Print Email Facebook Twitter A Sand-Gravel Gilbert Delta Subject to Base Level Change Title A Sand-Gravel Gilbert Delta Subject to Base Level Change Author Chavarrias Borras, V. (TU Delft Rivers, Ports, Waterways and Dredging Engineering) Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering) Orru, C. (TU Delft Environmental Fluid Mechanics) Martín-Vide, Juan Pedro (Universitat Politecnica de Catalunya) Viparelli, Enrica (University of South Carolina) Date 2018 Abstract Laboratory experiments were conducted on a sand-gravel Gilbert delta to gain insight on its dynamics under varying base level. Base level rise results in intensified aggradation over the topset, as well as a decrease in topset slope and topset surface coarsening, the signals of which migrate in an upstream direction. Preferential deposition of coarse sediment in the topset results in a finer load at the topset-foreset break, which creates a fine signature in the foreset deposit. Base level fall has the opposite effects. Entrainment of the topset mobile armor causes a coarsening of the load at the topset-foreset break and so a coarse signature in the foreset deposit. The entrainment of the topset substrate and fine top part of the foreset may follow, which causes a fining of the load and a fine signature in the foreset deposit. The fact that the upstream sediment supply requires a certain slope and bed surface texture to be transported downstream under quasi-equilibrium conditions counteracts the effects of base level change. This information travels in the downstream direction. In nature base level change is likely so slow that the upstream sediment load maintains the topset slope and bed surface texture and so keeps the topset in a quasi-equilibrium state. Base level change is therefore not expected to leave a clear signal in a mixed-sediment Gilbert delta other than a change in elevation of the topset-foreset interface. Subject Gilbert deltaImage analysisMixed-sedimentMorphodynamicsSize stratification To reference this document use: http://resolver.tudelft.nl/uuid:e0188634-8b62-4439-8fd2-e5b1a1ce3447 DOI https://doi.org/10.1029/2017JF004428 ISSN 2169-9003 Source Journal of Geophysical Research: Earth Surface, 123 (5), 1160-1179 Part of collection Institutional Repository Document type journal article Rights © 2018 V. Chavarrias Borras, A. Blom, C. Orru, Juan Pedro Martín-Vide, Enrica Viparelli Files PDF Chavarr_as_et_al_2018_Jou ... rface_.pdf 3.14 MB Close viewer /islandora/object/uuid:e0188634-8b62-4439-8fd2-e5b1a1ce3447/datastream/OBJ/view