Cruise inventory

RRS John Murray JM4/79

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS John Murray (74MJ)
Cruise identifierJM4/79
Cruise period1979-04-03 — 1979-04-26
Port of departureBarry, United Kingdom
Port of returnBarry, United Kingdom
Objectives1) To clarify aspects of the near surface geography in the St George's Channel, Cardigan and Caernarvon bays arising out of previous research cruises.

2) To compare and contrast the performance of various seismic profiling equipment over known geological sequences in Cardigan Bay with the intention of establishing a series of test lines for the evaluation of seismic profiling equiptment

3) To carry out a calibration of the newly aquired La Coste Gravimeter over the Blackstones Bank gravity range, to the S.W. of Mull

4) To establish a grid of Gravity, Magnetic and Air-gun seismic profiling traverses across the Hebrides Terrace Seamount and to sample the Seamount using a rock dredge.
Chief scientistR J Whittington (University of Wales Aberystwyth Department of Geology)
Cruise reportRRS John Murray JM4/79 cruise report john_murray4_79.pdf — access key 'C' (0.11 MB) 
Ocean/sea areas 
GeneralIrish Sea and St. George's Channel
North East Atlantic Ocean (limit 40W)
Geology and geophysics 
DredgeQuantity: number of deployments = 6
Core - rockQuantity: number of cores = 4
Single channel seismic reflectionQuantity: track kilometres = 2222.4
Gravity measurementsQuantity: track kilometres = 1481.6
Magnetic measurementsQuantity: track kilometres = 1481.6
Description: format: 0 means analogue trace.