Abstract: Tropical cyclones generate extreme hazards along coastlines, often leading to losses of life and property. Although coral reefs exist in cyclone-prone regions globally, few studies have measured the hydrodynamic conditions and morphological responses of reef-fringed coastlines to tropical cyclones. Here, we examine the impact of Tropical Cyclone Olwyn on a section of Australia’s largest fringing reef (Ningaloo Reef) using in situ wave and water level observations, topographic surveys, and numerical modeling. Despite forereef significant wave heights reaching 6 m and local winds of 140 km h-1, average beach volume change was only -3 m3 m-1. The results indicate that this erosion was due to locally generated wind waves within the lagoon rather than the offshore waves that were dissipated on the reef crest. A comparison of these volume changes to observations of tropical cyclone impacts along exposed sandy beaches quantitatively demonstrates the substantial coastal protection reefs can provide against extreme storms.
Authors: Cuttler, M. V., J.E. Hansen, R.J. Lowe, and E.J. Drost
Limnology and Oceanography Letters 3(2). https://doi.org/10.1002/lol2.10067