Planned maintenance — 18th January 2018 12:00 to 22nd January 2018 09:00 [more]

Cruise inventory

RRS John Murray JM3/69

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM3/69
Cruise period1969-04-08 — 1969-04-22
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
ObjectivesThe primary aim of Cruise 3/69 was to make a seismic-refraction survey of two sedimentary troughs, one lying north-west, and one south-east of Arran. The general structure of the area had been determined previously by sea-bottom gravity-meter and magnetic surveys and it was hoped the refraction results would assist in identifying the geological formations present. It was planned to use time surplus to this programme for seismic profiling and magnetics in areas of special geological interest within the Firth; and (as an insurance against failure of the refraction programme) some reconnaissance lines to the west of Kintyre were planned, but did not have to be run.
Chief scientistAdam C McLean (University of Glasgow Department of Geology)
Cruise reportRRS John Murray JM3/69 cruise report john_murray3_69.pdf — access key 'C' (0.40 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Track chartsRRS John Murray JM3/69 cruise track — trk1330.html RRS John Murray JM3/69 cruise track — trk1836.html
Geology and geophysics 
Multi-beam echosoundingQuantity: track kilometres = 796
Single channel seismic reflectionQuantity: track kilometres = 796
Seismic refractionQuantity: number of track lines = 4
Description: Each approximately 19km
Magnetic measurementsQuantity: track kilometres = 796