Science during the 2008 Disko Bay Expedition

The research undertaken during the 2008 expedition will build on the important scientific and artistic research begun in 2007. In 2008, scientists from the National Oceanography Centre and the British Geological Survey will focus on the West coast of Greenland to further explore the continuing northern ice melt. Dr Simon Boxall will measure the ocean tract across the Labrador Current (for direct comparison with the 160 mile ocean tract measured in 2007).  Dr Carol Cotterill will carry out extensive sequence stratigraphy analysis, see below for more details on this research proposal.

Research Proposal from the British Geological Survey 

In September 2008 the British Geological Survey, working with Cape Farewell, plan to extend their scientific investigations of climate change in the Arctic below the seabed. Sequence stratigraphy is the anaylsis of sediment deposition in the past, and the architecture it forms. It can give insights into past climates, changes in sea-level and the speed over which any changes occurred.

When sea-level rises, it creates “accommodation space” on the continental shelves – increasing the area between the seafloor and the sea surface in which sediments can be laid down. Sediment deposition then tends to become concentrated in proximity to the coast, building sediment packages preferentially upwards instead of extending outwards. As sea-level falls, accommodation space is reduced, forcing sediment deposition to go seawards, following the changing coastline as new land emerges. Both these scenarios leave specific sediment architectures that can give an indication of past climate change cycles.

These sub-surface cross sectional images are obtained using seismics – different frequencies of sound that penetrate the seabed and rebound off layers within the sediments below. Where a sediment package changes in orientation – say from horizontal to slightly dipping, or in grain size, the sound signal will re-bound back to a receiver that is towed at the sea surface.

It is known that during the deglaciation and ice sheet retreat that occurred approximately 120,000 ago, the seas around Greenland were about 2 degrees Celsius higher than at present. If we can image and interpret the sediment packages deposited during this major fluctuation in climate, and attempt to gauge the timescale over which it occurred from radiocarbon dating of sediment cores, we may be able to more accurately model the impacts of the current climate changes on the Arctic and north-west European environment.

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