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Speaker: Julia Cisneros, NSF Postdoctoral Fellow, Research Affiliate, The University of Texas at Austin Jackson School of Geosciences

Host: Marcy Davis

Title:  The morphology of alluvial sand dunes

Abstract: In the process of sediment transport through a shearing flow, dunes are forming and simultaneously recording their surrounding conditions. These records offer clues about the movement of wind and water across an ancient, otherwise unknown, landscape. In turn, dunes are influencing how sediment is transported. Key to leveraging these records of ancient environments is our understanding of the links between flow, sediment transport, and bedform morphodynamics. To gain that critical understanding, we use modern bedforms to understand the conditions of the Earth and planetary systems and improve how contemporary environments are managed.

This talk will highlight research that aims to investigate dune formation and dune shape in big and small rivers and in shallow laboratory flows. This investigation allows the comparison and validation of the key processes controlling the formation of low-angle dunes. I then identify and discuss the conditions when one process may dominate in creating complex dune shapes. This talk highlights the balance between bedform superimposition and sediment suspension as controls on the formation of low-angle dunes. This information is vital to improving our approach to managing contemporary rivers under modern stressors and revealing the deposits of ancient rivers.