Effects of cyclone-generated disturbance on a tropical reef foraminifera assemblage
نویسندگان
چکیده
The sedimentary record, and associated micropalaeontological proxies, is one tool that has been employed to quantify a region's tropical cyclone history. Doing so has largely relied on the identification of allochthonous deposits (sediments and microfossils), sourced from deeper water and entrained by tropical cyclone waves and currents, in a shallow-water or terrestrial setting. In this study, we examine microfossil assemblages before and after a known tropical cyclone event (Cyclone Hamish) with the aim to better resolve the characteristics of this known signal. Our results identify no allochthonous material associated with Cyclone Hamish. Instead, using a swathe of statistical tools typical of ecological studies but rarely employed in the geosciences, we identify new, previously unidentified, signal types. These signals include a homogenising effect, with the level of differentiation between sample sites greatly reduced immediately following Cyclone Hamish, and discernible shifts in assemblage diversity. In the subsequent years following Hamish, the surface assemblage returns to its pre-cyclone form, but results imply that it is unlikely the community ever reaches steady state.
منابع مشابه
Disturbance gradients on inshore and offshore coral reefs caused by a severe tropical cyclone
Tropical storms (cyclones, hurricanes, or typhoons) are the most severe form of mechanical disturbance of coral reefs. In 2005, severe tropical cyclone Ingrid crossed the far northern Great Barrier Reef, a region that had not been affected by a major disturbance for several decades, and where benthic data had been collected before the cyclone crossed. This storm provided a unique opportunity to...
متن کاملImpacts and Recovery from Severe Tropical Cyclone Yasi on the Great Barrier Reef
Full recovery of coral reefs from tropical cyclone (TC) damage can take decades, making cyclones a major driver of habitat condition where they occur regularly. Since 1985, 44 TCs generated gale force winds (≥17 metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the hurricane strength TCs (≥H1-Saffir Simpson scale; ≥ category 3 Australian scale), TC Yasi (February, 2011) was t...
متن کاملRemote Sensing Assessment of Forest Disturbance across Complex Mountainous Terrain: The Pattern and Severity of Impacts of Tropical Cyclone Yasi on Australian Rainforests
Topography affects the patterns of forest disturbance produced by tropical cyclones. It determines the degree of exposure of a surface and can alter wind characteristics. Whether multispectral remote sensing data can sense the effect of topography on disturbance is a question that deserves attention given the multi-scale spatial coverage of these data and the projected increase in intensity of ...
متن کاملQuaternary Morphology and Paleoenvironmental Records of Carbonate Islands
Here I use a simple numerical model of reef profile evolution to show that the presentday morphology of carbonate islands has developed largely in response to late Pleistocene sea level oscillations in addition to variable vertical motion and reef accretion rates. In particular, large amplitude 'ice-house' sea-level variability resulted in long lagoonal depositional hiatuses, producing the morp...
متن کامل