RRS John Murray JM7/69

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM7/69
Cruise period1969-08-29 — 1969-09-22
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
ObjectivesCentrally to the cruise was a seismic experiment to determine crustal structure along lines westwards from the Pembrokeshire coast to the continental margin southwest of Ireland. The R.R.S. John Murray occupied sono-buoy recording stations and acted as communications centre to liase between other ships and stations.

Several minor experiments were scheduled:
a) collection of surface sea water samples at two stations
b) trials of oceanographic logging equipment
c) trials with a sono-buoy and sparker and an airgun to obtain wide angle reflections and refractions.
Chief scientistDerek J Blundell (University of Birmingham Department of Geology with Geophysics)
Cruise reportRRS John Murray JM7/69 cruise report john_murray7_69.pdf (0.40 MB) 
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
Celtic Sea
North East Atlantic Ocean (limit 40W)
SpecificSt George's Channel, Celtic Sea and Porcupine Seabight
Physical oceanography 
Water bottle stationsQuantity: number of stations = 2
Description: T surface only
Geology and geophysics 
In-situ seafloor measurement/samplingDescription: magnetometer
Seismic refractionDescription: sparker