Echo-sounding data collected using the hull-mounted Simrad EK500 aboard the James Clark Ross (cruise no JR58) in 2001. This formed part of a project to determine the structure of zooplankton aggregations through multi-frequency acoustics and nets. The echo-sounder was used during net hauls where the net-mounted TUBA, multi-frequency acoustic system, was deployed, and was used to identify suitable targets of zooplankton layers or swarms.
This dataset relates to geophysical marine data collected onboard the RRS James Clark Ross (JR71) during 2002, which built on swath bathymetry and TOPAS survey undertaken on the JR59 cruise in 2001. Data was collected using Kongsberg-Simrad EM120 multibeam swath bathymetry and a TOPAS sub-bottom profiler. Data was collected as part of a project was to reconstruct the Late Quaternary dynamics of the Antarctic Peninsula Ice Sheet in Marguerite Bay and to compare sedimentation and ice-rafted debris records with the Larsen Ice Shelf area, on the other side of the Antarctic Peninsula. The mapping of streamlined sedimentary bedforms on the outer shelf has allowed the dimensions of a former fast-flowing ice stream present at the Last Glacial Maximum to be defined. This, in turn, enabled estimates of the past magnitude of ice flow through this glacial system to be calculated.
Swath bathymetry data were collected using a EM120 multibeam echo sounder and the TOPAS sub-bottom profiling system aboard the RRS James Clark Ross (JR104) in the Bellingshausen Sea, 2004. This work was carried out as part of the first systematic investigation of the former ice drainage basin in the southern Bellingshausen Sea. Reconnaissance data collected on previous cruises JR04 (1993) and cruises of R/V Polarstern in 1994 and 1995 suggested that this area contained the outlet of a very large ice drainage basin during late Quaternary glacial periods. The data and samples collected allowed us to address questions about the timing and rate of grounding line retreat from the continental shelf, the dynamic character of the ice that covered the shelf, and its influence on glaciomarine processes on the adjacent continental slope.