Large-scale coastal features generated by atmospheric pulses and associated edge waves Elena Quevedo, Asunción Baquerizo, Miguel A. Losada, M. Ortega-Sánchez ⁎ Grupo de Puertos y Costas. Centro Andaluz de Medio Ambiente. Universidad de Granada. Avda. del Mediterráneo, s/n. 18006 Granada, Spain Received 10 April 2007; received in revised form 6 September 2007; accepted 2 October 2007 Abstract This article presents a hydrodynamic model that predicts the generation of horns and coves on the inner continental shelf, resulting from turbulent wind vortices blowing over the sea surface on the lee side of geographic obstacles (e.g. capes, islands, skyscrapers etc.). Such vortices generate edge waves whose net bedload sediment transport leads to the formation of such features. The resulting morphology reinforces the standing edge wave pattern, produces positive feedback, and exhibits self-forcing behavior. This model is applied to the horns and embayments found at Carchuna Beach (Spain), and offers a plausible explanation of how they have been generated. The results show that the presence of geographic obstacles or human constructions close to a beach may cause the formation of large-scale features on its coastline, significantly altering the beach width. © 2007 Elsevier B.V. All rights reserved. Keywords: Large-scale features; Wind vortices; Edge waves; Numerical modeling; Video-images 1. Introduction The morphology of the coast is determined by com- plicated interactions between waves, currents, sediment transport and the coastal geology and morphology itself. This complexity is increased due to the wide range of scales covered by the landforms, which include from small-scale features such as beach cusps (few meters) to large-scale features (even hundreds of kilometers) that may configure the coastline itself (Pethick, 1984). Between the different coastline morphological features, approximately 40% of the world's coastline is formed by beaches consisting of unconsolidated deposits of sand and gravel on the shore (Bird, 2000), which are by definition dominated by waves, being amongst the most dynamical physical systems on earth (Short, 2000). Beaches commonly show projections of sediment that trend at right angles to the shoreline and are known with different nomenclatures such as beach cusps, shoreline sand waves, rhythmic features or giant cusps (Komar, 1998). They commonly occur in series with a fairly uniform spacing (defined as the horizontal distance between successive cusps), although they can also appear isolated or not uniformly spaced (Ortega- Sánchez et al., 2003). Numerous competing hypotheses and models based on diverse conceptions of the im- portant forces and interactions have been advanced to explain such beach morphological features (Komar, 1998; Short, 2000). Although different research studies Marine Geology 247 (2008) 226 – 236 www.elsevier.com/locate/margeo ⁎ Corresponding author. E-mail addresses: equevedo@ugr.es (E. Quevedo), abaqueri@ugr.es (A. Baquerizo), mlosada@ugr.es (M.A. Losada), miguelos@ugr.es (M. Ortega-Sánchez). 0025-3227/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.margeo.2007.10.005