RRS John Murray JM8/71

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM8/71
Cruise period1971-06-23 — 1971-07-14
Port of departureFairlie, United Kingdom
Port of returnOban, United Kingdom
Objectives1. To investigate, in detail, sedimentary basins and associated major fractures at the southern margin of the Minch, i.e. between northern Skye and the Outer Hebrides: seismic refraction and reflection lines to be shot over the basis to determine the nature and extent of their sedimentary infills with sparker and magnetometer profiles supplying information on near-surface geology and on the margins of the basins; sea-bed gravimeter observations to be made, primarily in the area of Loch Snizort, to clarify the known, but ill-defined, gravity anomaly occurring over one of the basins.
2. To further our investigation of the Malin centre, begun on cruise of M.V. Surveyor in 1970, by sea-bed gravimetry.
3. To take some sea-bed gravity readings in Lough Foyle for Professor Murphy of the Institute of Advanced Studies, Dublin.
Chief scientistAdam C McLean (University of Glasgow Department of Geology)
Cruise reportRRS John Murray JM8/71 cruise report john_murray8_71.pdf (0.24 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
Track chartsRRS John Murray JM8/71 cruise track — trk1332.html RRS John Murray JM8/71 cruise track — trk1838.html
Geology and geophysics 
Multi-beam echosoundingQuantity: track kilometres = 1389
Single channel seismic reflectionQuantity: track kilometres = 1389
Seismic refractionQuantity: number of track lines = 4
Description: Each approximately 15 kilometres
Magnetic measurementsQuantity: track kilometres = 1389