Evolution of Barrier Island-Lagoon Systems from 200 KA Ago to the Present in the Littoral Zone of Alicante (Spain). Impact of a Probable Sea Level Rise

Abstract

The distribution of barrier island-lagoon systems of the littoral zone of Alicante is controlled by tectonics. They occur in areas of subsidence to E-W oriented synclines and also to downthrown blocks of dextral faults oriented N 120°–140° E having some vertical movement. Separation of lagoons begun during the Middle Pleistocene but the Tyrrhenian beach ridges are the most prominent morphological feature. The subsiding trend of tectonic origin continued during Holocene times in the same areas, although progradation of beach systems was greatly reduced. In recent (historic) times, progradation has been further diminished due to building of dams along the Segura and Vinalopó rivers which are the main contributors of sediment to the coastal budget. Detailed morphological study of the beach ridges closing lagoons revealed a higher degree of subsidence in the area of Torrevieja since Tyrrhenian times to the present and a positive (although small) rate of progradation off the lagoons of Santa Pola and El Saladar.