Imperial College London
Portrait Picture

Dr Alex Whittaker

Faculty of Engineering, Department of Earth Science & Engineering

Reader in Landscape Dynamics
 
 
 
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Contact

 

+44 (0)20 7594 7491a.whittaker Website

 
 
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Location

 

3.51Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Mitchell:2021:10.1111/bre.12460,
author = {Mitchell, WH and Whittaker, AC and Mayall, M and Lonergan, L and Pizzi, M},
doi = {10.1111/bre.12460},
journal = {Basin Research},
pages = {186--209},
title = {Quantifying the relationship between structural deformation and the morphology of submarine channels on the Niger Delta continental slope},
url = {http://dx.doi.org/10.1111/bre.12460},
volume = {33},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The processes and deposits of deepwater submarine channels are known to be influenced by a wide variety of controlling factors, both allocyclic and autocyclic. However, unlike their fluvial counterparts whose dynamics are wellstudied, the factors that control the longterm behaviour of submarine channels, particularly on slopes undergoing active deformation, remain poorly understood. We combine seismic techniques with concepts from landscape dynamics to investigate quantitatively how the growth of gravitationalcollapse structures at or near the seabed in the Niger Delta have influenced the morphology of submarine channels along their length from the shelf edge to their deepwater counterpart. From a three dimensional (3D), timemigrated seismicreflection volume, which extends over 120 km from the shelf edge to the base of slope, we mapped the presentday geomorphic expression of two submarine channels and active structures at the seabed, and created a Digital Elevation Model (DEM). A second geomorphic surface and DEM raster—interpreted to closer approximate the most recent active channel geometries—were created through removing the thickness of hemipelagic drape across the study area. The DEM rasters were used to extract the longitudinal profiles of channel systems with seabed expression, and we evaluate the evolution of channel widths, depths and slopes at fixed intervals downslope as the channels interact with growing structures. Results show that the channel long profiles have a relatively linear form with localized steepening associated with seabed structures. We demonstrate that channel morphologies and their constituent architectural elements are sensitive to active seafloor deformation, and we use the geomorphic data to infer a likely distribution of bed shear stresses and flow velocities from the shelf edge to deep water. Our results give new insights into the erosional dynamics of submarine channels, allow us to quantify the extent to which
AU  - Mitchell,WH
AU  - Whittaker,AC
AU  - Mayall,M
AU  - Lonergan,L
AU  - Pizzi,M
DO  - 10.1111/bre.12460
EP  - 209
PY  - 2021///
SN  - 0950-091X
SP  - 186
TI  - Quantifying the relationship between structural deformation and the morphology of submarine channels on the Niger Delta continental slope
T2  - Basin Research
UR  - http://dx.doi.org/10.1111/bre.12460
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000537713300001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://onlinelibrary.wiley.com/doi/full/10.1111/bre.12460
UR  - http://hdl.handle.net/10044/1/80081
VL  - 33
ER  -
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