Cruise inventory

RRS John Murray JM5/75

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM5/75
Cruise period1975-04-04 — 1975-04-15
StatusCompleted
Port of departureBarry, United Kingdom
Port of returnLowestoft, United Kingdom
PurposeResearch
Objectives1. 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 scientistD Nicholas Langhorne (Institute of Oceanographic Sciences Taunton)
Cruise reportRRS John Murray JM5/75 cruise report john_murray5_75.pdf — access key 'C' (0.27 MB) 
Ocean/sea areas 
GeneralNorth Sea
Irish Sea and St. George's Channel
Track chartsRRS John Murray JM5/75 cruise track — trk1617a.html RRS John Murray JM5/75 cruise track — trk1617b.html
Measurements 
Physical oceanography 
Other physical oceanographic measurementsQuantity: number of profiles = 7
Description: sound velocity stations
Geology and geophysics 
In-situ seafloor measurement/samplingQuantity: number of dives = 10
Description: sampling by divers
Multi-beam echosoundingQuantity: track kilometres = 926
Long/short range side scan sonarQuantity: track kilometres = 926