Coupling leeside grainfall to avalanche characteristics in aeolian dune dynamics
Coupling leeside grainfall to avalanche characteristics in aeolian dune dynamics
Avalanche (grainflow) processes are fundamental drivers of dune morphodynamics and are typically initiated by grainfall accumulations. In sedimentary systems, however, the dynamism between grainfall and grainflow remains unspecified because simple measurements are hampered by the inherent instability of lee slopes. Here, for the first time, terrestrial laser scanning is used to quantify key aspects of the grainfall process on the lee (slip face) of a barchan sand dune. We determine grainfall zone extent and flux and show their variability under differing wind speeds. The increase in the downwind distance from the brink of peak grainfall under stronger winds provides a mechanism that explains the competence of large avalanches to descend the entire lee slope. These findings highlight important interactions between wind speed, grainfall, and subsequent grainflow that influence dune migration rates and are important for correct interpretation of dune stratigraphy.
271-274
Nield, Joanna M.
173be2c5-b953-481a-abc4-c095e5e4b790
Wiggs, Giles F.S.
0b574ec8-fcd5-43b8-8b0b-0c84a01499d4
Baddock, Matthew C.
55f062fc-50a1-4c2d-83ff-a8cc92562346
Hipondoka, Martin H.T.
72b4ae3c-12d4-492b-a89d-232478c4f868
9 January 2017
Nield, Joanna M.
173be2c5-b953-481a-abc4-c095e5e4b790
Wiggs, Giles F.S.
0b574ec8-fcd5-43b8-8b0b-0c84a01499d4
Baddock, Matthew C.
55f062fc-50a1-4c2d-83ff-a8cc92562346
Hipondoka, Martin H.T.
72b4ae3c-12d4-492b-a89d-232478c4f868
Nield, Joanna M., Wiggs, Giles F.S., Baddock, Matthew C. and Hipondoka, Martin H.T.
(2017)
Coupling leeside grainfall to avalanche characteristics in aeolian dune dynamics.
Geology, 45 (3), .
(doi:10.1130/G38800.1).
Abstract
Avalanche (grainflow) processes are fundamental drivers of dune morphodynamics and are typically initiated by grainfall accumulations. In sedimentary systems, however, the dynamism between grainfall and grainflow remains unspecified because simple measurements are hampered by the inherent instability of lee slopes. Here, for the first time, terrestrial laser scanning is used to quantify key aspects of the grainfall process on the lee (slip face) of a barchan sand dune. We determine grainfall zone extent and flux and show their variability under differing wind speeds. The increase in the downwind distance from the brink of peak grainfall under stronger winds provides a mechanism that explains the competence of large avalanches to descend the entire lee slope. These findings highlight important interactions between wind speed, grainfall, and subsequent grainflow that influence dune migration rates and are important for correct interpretation of dune stratigraphy.
Text
Nield_etal_Geology2016_accepted_doi_10_1130_G38800_1.pdf
- Accepted Manuscript
Text
Geology-2017-Nield-G38800.1.pdf
- Version of Record
Available under License Other.
More information
Accepted/In Press date: 1 December 2016
e-pub ahead of print date: 9 January 2017
Published date: 9 January 2017
Organisations:
Earth Surface Dynamics
Identifiers
Local EPrints ID: 404500
URI: http://eprints.soton.ac.uk/id/eprint/404500
ISSN: 0091-7613
PURE UUID: 2ff0eca8-bed3-46cb-b978-f5a662c194c4
Catalogue record
Date deposited: 10 Jan 2017 10:00
Last modified: 16 Mar 2024 03:56
Export record
Altmetrics
Contributors
Author:
Giles F.S. Wiggs
Author:
Matthew C. Baddock
Author:
Martin H.T. Hipondoka
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
