RRS James Clark Ross JR20040123 (JR104)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20040123 (JR104)
Cruise period2004-01-23 — 2004-02-13
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnStanley, Falkland Islands (Malvinas)
ObjectivesThe data and samples collected on cruises JR104 will form the main basis for a study of glacial-interglacial changes in the southern Bellinghausen Sea. Reconnaissance data collected on previous cruises suggesterd that this area contained the outlet of a very large ice drainage basing during the late Quarternary glacial periods. The data were used as the basis for an Antarctic Funding Initiative (AFI) proposal to carry out the first systematic investigation of the former ice drainage basin. The ship time for JR104 was allocated to support the resulting project (AFI4/17).

The scientific questions set out in the AFI proposal were:
1. What was the extent of the ice drainage basin, and what sub-glacial processes operate on the shelf?
2. When, and how rapidly, did ice retreat from the continental shelf?
3. What processes control the development and stability of Antarctic trough-mouth fans?

On crusies JR104 these questions were addressed by collecting swath bathymetry (EM120) data, acoustic sub-bottom profiler (TOPAS) data, and sediment cores from selected areas on the continental shelf and slope. The programme of data collection was very successful, despite the fact that parts of the area investigated were still covered by first year sea ice. Although the limits on ship times that can be allocated through AFI were a tight constraint, unsually good weather resulted in no downtime due to adverse conditions, and the data and samples collected should be sufficient to achieve the main objectives of the project.
Chief scientistRobert D Larter (British Antarctic Survey)
Cruise reportRRS James Clark Ross JR20040123 (JR104) cruise report jr104.pdf (4.05 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
SpecificBellinghausen Sea
Geology and geophysics 
Core - soft bottomDescription: A number of cores were made throughout the group. No. of cores not noted.
Multi-beam echosoundingDescription: A number of multi-beam echo sounder profiles took place. No. of profiles not noted.
Single channel seismic reflectionDescription: A number of TOPAS surveys were made throughout the cruise. No. of surveys not noted.
Magnetic measurementsDescription: A magnetometer survey took place during the cruise. No. of profiles not noted.