Imperial College London
Portrait Picture

Prof Jenny Collier

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Marine Geophysics
 
 
 
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Contact

 

+44 (0)20 7594 6443jenny.collier CV

 
 
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Location

 

4.46Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Arosio:2021:10.1016/j.geomorph.2021.107692,
author = {Arosio, R and Collier, JS and Hawes, J and Gupta, S and Sperry, J},
doi = {10.1016/j.geomorph.2021.107692},
journal = {Geomorphology},
pages = {1--15},
title = {New perspectives on the English Channel megaflood hypothesis: High-resolution multibeam and seabed camera imaging of submarine landforms in the Northern Palaeovalley},
url = {http://dx.doi.org/10.1016/j.geomorph.2021.107692},
volume = {382},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A network of large, bedrock-incised valleys is preserved on the seabed of the English Channel. Based on analysis of a 30×30 m bathymetric grid, the morphology of the valleys was interpreted to be a consequence of erosion by catastrophic flood processes from overspill of a large proglacial lake in the Southern North Sea. The significance of the “megaflood features” has since been recognized by the UK Government with the designation of their protected status in one of three Marine Protected Areas (MPAs) within the palaeovalley in the central English Channel. Here, we analyse recent multibeam bathymetry data (2×2 m DEM) from these MPAs, together with backscatter and high-definition seabed camera imagery. The new data allow us to ground truth and refine the earlier interpretation and recognize previously undiscovered finer features. Streamlined valley margins, streamlined islands and metres-deep scours eroded into the valley floor are described at higher detail, while new subtle features on the valley floor such as kilometre-long, sub-parallel inner channels and streamlined bedrock ridges are identified for the first time. These features are consistent with a high energy erosion origin. We also identify isolated large boulders (>1m length) on flat seabed on the flanks of the palaeovalley, which are consistent with deposition from megaflood processes, although wave action during transgression/regression cannot be ruled out. Our new results enable more robust morphological evidence to support the influence of catastrophic flooding on bedrock valley incision in the English Channel.
AU  - Arosio,R
AU  - Collier,JS
AU  - Hawes,J
AU  - Gupta,S
AU  - Sperry,J
DO  - 10.1016/j.geomorph.2021.107692
EP  - 15
PY  - 2021///
SN  - 0169-555X
SP  - 1
TI  - New perspectives on the English Channel megaflood hypothesis: High-resolution multibeam and seabed camera imaging of submarine landforms in the Northern Palaeovalley
T2  - Geomorphology
UR  - http://dx.doi.org/10.1016/j.geomorph.2021.107692
UR  - https://www.sciencedirect.com/science/article/pii/S0169555X21001008?via%3Dihub
UR  - http://hdl.handle.net/10044/1/88086
VL  - 382
ER  -
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