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Emery, AR orcid.org/0000-0003-1231-0148, Hodgson, DM, Barlow, NLM et al. (5 more authors) Ice sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North Sea. Earth Surface Dynamics (ESurf). ISSN 2196-6311 (Submitted)
Abstract
Submerged landscapes on continental shelves archive drainage networks formed during periods of sea-level lowstand. The evolution of these postglacial drainage networks also reveals how past climate changes affected the landscape. Ice-marginal and paraglacial drainage networks on low-relief topography are susceptible to reorganisation of water supply, forced by ice-marginal rearrangement, precipitation and temperature variations, and marine inundation. A rare geological archive of climate-driven landscape evolution during the transition from ice-marginal (c. 23 ka BP) to a fully submerged marine environment (c. 8 ka BP) is preserved at Dogger Bank, in the southern North Sea.
In this study, our analysis of high-resolution seismic reflection and Cone Penetration Test data reveal a channel network over a 1330 km2 area that incised glacial and proglacial lake-fill sediments. The channel network sits below coastal and shallow marine sediments, and is therefore interpreted to represent terrestrial drainage network. When mapped out, the channel form morphology reveals two distinct sets. The first set comprise two low sinuosity, wide (> 400 m) channels that contain macroforms of braid and side bars. These channels are interpreted to have originated as proglacial rivers, which drained the ice-sheet margin to the north. The second set of channels (75–200 m wide, with one larger, ~ 400 m wide) have higher sinuosity and form a sub-dendritic network of tributaries to the proglacial channels.
The timing of channel formation lacks chronostratigraphic control. However, the proglacial rivers must have formed as the ice sheet was still on Dogger Bank, before 23 ka BP, to supply meltwater to the rivers. Ice-sheet retreat from Dogger Bank led to reorganisation of meltwater drainage and abandonment of the proglacial rivers. Palaeoclimate simulations show a cold and dry period at Dogger Bank between 23 and 17 ka BP. After 17 ka BP, precipitation increased, and drainage of precipitation formed the second set of channels. The second set of rivers remained active until marine transgression of Dogger Bank at c. 8 ka BP. Overall, this study provides a detailed insight into the evolution of river networks across Dogger Bank, and highlights the interplay between external (climate) and internal (local) forcings in drainage network evolution.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Geography (Leeds) > River Basin Processes & Management (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 13 Aug 2020 11:33 |
Last Modified: | 13 Aug 2020 11:33 |
Status: | Submitted |
Publisher: | European Geosciences Union |
Identification Number: | 10.5194/esurf-2020-41 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:164254 |
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Ice sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North Sea. (deposited 13 Aug 2020 11:33)
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- Ice sheet and palaeoclimate controls on drainage network evolution: an example from Dogger Bank, North Sea. (deposited 01 Oct 2020 13:50)