RRS James Clark Ross JR20120207 (JR255B, JR259, JR275)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20120207 (JR255B, JR259, JR275)
Cruise period2012-02-07 — 2012-03-22
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
ObjectivesThe cruise took place from 7th February 2012 to 22nd March 2012. It was a BAS National Capability cruise for the Geological Long Term Monitoring and Survey (LTMS) Work package.

It was joined with cruise JR275 (Evolutionary History Workpackage), specifically benthic biology, which belonged to the same BAS Science Programme (Environmental Change and Evolution). The main objectives of JR259 and JR275 were closely integrated. It was also joined with JR255B (retrieval of oceanographic gliders from the south Drake Passage and South Orkney area) a logistics visit to Halley and a logistic visit to Signy.

Five days were lost at the start of the cruise due to late arrival of the ship in the Falklands and engineering works. Small surveys and dredging in the West Scotia Ridge and Herdman Bank and the passage to the South Sandwich Islands were successful and completed in good time. Work in the South Sandwich arc was abandoned because of bad weather and shortage of time. Work in the Weddell Sea was mainly for cruise JR275, and consisted of benthic biology sampling on the Weddell Sea continental margin and continental slope using Agassiz trawls and an Epibenthic Sledge fitted with a camera. This sampling was very successful. During this time, JR259 provided swath bathymetry coverage of sites to be sampled by the biologists, and to provide data and assessments of suitability of sites. This combination was very effective at identifying good sites for the biology sampling. A swath bathymetry survey of the continental slope from the shelf brake to locally over 2000 m was completed for the eastern Weddell Sea, as far as ice conditions and time would allow.

After personnel uplift from Halley, and transect of the Weddell Sea, retrieval of oceanographic gliders for JR255B was attempted. This was partially successful, in that one of three gliders deployed was retrieved. Two gliders were not retrieved because their GPS location systems failed. A short swath survey of the South Scotia ridge was carried out before transit to Signy.
Chief scientistPhil T Leat (British Antarctic Survey)
ProjectEnvironmental Change and Evolution Programme (BAS)
Coordinating bodyNatural Environment Research Council (NERC)
Cruise reportRRS James Clark Ross JR20120207 (JR255B, JR259, JR275) cruise report jr259.pdf (2.56 MB)  RRS James Clark Ross JR20120207 (JR255B, JR259, JR275) cruise report jr275.pdf (1.75 MB) 
Ocean/sea areas 
GeneralSouthern Ocean
SpecificWest Scotia Ridge, Herdman Bank, Continental slope, Eastern Weddell Sea, South Scotia Ridge
Track chartsRRS James Clark Ross JR20120207 (JR255B, JR259, JR275) cruise track — jr259trk.pdf (0.52 MB) 
Physical oceanography 
BathythermographQuantity: number of deployments = 12
Description: XBT bathythermograph deployments to obtain water temperature with depth profiles for callibrating multi-beam echosounder bathymetric data
CTD stationsQuantity: number of profiles = 22
Description: CTD casts
CTD stationsQuantity: number of profiles = 15
Description: CTD casts with water samples from Niskin bottles
Current profiler (eg ADCP)Quantity: number of profiles = 22
Description: LADCP
Other physical oceanographic measurementsQuantity: number of recoveries = 1
Description: Glider recovery
Biology and fisheries 
PhytobenthosQuantity: number of deployments = 18
Description: Epibenthic Sledge
ZoobenthosQuantity: number of deployments = 18
Description: Epibenthic Sledge
Exploratory fishingQuantity: number of hauls = 56
Description: Agassiz trawl
Geology and geophysics 
DredgeQuantity: number of hauls = 3
Description: Dredges of sea floor rock outcrops of volcanic a granitic rock for geochronology and geochemical analysis to contribute to knowledge of tectonic evolution of Scotia Sea.
Core - soft bottomQuantity: number of cores = 1
Description: Sub core of soft sediment from sea floor on continental shelf in Weddell Sea. 0.13 m length of core from 675 m water depth.
Multi-beam echosoundingQuantity: activity duration in days = 38
Description: Multi-beam echosounder bathymetric data. Hull-mounted EM122 system. Continuous recording except when ship stopped, passing over previous data, or in bad weather.
Other geological/geophysical measurementsQuantity: activity duration in days = .5
Description: Sub-bottom profiler data using TOPAS hull-mounted system. Discrete surveys around benthic biological trawl sites sampled on JR275.
Data held at BODC Get data
Discrete samples 
1  Box core
22  CTD frame plus rosette sampler
74  Epibenthic Sledge
13  Expendable Bathythermograph