Examinando por Materia "Tropics"

Mostrando 1 - 3 de 3
  • No hay miniatura disponible
    Ítem
    Dendrogeomorfología aplicada a la evaluación de avenidas torrenciales en la Quebrada Juan García, afluente del Río Cauca, Andes del Norte, Colombia
    (Universidad EAFIT, 2021) Yepes Bonilla, Santiago; Urueña Ramírez, David Alejandro; Marín Cerón, María Isabel; Noriega Londoño, Santiago; Restrepo Moreno, Sergio Andrés
  • No hay miniatura disponible
    Ítem
    Morphodynamics of a high discharge tropical delta, San Juan River, Pacific coast of Colombia
    (ELSEVIER SCIENCE BV, 2002-12-30) Restrepo, JD; Kjerfve, B; Correa, ID; Gonzalez, J; Universidad EAFIT. Departamento de Geología; Ciencias del Mar
    The San Juan River has one of the most extensive and best developed deltas on the Pacific coast of South America, measuring 800 km2. The river drainage basin measures 16465 km2 and is located in one of the areas with the highest precipitation in the western hemisphere. The annual rainfall varies from 7000 to 11 000 mm, and as a result the San Juan River has the highest water discharge (2550 m3 s-1), sediment load (16×106 t yr-1), and basin-wide sediment yield (1150 t km-2 yr-1) on the west coast of South America. The San Juan delta growth began approximately 5000 years BP. The structure of the delta is determined by the interactions between fluvial deposition and the effect of 1.7-m significant swells, mostly from the SW, and strong tidal currents. Analysis of delta progradation indicates that during 1848-1992 the morphology of the delta was characterized by beach ridge accretion, spit growth, narrowing of inlets, and a general advance of the delta shoreline. During the past decade processes such as rapid erosion of the delta shore, narrowing of barrier islands, and breaching of a new inlet, are the result of a long-term relative sea-level rise of 2.6 mm yr-1 due to tectonically induced subsidence coupled with a eustatic rise of sea-level. The delta also experiences strong oceanographic manifestations associated with the El Niño-La Niña cycle, causing regional sea-level elevation of 20-30 cm during El Niño years. Recent coastal subsidence in the delta is evidenced by (1) increased occurrence of non-storm washover events; (2) increased erosion of barrier islands with average loss of 11 m yr-1 during 1993-1997; and (3) a relative sea-level rise of 3.4 mm yr-1 during 1991-1999. The morphology and recent evolution of the San Juan delta are unique when compared to other deltas of South America because of the singular combination of extreme climatic, geologic, and oceanographic conditions under which the delta has formed and the absence of human-induced impact in the drainage basin. © 2002 Elsevier Science B.V. All rights reserved.
  • No hay miniatura disponible
    Ítem
    Preliminary geochemical study of thermal waters at the Puracé volcano system (South Western Colombia): An approximation for geothermal exploration
    (Universidad Industrial de Santander, 2018-01-01) Gómez-Díaz E.; Marin-Cerón M.I.; Gómez-Díaz E.; Marin-Cerón M.I.; Universidad EAFIT. Departamento de Ciencias; Geología Ambiental y Tectónica
    The Puracé Volcano is located in the Cauca department, SW of Colombia, along the Coconucos volcanic chain. This volcano is an interesting target for geothermal exploration, because it is a young caldera-type volcano, with thermal activity (e.g. hot springs and fumaroles). Using hydro-geochemical analyses of hot springs, we determine the type of water, origin and relation with the geothermal system, reservoir temperature, mixing process and finally the potential areas for future exploration. The analyzed water-types are bicarbonate, dilutechloride, sulphate-chloride, acid-sulphate and heated steam-acid sulfated. The conservative elements, allow to identify the correlation between different springs and to infer commune sources. Moreover, the applied solutes geothermometers for each suitable thermal-water group were used to estimate the reservoir temperature. The Silica geothermometers resulted within a range of 120°C -170°C while those the Cation geothermometers are above these temperatures reflecting values from 160°C to 220°C. However, the Cation geothermometer of low temperature clearly identify another zone of lower temperature. Mixing and recharge processes, were identified through of stable isotopes. Finally, the preliminary geothermal model shows two zones of high enthalpy system ( > 150°C). © 2018, Boletín de Geología.