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EARTH SCIENCE > Paleoclimate > Ocean/Lake Records > Sediments

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From 1 - 6 / 6
  • Sediment trap and delta samples were taken from Moutonnee Lake on Alexander Island during the 2001-2002 field season. Samples were analysed for grain size, Carbon and Nitrogen content and isotopic Carbon content. Delta samples were also analysed for luminescence dating.

  • The dataset contains chronological and biomarker compound and brGDGT (branched Glyceryl Dialkyl Glyceryl Tetraether) mean summer temperature (MSAT) data for the last c. 6,000 years from sediments extracted from Fan Lake on Annenkov Island (near South Georgia) and Yanou Lake, King George Island, South Shetland Islands. Temperature was reconstructed using the Pearson et al. (2011) global calibration and the Foster et al. (2016) Antarctic calibration. For the latter, we studied 32 lakes from Antarctica, the sub-Antarctic Islands and Southern Chile to: 1) quantify their GDGT composition and investigate the environmental controls on GDGT composition; and 2) develop a GDGT-temperature calibration model for inferring past temperatures from Antarctic and sub-Antarctic lakes. The downcore temperature reconstruction data produced using the new Antarctic brGDGT-temperature calibration were tested on Fan Lake and Yanou Lake to provide a proof of concept for the new calibration model in the Southern Hemisphere. This study is an output of the British Antarctic Survey (BAS) Natural Environment Research Council (NERC) funded Science Program, and was funded by NERC Studentship NE/J500173/1 to LF (BAS and Newcastle University) with additional support from: the European Commission under the 7th Framework Programme through the Action - IMCONet (FP7 IRSES, action No.319718 and the ESF-funded IMCOAST project AP6 to SJR, both coordinated by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Germany). Additional funding from the Natural Environmental Research Council (NERC-CASS), and the German Research Foundation (DFG project no. BR 775/25-1). Logistic support from the NERC-British Antarctic Survey (BAS), HMS Endurance and 892 Naval Air Squadron, the Alfred Wegner Institute (AWI) and the Instituto Antartico Argentino (IAA).

  • Ice sheet model runs based on the Glimmer thermo-mechanical ice sheet model. Glacial modelling was used to simulate former WAIS (West Antarctic Ice Sheet) dynamics (specifically grounding line and ice volume changes) in the Weddell Sea embayment, constrained by newly acquired field data (see related datasets).

  • Sediment cores were collected from the 3 sites (approx. 6m from Moutonnee Valley, 2.5m from Ablation Valley and 5m from Citadel Bastion on Alexander Island). They were analysed for physical property data including: magnetic susceptibility, wet weight, loss on ignition, grain size, isotopic content, bulk carbon, CHN, diatom content, forams, Authigenic carbonate, radiocarbon ages, Strontium and Neodymium content, major, trace and rare earth elements of sediments and clasts and clast lithological analysis. Analyses were carried out at Durham and Edinburgh with isotopic analysis conducted at NIGL (NERC Isotopic Geoscience Laboratory).

  • A transect of cores was taken from shelf to deep sea west of the Antarctic Peninsula off Marguerite Bay using a 12 m RVS piston corer, box corer and BGS vibrocorer deployed from RSS James Clark Ross cruise JR71 (12 days sea-time in 2001-2002). Successful coring and examination of sediments now on and immediately beneath the sea floor, which provided the deforming bed of the former ice stream, enhanced our understanding of conditions beneath ice streams. 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.

  • Sediments cores collected 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.