Coastal Dynamics and Geomorphology of the Pozos Colorados Sector, Santa Marta: An Analysis of Sea Level Rise and Paleo-shoreline

Diego Andres Villate Daza^1,2Eduardo Barboza^2*Bismarck Jigena-Antelo^3*Juan Jose Munoz-Perez³Giorgio Anfuso³Luana Portz⁴Fernando Afanador-Franco⁵Rogerio Portantiolo-Manzolli⁶

• ¹CASEM (Andalusian Higher Center for Marine Studies), Puerto Real Campus, Av. República Saharahui s/n, 11510, Puerto Real (Cádiz), Spain, University of Cádiz, Cádiz, Spain
• ²Programa de Pós-graduação em Geociências – Instituto de Geociências da Universidade Federal do Rio Grande do Sul – UFRGS. Av. Bento Gonçalves, 9500, Prédio 43113, Sala 207 (Bloco I), Bairro Agronomia, Porto Alegre, RS CEP 91501-970, Brazil, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
• ³University of Cadiz, CASEM (Andalusian Higher Center for Marine Studies), Puerto Real Campus, Av. República Saharahui s/n, 11510, Puerto Real (Cádiz), Spain, University of Cádiz, Cádiz, Spain
• ⁴Departamento de Geodinámica, Estratigrafía y Paleontología, C/ José Antonio Novais, 12 Ciudad Universitaria, Madrid Spain, Universidad Complutense de Madrid, Madrid, Spain
• ⁵Caribbean Oceanographic and Hydrographic Research Center (CIOH), Integrated Coastal Zone Management Sec-tion, El Bosque neighborhood, Manzanillo Island, “Almirante Padilla” Naval School, Cartagena de Indias, Co-lombia, Centro de Investigaciones Oceanograficas e Hidrograficas, Cartagena, Colombia
• ⁶Institute of Oceanography, Universidade Federal do Rio Grande -IO/FURG, Rio Grande, Brazil, Universidade Federal do Rio Grande, Rio Grande, Brazil

The coastal dynamics of the Pozos Colorados sector in Santa Marta, Colombia, are controlled by the interaction of eustatic sea-level variations, sedimentary imbalance, and intense human interventions, which together condition the morphodynamic response of this microtidal coast. This study applies an integrated, multi-scalar approach combining geomorphological mapping, satellite remote sensing, quantitative shoreline-change analysis (via CoastSat), and Ground Penetrating Radar (GPR) profiling to reconstruct the evolutionary trajectory of the coastal system and assess its vulnerability. Results reveal a net shoreline retreat of –2.0 m yr⁻¹ between 1986 and 2024, with maximum erosion during 1986–1996 and localized accretion after 2021, modulated by sediment supply and coastal engineering works. The identification of twelve geomorphological units allowed recognition of inherited fluvial– marine features that exert first-order control on present-day coastal behavior. Paleo–sea-level reconstructions document highstand transgressions up to +6 m during MIS 5e and +3 m in the mid-Holocene, establishing the morphostratigraphic framework that dictates current coastal susceptibility. The integration of surface and subsurface datasets demonstrates the effectiveness of combining remote sensing and geophysical tools for diagnosing erosional regimes and forecasting inundation scenarios. This comprehensive approach enhances the understanding of long-term coastal evolution under Running Title compounded natural and anthropogenic drivers, providing a scientific basis for ecosystem-based management and adaptive spatial planning in this highly dynamic and vulnerable sector of the Colombian Caribbean.