RRS James Clark Ross JR20020212 (JR71)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20020212 (JR71)
Cruise period2002-02-12 — 2002-03-19
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
ObjectivesCruise JR71 had four main objectives:
1) Survey and coring on the continental shelf and slope east of the northern Antarctic
Peninsula, within and offshore from the areas formerly covered by the ice shelves in Prince
Gustav Channel, Larsen-A and Larsen-B (SAGES core programme, led by Dr C J Pudsey)
2) Survey and coring on the continental shelf and slope offshore Marguerite Bay (AFI
project 48/02, led by Prof J A Dowdeswell)
3) Surface water sampling for diatom assemblages (AFI-CGI project 99/02, led by Dr J
4) A CTD transect across the northern limb of the Weddell Gyre, to measure the outflow of
Weddell Sea Bottom Water (opportunistic project led by Dr K Nicholls).
Underway measurements included swath bathymetric, TOPAS and magnetic survey,
plus the routine collection of ocean-logger and acoustic doppler current profiler data.
The cruise occupied 34.5 days (Feb 12th to March 19th, Stanley to Stanley) plus three
days of mobilisation and one day of demobilisation. The weather was generally very good and no time was spent hove-to, though it was often necessary to slow down because of ice conditions combined with poor visibility. A small amount of time was lost on account of equipment failure (the BGS vibrocorer and the ship's Seametrix system). 21 hours were spent on passage to/from Rothera and alongside transferring passengers and cargo.
Chief scientistCarol J Pudsey (British Antarctic Survey)
ProjectSignals in Antarctica of Global Changes (SAGES)
Coordinating bodyBAS
Cruise reportRRS James Clark Ross JR20020212 (JR71) cruise report jr71.pdf (10.21 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
South Pacific Ocean
SpecificMarguerite Bay &Larsen Ice Shelf
Track chartsRRS James Clark Ross JR20020212 (JR71) cruise track — jr71track.pdf (14.03 MB) 
Physical oceanography 
BathythermographDescription: XBT's were deployed throughout the cruise. No. of deployments not noted.
Geology and geophysics 
Core - soft bottomDescription: The magnetometer was deployed and numerous cores were also taken. No. of deployments not noted.
Core - soft bottomDescription: In Prince Gustav Channel box core samples were taken in vibrocore sites, in order to get a sample without disurbed sediment. No. of samples not noted.
Single channel seismic reflectionQuantity: number of deployments = 1
Description: Just south of the Shackleton Fracture Zone the TOPAS sub-bottom profiler was deployed.
Magnetic measurementsDescription: The magnetometer was deployed and numerous cores were also taken. No. of deployments not noted.