RRS John Murray JM15/76
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS John Murray (74MJ) |
| Cruise identifier | JM15/76 |
| Cruise period | 1976-10-28 — 1976-11-11 |
| Status | Completed |
| Port of departure | Southampton, United Kingdom |
| Port of return | Southampton, United Kingdom |
| Purpose | Research |
| Objectives | 1) 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 scientist | D Nicholas Langhorne (Institute of Oceanographic Sciences Taunton) |
| Cruise report |  (0.20 MB) (0.43 MB) |
| Ocean/sea areas | |
| General | North Sea Irish Sea and St. George's Channel |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Water bottle stations | Quantity: number of stations = 12 Description: bottom only |
| Current meters | Quantity: number of deployments = 2 Description: 30 days |
| Sea level (inc. bot. press., inverted echosounder) | Description: cont. |
| Meteorology | |
| Other meteorological measurements | Description: sea and swell cont. |
| Geology and geophysics | |
| In-situ seafloor measurement/sampling | Quantity: number of measurements = 12 Description: temp.less than 1m from bottom |
| Single-beam echosounding | Quantity: track kilometres = 185 |
| Long/short range side scan sonar | Quantity: track kilometres = 139 |
| Single channel seismic reflection | Quantity: track kilometres = 37 |
