Beach ridge plain evidence of a variable late-Holocene tropical cyclone climate, North Queensland, Australia

Abstract

To date most studies of long-term tropical cyclone records from beach ridge plains (coral, shell and sand) have suggested that there has been little variation in the intensity of these events over the late Holocene. This study, of a sand beach ridge plain in northeast Queensland, Australia, using sedimentary analysis and luminescence chronology, suggests there has been considerable variation in both the intensity and frequency of tropical cyclones here since the mid-Holocene. Most of the previous beach ridge studies have been of relatively uniform elevation coral shingle, shell and sand beach ridges within the plain. Here, at Rockingham Bay the sediments are composed of coarse-grained sand and there is considerable variation in ridge height and the number of ridges emplaced over different time intervals. It may be that pure sand ridges provide a more sensitive record of variations in long-term tropical cyclone climatology which in turn may contribute to a considerably improved understanding of the behaviour of this natural hazard.