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Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields

Raked linear dunes keep a constant orientation for considerable distances with a marked asymmetry between a periodic pattern of semi-crescentic structures on one side and a continuous slope on the other. Here we show that this shape is associated with a steady-state dune type arising from the coexis...

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Autores principales: Lü, Ping, Narteau, Clément, Dong, Zhibao, Rozier, Olivier, Courrech du Pont, Sylvain
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290144/
https://www.ncbi.nlm.nih.gov/pubmed/28128195
http://dx.doi.org/10.1038/ncomms14239
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author Lü, Ping
Narteau, Clément
Dong, Zhibao
Rozier, Olivier
Courrech du Pont, Sylvain
author_facet Lü, Ping
Narteau, Clément
Dong, Zhibao
Rozier, Olivier
Courrech du Pont, Sylvain
author_sort Lü, Ping
collection PubMed
description Raked linear dunes keep a constant orientation for considerable distances with a marked asymmetry between a periodic pattern of semi-crescentic structures on one side and a continuous slope on the other. Here we show that this shape is associated with a steady-state dune type arising from the coexistence of two dune growth mechanisms. Primary ridges elongate in the direction of the resultant sand flux. Semi-crescentic structures result from the development of superimposed dunes growing perpendicularly to the maximum gross bedform-normal transport. In the particular case of raked linear dunes, these two mechanisms produces primary and secondary ridges with similar height but with different orientations, which are oblique to each other. The raked pattern develops preferentially on the leeward side of the primary ridges according to the direction of propagation of the superimposed bedforms. As shown by numerical modelling, raked linear dunes occur where both these oblique orientations and dynamics are met.
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spelling pubmed-52901442017-02-07 Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields Lü, Ping Narteau, Clément Dong, Zhibao Rozier, Olivier Courrech du Pont, Sylvain Nat Commun Article Raked linear dunes keep a constant orientation for considerable distances with a marked asymmetry between a periodic pattern of semi-crescentic structures on one side and a continuous slope on the other. Here we show that this shape is associated with a steady-state dune type arising from the coexistence of two dune growth mechanisms. Primary ridges elongate in the direction of the resultant sand flux. Semi-crescentic structures result from the development of superimposed dunes growing perpendicularly to the maximum gross bedform-normal transport. In the particular case of raked linear dunes, these two mechanisms produces primary and secondary ridges with similar height but with different orientations, which are oblique to each other. The raked pattern develops preferentially on the leeward side of the primary ridges according to the direction of propagation of the superimposed bedforms. As shown by numerical modelling, raked linear dunes occur where both these oblique orientations and dynamics are met. Nature Publishing Group 2017-01-27 /pmc/articles/PMC5290144/ /pubmed/28128195 http://dx.doi.org/10.1038/ncomms14239 Text en Copyright © 2017, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Lü, Ping
Narteau, Clément
Dong, Zhibao
Rozier, Olivier
Courrech du Pont, Sylvain
Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title_full Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title_fullStr Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title_full_unstemmed Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title_short Unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
title_sort unravelling raked linear dunes to explain the coexistence of bedforms in complex dunefields
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290144/
https://www.ncbi.nlm.nih.gov/pubmed/28128195
http://dx.doi.org/10.1038/ncomms14239
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