long/short range side scan sonarQuantity: track kilometres = 139
Single channel seismic reflectionQuantity: track kilometres = 37