Effects of varied lithology on soft-cliff recession rates
Effects of varied lithology on soft-cliff recession rates
Geomorphic modelling is a key method to understand the soft cliff recession process to predict future rates of retreat and responses to climate change. A range of process-based models have been used; however the influence of varied vertical lithology has yet to be quantified. This paper describes modifications to the 2D SCAPE (Soft Cliff and Platform Erosion) model, carried out to explore such interactions between vertical changes in cliff resistive strength and prevailing coastal conditions. As expected, weaker (/more resistant) layers lead to more (/less) rapid retreat. However, this effect is strongly influenced by the position of such layers relative to mean sea level, where the erosive potential is greatest. Moreover, model simulations reveal that layers of variable resistance give an asymmetric response in terms of both rates of retreat and the timeframe for the effect to be realised. For example, a reduction of material strength of 1/5 (in comparison to the remainder of the cliff) about mean sea level results in a rapid 130% increase in the rate of retreat in comparison to the introduction of a five times more resistant layer of the same characteristics. This variation in response can be attributed to the different magnitudes of feedback governing profile reshaping associated with the change in lithology. For example, the introduction of a weaker layer amplifies erosion through its greater erosive potential combined with steepening of the overlying section. The results have important implications for the management of coastal cliffs exhibiting variable stratigraphy, combined with the potential for future interactions with sea-level rise.
40-52
Carpenter, N.
7e0413e1-5301-4039-8c20-b6631ded76fb
Dickson, M.E.
ddc83eac-255d-49f5-a17b-9fa56a214474
Walkden, M.J.A.
12dc72cf-904f-4d15-9448-49002a0bf5c3
Nicholls, R.J.
4ce1e355-cc5d-4702-8124-820932c57076
Powrie, W
600c3f02-00f8-4486-ae4b-b4fc8ec77c3c
1 August 2014
Carpenter, N.
7e0413e1-5301-4039-8c20-b6631ded76fb
Dickson, M.E.
ddc83eac-255d-49f5-a17b-9fa56a214474
Walkden, M.J.A.
12dc72cf-904f-4d15-9448-49002a0bf5c3
Nicholls, R.J.
4ce1e355-cc5d-4702-8124-820932c57076
Powrie, W
600c3f02-00f8-4486-ae4b-b4fc8ec77c3c
Carpenter, N., Dickson, M.E., Walkden, M.J.A., Nicholls, R.J. and Powrie, W
(2014)
Effects of varied lithology on soft-cliff recession rates.
Marine Geology, 354 (1), .
(doi:10.1016/j.margeo.2014.04.009).
Abstract
Geomorphic modelling is a key method to understand the soft cliff recession process to predict future rates of retreat and responses to climate change. A range of process-based models have been used; however the influence of varied vertical lithology has yet to be quantified. This paper describes modifications to the 2D SCAPE (Soft Cliff and Platform Erosion) model, carried out to explore such interactions between vertical changes in cliff resistive strength and prevailing coastal conditions. As expected, weaker (/more resistant) layers lead to more (/less) rapid retreat. However, this effect is strongly influenced by the position of such layers relative to mean sea level, where the erosive potential is greatest. Moreover, model simulations reveal that layers of variable resistance give an asymmetric response in terms of both rates of retreat and the timeframe for the effect to be realised. For example, a reduction of material strength of 1/5 (in comparison to the remainder of the cliff) about mean sea level results in a rapid 130% increase in the rate of retreat in comparison to the introduction of a five times more resistant layer of the same characteristics. This variation in response can be attributed to the different magnitudes of feedback governing profile reshaping associated with the change in lithology. For example, the introduction of a weaker layer amplifies erosion through its greater erosive potential combined with steepening of the overlying section. The results have important implications for the management of coastal cliffs exhibiting variable stratigraphy, combined with the potential for future interactions with sea-level rise.
This record has no associated files available for download.
More information
Published date: 1 August 2014
Organisations:
Faculty of Engineering and the Environment
Identifiers
Local EPrints ID: 365817
URI: http://eprints.soton.ac.uk/id/eprint/365817
ISSN: 0025-3227
PURE UUID: 454e8f9e-822d-4504-bce3-a2a9d9d19afe
Catalogue record
Date deposited: 17 Jun 2014 12:10
Last modified: 15 Mar 2024 03:18
Export record
Altmetrics
Contributors
Author:
N. Carpenter
Author:
M.E. Dickson
Author:
M.J.A. Walkden
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics