‘Reshaping’ Charles Darwin’s classic theory on the formation of atolls

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A collaborative team of scientists from Thailand, Australia and Singapore, led by Professor James Terry of Zayed University in Dubai, is challenging existing ideas about the vulnerability of coastlines to certain types of natural hazards (tropical cyclones, submarine landslides and tsunamis) in the South China Sea, the Gulf of Thailand and the South Pacific islands.  Their research, published recently in several leading geoscience journals, including Earth-Science Reviews, Landslides, Earth Surface Processes & Landforms and Palaeogeography, Palaeoclimatology, Palaeoecology, has applied a combination of field-based measurements, mapping and modelling to suggest how some areas previously considered at relatively low risk are, in reality, exposed to such threats.  Sedimentary deposits discovered on some coastlines have provided age-datable evidence that yield clues illuminating the magnitude–timing–frequency of high-energy wave events during prehistorical times before modern records began.  One particular highlight of the work has been a contribution to ‘reshaping’ Charles Darwin’s classic theory on the formation of atolls.

Figure:  Stages in the morphological development of an atoll to include the role of submarine landslides, which are possibly tsunamigenic.  Flank landslides produce an irregular atoll shape with a scalloped outline.  Cycles of atoll flank collapse and reef regrowth may be repeated.