Observations of beach cusp evolution at Melbourne Beach, Florida, USA

Morphological observations (terrestrial laser scanning) and sediment analysis are used to study beach cusp morphodynamics at Melbourne Beach (Florida, USA), a moderately sloped beach characterized by fine sand. The study couples rapid high-resolution surveying with surficial sediment sampling over multiple tidal cycles. Surveys were run ~ 500 m alongshore and sediment samples were collected intertidally over a period of 5 days. Beach cusp location within larger scale beach morphology is shown to directly influence cusp growth as either gross erosional or gross accretional. Sediment characteristics within the beach cusp morphology are reported coincident with cusp evolution. Variations in particle size distribution kurtosis are exhibited as the cusps evolve, however no significant correlation is seen between grain size and position between horn and embayment. During the end of the study, a storm resulted in beach cusp destruction and increased sediment sorting.

Research highlights
► We determine cusp evolution as a function of large-scale geomorphology.
► We determine inter-scalar studies are important in cusp study.
► We examine changes in the sedimentology post-storm at a cusp-laden beach.