|European North Atlantic Margin: Quantification and Modelling of Large-scale Sedimentary Processes and Fluxes|
|| Institute |
Reference no: MAS3-CT95-0003
Period: June 1996 till September 1998
Thesaurus terms: Continental margins; Modelling; Offshore; Quaternary period; Sea ice; Sedimentation
Geographical terms: ANE, Belgium, Belgian Continental Shelf (BCS) [Marine Regions]; ANE, North Sea, Southern Bight [Marine Regions]
|The overall objectives of the ENAM 11 project are to quantify large-scale sedimentary processes and to assess their relation to the variability of oceanic and cryospheric processes. Even though large research efforts have been devoted to deciphering the sedimentary processes moulding the margins, the timing, causes and flow behaviour of these large-scale events are still largely unknown. Physical properties of sediments prone to sliding and slumping are also poorly known as are relationships between rapid changes in sedimentation, pore pressures or the destabilisation of gashydrates. These changes must be understood in order to generate reliable models for large-scale sedimentary processes, in particular mass wasting and deep-sea fan developments. Both mass wasting and deep-sea fan developments should be investigated in relation to the variability of oceanic and cryospheric processes to obtain and to determine the frequencies and possible relationships of individual events. Progress in resolving these major issues can only be achieved through the examination of high-resolution sedimentary records preserved in continental margin sediments. We therefore propose to quantify and model the sedimentary processes and material fluxes along sectors from the Norwegian (glaciated) Margin to the Celtic Sea (nonglaciated) Margin in transects running from the shelf edge to the continental slope and finally to the deep-sea. The designation of key geographic areas on the slope and the retrieval of appropriate samples are important for determining the high-resolution variability of the complex sedimentary system for Quaternary times. Areas of rapid sedimentation on the slope, which are sometimes prone to slope failure, enable evaluation of when and how rapidly ice sheet and associated hydrographic changes relate to adjacent continental slope instabilities and deep-sea fan build-ups. Although there is abundant evidence that significant natural variations in the ocean system have occurred on time scales of oceanic and cryospheric processes, the timing of large-scale sedimentary processes which may result from these variations are still largely unknown. Our primary objectives are therefore: (1)Quantification of large-scale sedimentary processes in Northeastern Atlantic Margin development and establishment of magnitudes of sediment fluxes from the shelf edge to the slope and deep-sea in glaciated and nonglaciated areas. (2)Determination of frequencies of mass wasting events and controls on the formation of deep-sea fans, and causes of instabilities including the wide range of physical and chemical processes contributing to the slope instability potential on margins.
(3) Determination of late Quaternary oceanographic conditions with a focus meltwater events governing the sediment fluxes and the relationship between cryospheric, oceanographic and sedimentary processes.
(4) Numerical modelling of rates of sediment delivery to the continental shelf edge by ice sheets and of the gravity mass wasting of this material on the continental slope.