MONITORING OF THE COASTAL DYNAMICS ON THE SAND SPIT AT TORTUGUEROS BEACH, MEXICO

Abstract

Sand spits occur worldwide in different shapes, from a single, relatively simple arc to an irregular, crenulated, and complex barrier. Cross-shore and longshore sediment transport often influence spit dynamics (Nagarajan et al., 2015), strongly linked to wave energy and sediment supply. The present analysis focuses on a dynamic and complex spit at Tortugueros beach, a re-entrant bay, 1 km in length, on the Gulf of Mexico. Tortugueros beach is a wave-dominated beach with very fine to fine sand that forms a fairly gentle sloping beach profile. The sediment sources are longshore sediment transport and onshore sandbar migration, while sediment loss is due to long- and cross shore (during storms) transport. The region is micro-tidal, with mean and maximum high tide levels of 0.18 m and 0.92 m above the mean sea level. Given the high dynamics of the Tortugueros beach spit system and the lack of data measured on the beach, a monitoring system was developed to collect field data regularly to help us improve the understanding of the functioning of the coast on this beach, and the international knowledge related to the formation and morphological evolution of this type of spits in other similar beaches around the world.