Aeolian sedimentation (the transport of sand by wind) and dune development have not been reported from coral atolls at Equatorial latitudes. This study presents high-frequency measurements of near-surface wind flow and aeolian sand transport on a lagoon sand cay (Maaodegalaa) in the Maldives.
The measurements showed a range of wind-speed dependent transport processes, with the highest rates of sand transport occurring during short-duration wind bursts with strengths of about 12 m/s. These wind bursts were most likely generated by surface-based density currents (often called ‘cold pools’) formed by cumulonimbus clouds that were detected upwind of Maaodegalaa.
These processes make a significant contribution to island accretion and island development by providing habitat for early successional vegetation.
The study proposes a conceptual model of lagoon island formation, which incorporates aeolian sedimentation and episodes of wave and tide over-wash. Although not part of the core CLEX program, this study represents an interesting multi-disciplinary application of our work on tropical storms to geomorphology.
- Paper: M.J. Hilton, D.R. Borrie, T.M. Konlechner, S.J. Wakes, T.P. Lane, P.S. Kench, D.M. Kennedy, Mohamed Aslam. A first evaluation of the contribution of aeolian sand transport to lagoon island accretion in the Maldives, Aeolian Research, Volume 39, 2019, Pages 47-65, ISSN 1875-9637, https://doi.org/10.1016/j.aeolia.2019.04.006.