Wave-induced sediment and rhodolith mobility on a narrow insular shelf dominated by wave variability (Fernando de Noronha Archipelago, Brazil)

A seasonal wave regime significantly influences sediment and rhodolith mobility on the narrow insular shelf of Fernando de Noronha, Brazil. The study reveals that summer swell waves from the north increase sediment movement along the northern coast, while winter trade wind waves from the southeast and southern swells affect the southern face. Wave-induced sediment mobility occurs across the entire shelf, up to 60 meters deep near the shelf break, with carbonate bioclastic sediments being remobilized intensely in nearshore zones. Rhodolith movement, less dense but larger than sediments, happens under extreme wave conditions up to 30 meters depth, varying seasonally based on predominant wave direction. This research combines numerical modeling and empirical equations to describe spatial fields of sediment and rhodolith mobility, providing insights into the interaction between wave climate variability and shelf morphology.

Ambrosio, B. G., Takase, L. S., Stein, L. P., Costa, M. B., & Siegle, E. (2022). Wave-induced sediment and rhodolith mobility on a narrow insular shelf dominated by wave variability (Fernando de Noronha Archipelago, Brazil). Continental Shelf Research, 235, 104662. https://doi.org/10.1016/j.csr.2022.104662