A new (aeolian) perspective of coral island formation in the Maldives
Free Public Lecture
221 Bouverie Street, Theatre 2
221 Bouverie Street
T: 8344 9395
The islands of the Maldives are rim or lagoon islands associated with coral atolls. They are generally known as some of the lowest-lying areas of land on the planet and vulnerable to eustatic sea-level rise associated with climate change. Geomorphologists have assumed islands form as a result of wave transformation across reef platforms; but the question remains - how do lagoon islands emerge? Surprizingly, it appears that aeolian sedimentation – the transport of sand by wind – plays an important role. This seminar reports the results of a series of aeolian experiments on one lagoon island – Maaodegalaa – in Huvadhoo Atoll. Incident and near-surface wind speed and direction were recorded on the island at 1Hz for 8 days during a second visit in February 2018. Two major sand transport events, recorded using Wenglor laser particle counters and sand traps, occurred on the island during this period. The effect of these winds across the surface of the island was to transport sand towards the core of the island, a process that was enhanced by topographic acceleration over beach scarps cut during spring high tides. Onshore winds are clearly capable of transporting sand and contributing to island accretion, but the complex stratigraphy of the islands suggests over-wash processes are also important.
Associate Professor Michael Hilton, University of Otago
Associate Professor Michael Hilton
University of Otago
Mike is a geographer and a coastal geomorphologist in the Department of Geography at the University of Otago, New Zealand. His research primarily concerns processes of sedimentation on temperate sandy coasts, with particular interests in the measurement of wind and sand transport, beachforedune processes, the development of transgressive dune systems, and the restoration of dune systems invaded by exotic grasses. He has related interests in ecosystem assessment for conservation, environmental monitoring and storm surge. He works closely with management agencies in New Zealand and Australia to promote the conservation of dune systems. Mike is Secretary of the International Society of Aeolian Research and past executive member of the New Zealand Coastal Society and the New Zealand Geographical Society.