Cruise inventory

RRS James Clark Ross JR20150130 (JR298)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20150130 (JR298)
Cruise period2015-01-30 — 2015-03-04
StatusCompleted
Port of departurePunta Arenas, Chile
Port of returnPunta Arenas, Chile
PurposeResearch
ObjectivesThe main purpose of cruise JR298 was to collect marine geological and geophysical samples and data to support International Ocean Discovery Program (IODP) proposal 732-Full2, "Sediment drifts off the Antarctic Peninsula and West Antarctica" (Channell, Larter, Hillenbrand et al). The ship time was allocated for this purpose on the basis of a Site Survey Investigation grant from the NERC UK-IODP Programme (NE/J006548/1: Depositional patterns and records in sediment drifts off the Antarctic Peninsula and West Antarctica) to R.D. Larter, C.-D. Hillenbrand (both BAS), D.A. Hodell (University of Cambridge) and A.G.C. Graham (University of Exeter). The data and samples collected will also be used in two Collaborative Gearing Scheme projects, an Antarctic Science Bursary project, a University of Cambridge PhD studentship, and within the National Capability remit of the BAS Science Teams in "Geology and Geophysics" and "Palaeoenvironments and Climate Change".

These projects are:
- Tracing and reconstructing the neodymium and carbon isotopic composition of circum-Antarctic waters (CGS-100, PI: A.M. Piotrowski, Department of Earth Sciences, University of Cambridge; cruise participants: A.M. Piotrowski and T.J. Williams).
- Structural characterisation of Late Quaternary sediments from West Antarctic contourite drifts using three dimensional X-ray imaging (CT-scanning) (CGS-98, PI: C. Ó Cofaigh, Department of Geography, Durham University; cruise participant: J. Horrocks)
- Tracing the Quaternary evolution of the Antarctic Peninsula and West Antarctic Ice Sheets using lead isotopes in ice-rafted feldspar mineral grains (Antarctic Science Bursary awarded to C. Cook).
- Seismic imaging of oceanographic structures and processes in the Southern Ocean south of the Polar Front (component of University of Cambridge/BP Institute PhD studentship; primary supervisor: N.J. White, Department of Earth Sciences, University of Cambridge; PhD student and cruise participant: K.L. Gunn).
- Modelling crustal structure across the Bellingshausen Gravity Anomaly and oceanic fracture zones formed at the Antarctic-Phoenix Ridge through integration of marine potential field and seismic data (Collaboration between two BAS Science Teams; cruise participant: T.A.R.M. Jordan).

The cruise also provided support for physical oceanography projects by deploying six Argo floats and rescuing a malfunctioning sea glider.

Towards the end of the cruise, RRS James Clark Ross was diverted to Rothera to uplift 16 personnel who had been flown across from Halley in two ALCI Basler aircraft because the sea ice situation in the Weddell Sea was considered to pose a significant risk to the scheduled last call of the season at Halley by RRS Ernest Shackleton. This uplift resulted in a two-day delay to arrival at Punta Arenas at the end of the cruise, which was in addition to a two-day extension already agreed as a result of departure from Punta Arenas having been delayed by slow refuelling.

Adverse weather conditions, particularly during the first half of the cruise, resulted in more downtime than the amount of contingency time that had been allowed in the proposal. As a result, one less piston core and about 20% fewer line-km of seismic data were collected than had been planned. Nevertheless, the key objectives were achieved and the cores and data that were collected are of very good quality. The data and cores collected on cruise JR298, combined with existing data and cores, should satisfy all of the requirements of the Site Characterisation Panel and the Environmental Protection and Safety Panel of IODP. They will also provide a good basis for addressing the science objectives set out in the UK-IODP Site Survey Investigation proposal and those of the ancillary projects listed above.
Chief scientistRobert D Larter (British Antarctic Survey)
Coordinating bodyNatural Environment Research Council (NERC)
Cruise reportRRS James Clark Ross JR20150130 (JR298) cruise report jr298.pdf — access key 'C' (11.91 MB) 
Ocean/sea areas 
GeneralSouthern Ocean
SpecificSouthern Bellingshausen Sea. Pacific margin of the Antarctic Peninsula
Track chartsRRS James Clark Ross JR20150130 (JR298) cruise track — jr298trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 29
Description: BAS oceanlogger, temperature, conductivity
BathythermographQuantity: number of profiles = 11
Description: Expendable CTDs (XCTD-1 probes)
BathythermographQuantity: number of profiles = 23
Description: Expendable bathythermograph (19 x T5 probes and 4 x T7 probes)
CTD stationsQuantity: number of stations = 5
Description: Seabird SBE9plus CTD including fluorometer, oxygen sensor, PAR sensor, transmissometer, altimeter, LADCP and rosette of 24 x 12 l Niskin bottles
Current profiler (eg ADCP)Quantity: activity duration in days = 29
Description: RDI 75 kHz ADCP
Biology and fisheries 
Acoustic reflection on marine organisms.Quantity: activity duration in days = 23
Description: Kongsberg EK60, backscatter amplitude
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 29
Description: BAS oceanlogger, temperature, pressure, wind speed and direction
Geology and geophysics 
Core - soft bottomQuantity: number of stations = 8
Description: Box cores
Core - soft bottomQuantity: number of stations = 7
Description: Piston cores up to 13 m in length
Single-beam echosoundingQuantity: activity duration in days = 28
Description: Kongsberg EA600, water depth and reflection amplitude
Multi-beam echosoundingQuantity: activity duration in days = 28
Description: Kongsberg EM122, water depth, backscatter amplitude and some water column data
Multichannel seismic reflectionQuantity: track kilometres = 1960
Description: Multichannel seismic. Mostly using 2400 m (192 channel) streamer. Some lines acquired using 1200 m (96 channel) streamer. Source was 2 x 150 cu. in. GI guns firing in harmonic mode. Data recorded in SEGD format with 1 ms sampling interval.
Gravity measurementsQuantity: track kilometres = 5166
Description: Micro-g LaCoste Air-Sea System II gravity meter S/N S84
Magnetic measurementsQuantity: track kilometres = 3005
Description: SeaSpy Overhauser towed magnetometer
Other geological/geophysical measurementsQuantity: activity duration in days = 27
Description: TOPAS PS018 parametric sub-bottom profiler, reflection amplitude and travel time
Moorings, landers, buoys 
Physical oceanography 
Neutrally buoyant floats60° 30' 35" S  67° 16' 48" W — Argo float S/N 7019: temperature, salinity, depth, position
Neutrally buoyant floats58° 24' 24" S  66° 6' 11" W — Argo float S/N 5595: temperature, salinity, depth, position
Neutrally buoyant floats68° 56' 35" S  85° 47' 24" W — Argo float S/N 7020: temperature, salinity, depth, position
Neutrally buoyant floats61° 40' 29" S  67° 50' 48" W — Argo float S/N 7022: temperature, salinity, depth, position
Neutrally buoyant floats63° 26' 30" S  68° 51' 24" W — Argo float S/N 7021: temperature, salinity, depth, position
Neutrally buoyant floats59° 31' 0" S  66° 41' 41" W — Argo float S/N 7018: temperature, salinity, depth, position