RRS John Murray JM5/75
Cruise summary report
| Cruise Info. | |
| Ship name (ship code) | RRS John Murray (74MJ) |
| Cruise identifier | JM5/75 |
| Cruise period | 1975-04-04 — 1975-04-15 |
| Status | Completed |
| Port of departure | Barry, United Kingdom |
| Port of return | Lowestoft, United Kingdom |
| Purpose | Research |
| Objectives | 1. To establish a research area in a sandwave field where studies of stability may be in relation to meteorological conditions, and comparisons made with sandwaves studies at Longsand Head, Outer Thames Estuary.
2. To carry out sea trials of the Sonardyne 'Rangemaster' relative position-fixing system using sea bed transponders. 3. To continue the study of sandwaves and associated dune bedforms at Longsand Head, with particular reference to the reformation of sandwaves in the PLA trial dredged channel. 4. To continue the study of sand ribbons associated with Shipwash Bank in order to determine their relevance as paths of sediment transport. 5. To carry out trials with 'Automatic Gain Control' circuit boards fitted to the EG & G Dual Channel sidescan sonar. 6. To carry out an acceptance trial of the Plessey Sound velocity meter. 7. To observe sandwaves in different environments to study the association of dune bed forms. |
| Chief scientist | D Nicholas Langhorne (Institute of Oceanographic Sciences Taunton) |
| Cruise report |  (0.27 MB) |
| Ocean/sea areas | |
| General | North Sea Irish Sea and St. George's Channel |
| Track charts |  |
| Measurements | |
| Physical oceanography | |
| Other physical oceanographic measurements | Quantity: number of profiles = 7 Description: sound velocity stations |
| Geology and geophysics | |
| In-situ seafloor measurement/sampling | Quantity: number of dives = 10 Description: sampling by divers |
| Multi-beam echosounding | Quantity: track kilometres = 926 |
| Long/short range side scan sonar | Quantity: track kilometres = 926 |
