From 1 - 5 / 5
  • Categories  

    Revised full proposal for scientific drilling (852-CPP2) 'GlaciStore: Understanding Pleistocene glaciation and basin processes and their impact on fluid migration pathways (North Sea)', submitted to Integrated Ocean Discovery Programme (IODP) April 2016. The proponent 'GlaciStore' consortium comprises research and industry organisations from the UK, Norway, USA and Canada. The full proposal describes the relationship of the proposed research with the IODP science plan, sets the regional background and describes and illustrates three scientific objectives. The objectives are to: establish a high-resolution depositional and chronological framework defining multiple cycles of glacial advance and retreat over the last 2.6 Ma by investigating the strata preserved in the centre of the NSB by scientific drilling, sampling and detailed analysis; investigate how the temporal variations in depositional environment and geochemistry of the different stratigraphic units have affected the pore fluids (dissolved gases, salts and isotopes) and the microbial community; determine the measurable impact on geomechanical properties of strata (porosity, rock stiffness, in-situ stresses, pore pressure, fractures) caused by cycles of glacial loading and unloading. The drilling and sampling strategy, standard drilling and logging operations and the specialist measurements expected to be taken are described. Related initiatives and wider context of the proposed research also the initial and planned strategy for support from industry and government are outlined. The lead submitter, on behalf to the GlaciStore consortium is Heather Stewart, British Geological Survey (BGS).The 32 proponents from the UK and Norway (BGS, Institute for Energy Technology, Lundin Norway AS, Memorial University of Newfoundland, SINTEF Energy Research, Statoil ASA, University of Bergen, University of Edinburgh University of Oslo, University of Texas at Austin and University of Ottowa) and their expertise are listed and detailed. Site forms for each of the 13 proposed drilling sites are included.The full proposal is a pdf format file. This is restricted to the proponents for publication and to progress to a revised full proposal accepted for drilling by IODP. UKCCSRC Grant UKCCSRC-C1-30.

  • Categories  

    Numerical model predictions of present-day horizontal deformation due to ongoing glacial isostatic adjustment processes at GPS sites across Antarctica. Model accounts for 3D spatial variations in Earth rheology using a finite element approach.

  • Categories  

    Numerical model predictions of present-day solid Earth deformation and gravity field change due to ongoing glacial isostatic adjustment processes. Model accounts for 3D spatial variations in Earth rheology using a finite element approach.

  • Categories  

    Data generated using freely-available satellite remote sensing observations from the USGS Earth Resources Observation Science Centre, together with a freely-available ice margin chronology from Dyke et al. (2003) Geological Survey of Canada Open File Report No. 1574. The map is published in the Journal of Maps: http://www.tandfonline.com/doi/full/10.1080/17445647.2014.912036 Published article in 'Nature' Volume 530 Feb 2016 with associated source data. https://dx.doi.org/10.1038/nature16947 Published paper in the Taylor Francis Online Journal with associated data. https://dx.doi.org/10.1080/17445647.2014.912036

  • Categories  

    Antarctica and its ice sheets have played, and continue to play, a major role in the global ocean-atmosphere system, hence, it is critical that we have a sound understanding of the past behaviour of Antarctica and it's ice sheets with a view to understanding their potential future variability under a warming climate. The Southern Ocean is a key component of the thermohaline circulation of the world's oceans and the re-distribution of heat and salt around the oceans is integral to processes that regulate rapid climate transitions. Computer modelling results have shown that sufficient melt water input to the Antarctic continental shelf area is capable of shutting down the formation of cold, salty deep water in Antarctica hence upsetting the balance of the thermohaline circulation and the ocean-climate system of the Northern Hemisphere. In order to further investigate these processes that originate in Antarctica, it is necessary to understand the transfer mechanisms of ocean-climate signals from the Antarctic ice sheets, across the continental margin seas, into the Southern Ocean. Exceptionally well-preserved Antarctic margin sediment cores, recovered during the last decade, contain an excellent archive of these ice-ocean-climate interactions, often on seasonal timescales, from the end of the last ice age and throughout the recent warm interglacial (the Holocene). The cores are seasonally layered through the deglaication, intermittently layered through the Holocene, and the layers are dominated by fossil planktonic diatoms (algae); individual species of which are sensitive to sea surface conditions including sea ice concentration, fresh water influx, and open ocean influence upon the margin. Following the last ice age, these Holocene Antarctic sediments record climate fluctuations of tens to thousands of years long and whatever environmental forcing mechanism is responsible for these fluctuations, the changes are likely to be felt in the Antarctic coastal regions first, and the cores proposed for this research are located in prime positions to record these changes. Diatom oxygen isotope measurements represent an under-utilised technique that provides a means of obtaining oxygen isotope records in high latitude environments. The measurement of oxygen isotopes in diatoms is a widely used proxy in the study of the history of lakes, however, to date there have been many fewer attempts to use records of diatom oxygen isotopes in the oceans. Studies that have taken place have demonstrated the sensitivity of diatom oxyegn isotope measurements in polar and sub-polar waters to changes in surface ocean environmental parameters such as salinity, freshwater input and sea surface temperature. The research proposed here will be the first attempt to produce diatom oxygen isotope records from the Antarctic margin, a region sensitive to the waxing and waning of the Antarctic ice sheets in terms of melt water through-put to the Southern Ocean. We propose to investigate the evolution of seasonality along the Antarctic margin since the last ice age, and also the processes involved in producing the sediment record, by relating diatom oxygen isotope measurements on season-specific diatom taxa (i.e. diatom species that thrived particularly in spring or autumn) to relative freshwater influx to the coast, from either melted terrestrial ice or sea ice. We also hope to show that the diatom oxygen isotope measurements will be low at the end of the last ice age, as a large quantity of old ice sheets were melting, and will be higher during warmer time periods of the Holocene when ice sheets were at a minimum.