Beaches Of Rio Grande Do Norte

The Rio Grande do Norte coast extends 410 km, and consists of sandy beaches (72 %), active sea cliffs carved into Cenozoic sediments of the Barreiras and Tibau formations (26 %), and transgressive dune fields and beachrock. It comprises two different sectors: the northern (equatorial) coast trends east for 244 km, while the eastern (oriental) coast trends south for 166 km. The eastern sector is characterized by wave-dominated and some tide-modified beaches that are mainly reflective to intermediate states. In contrast, the northern sector has resulted in tide-modified and tide-dominated beaches that range from reflective (the dominant state) to intermediate. In general the Refletive + Low tide terrace (R + LTT) is present along the entire coast for most of the year, while wave-dominated Longshore bar and trough (LBT), Rhythmic bar and beach (RBB), Transverse bar and rip (TBR), Low tide terrace (LTT) and reflective (R) occur along the eastern sector, and tide-dominated Beach + tidal sand flats (B + TSF) occurs along parts of the northern sector. R + rock flats and coral reef flats are present in both sectors, where bedrock and beachrock reefs are prevalent. Beachrock reefs are very common along the Rio Grande do Norte shore, occurring in both the offshore and onshore zones. Beach morphodynamics is modified due the presence of the beachrocks. Sea level variability is dominated by tides (up 98 % of the energy spectra). The sea level subtidal component is well correlated with the winds, but demonstrate very low amplitudes. Longshore currents are wind modulated, while cross-shore currents are primarily modulated by tides and secondarily by winds. Erosional hotspots and, both natural and anthropogenic hazards, are present along the Rio Grande do Norte coast.