GLANAM ITN (2013-2017)
The Glaciated North Atlantic Margins (GLANAM) ITN ended 31. March 2017. One output of the ITN has been a film showing some of the key results.
The Glaciated North Atlantic Margins (GLANAM) ITN (www.glanam.org) ended 31. March 2017. One of the output of the project has been a film (www.glanam.org/film/) explaining the importance of the ITN and some of its key results.
The ITN have comprised eight full partners and two associated partners from Norway, UK and Denmark. Three of the partners were private enterprises, the rest were governmental institutions and universities. The scientific goal of the GLANAM ITN has been to determine the controls on the development, in time and space, of glaciated continental margins. To reach this goal the GLANAM ITN focused on the North Atlantic continental margins from Ireland in the south to Greenland and Svalbard in the north, and 15 fellows (4 ERs and 11 ESRs), 8 male and 7 females, from 10 different European countries have been connected to the network.Over 30 papers in international peer-reviewed journals are either published or in process, and more are being developed by the team. A notable project output will be a Special Issue of the journal Marine Geology on Glaciated North Atlantic Margins. The network has also undertaken a wide range of outreach activities, including school visits and articles in public magazines.To achieve the goals described in the individual ITN subprojects the GLANAM fellows have analysed a wide range of geological and geophysical datasets including acoustic data as well as sediment cores. In addition, numerical modelling experiments of different types have been carried out. These achievements have contributed strongly to new knowledge on glaciated margins and the themes of the three ITN work packages:
WP1: Ice sheet history on circum-North Atlantic continental shelves. Four major ice sheets, the Greenland, British-Irish, Svalbard-Barents Sea and Fennoscandian ice sheets, delivered meltwater, icebergs and sediments into the North Atlantic during glacial periods, and seven of the GLANAM ITN subprojects have had a focus on ice sheet history and on determining the role of ice sheet advances and retreats in terms of spatial extent, flow dynamics and timing. The most important findings from WP1 are:
- The marine parts the British-Irish, Fennoscandian and Svalbard-Barents ice sheets are much more dynamic and unstable than previously documented, with a number of retreats/advances during the last glacial phase (from 30,000 to 10,000 years ago).
- A large number of absolute dates linked with ice marginal positions have led to new reconstructions of the last glacial phases of the studied ice sheets.
- New information of the pattern of retreat and retreat rates of large marine-based ice streams have been generated, showing that ice streams can retreat by speeds of up to 400 m/year.
WP2: Glacigenic sedimentation and sediment delivery across the continental margin from fjord to deep sea. Through four subprojects, this WP explored the link between sedimentary process and product and addressed the questions of how glacigenic sediments are formed at a local scale in both ice-proximal and ice-distal environments and how this relates to margin development. Important conclusions from WP2 are:
- Seismic data combined with ODP core data from the East Greenland margin reveals an asynchronous growth of the ice sheet across the shelf, with a marked northward shift of ice stream activity from the late Miocene to the present along the central East Greenland margin.
- On the West Greenland margin, investigations of two bank areas adjoining the Disko Trough demonstrate the influence of local factors, e.g. topography and tectonics, on ice dynamics.
- Investigation of acoustic data and sea bed samples from fjord systems with tide water glaciers on Greenland and Svalbard have produced new information of the sedimentary processes in these extreme environments.
WP3: The inter-relationship of glacial and non-glacial processes on the North Atlantic margins. Through four subprojects WP3 has focused on the question of how glacial processes interact with non-glacial processes across the North Atlantic margins and a range of different aspects pertaining to this problem, including modelling glacioisostatic adjustment and development of fluid flow systems on glaciated margins, have been conducted. Important conclusions from WP3 are:
- There is a detectable long-term influence of the ice loading history in the Barents Sea. This was tested through glacial isostatic adjustment modelling and compared to relative sea level data in order to infer the most likely former ice load scenario for this area. It was shown that, out of the four model ice load scenarios tested, only two provide a reliable fit to the observations.
- By combining observational data from the Barents Sea with numerical modelling, new information on major erosion episodes in the Mesozoic and Cenozoic have been obtained. These results are likely to have a significant impact on petroleum prospecting in the region.
- A compilation of post-glacial mass movements from 22 fjord systems and 6 lakes along the Norwegian coast strongly suggests that earthquakes, partly resulting from the last glacial rebound, are the most important trigger mechanism behind such events.
- Information on chronology and sediment characteristics from an area on the upper Norwegian continental slope, in combined with numerical modelling, suggest that sediment accumulation rates play an important role in the stability of gas hydrates.
The results of the GLANAM ITN have a wide societal relevance and impact towards national and local governments, private enterprises and to research groups at academic institutions in the following aspects: (i) Climate: the GLANAM ITN results are contributing towards a better understanding on how rapidly large, marine-based parts of an ice sheet can disintegrate. Such information is central to refine predictions of future sea level rise and to provide a better understanding on how freshwater input can influence oceanic circulation and climate; (ii) Geohazard: the GLANAM ITN has provided us with a better constraint on when, why and where mass failures events, which may have a devastating effect on population and infrastructure, can take place. Such information is important in order to predict where failure events may take place in the future; (iii) Hydrocarbon exploration, Carbon Capture Storage (CCS) and seabed installations: Modelling of the crustal movement resulting from repeated glaciations, as undertaken in the GLANAM ITN, is central for a better understanding of formation and migration of hydrocarbon and fluid flow systems on glaciated margins. Such information has also become important when evaluating areas for CCS. Improved knowledge of glacial sedimentary systems and processes in offshore areas are also important with respect to seabed infrastructure, e.g. offshore wind farms; and (iv) Energy: the GLANAM ITN has provided knowledge that is demonstrably central for understanding gas hydrate systems, a potential energy source, in glaciated regions