​This lecture is organised by the Irish Geological Association

Full Abstract

Sediment erosion, transport and deposition by rivers and turbidity currents are key processes responsible for shaping large areas of the natural landscape and seascape. Similar resurfacing of planetary surfaces by liquids associated with a volatile cycle is also inferred for other planetary bodies in the solar system, including Mars and Titan. This talk will consider the sediment transport dynamics of suspended-load dominated flows, and in particular a new model for equilibrium flow conditions, where sediment erosion equals deposition. Understanding this condition is key to predicting some of the most fundamental aspects of sediment laden flows, their effects on the land/seascape and resulting stratigraphic architecture, for example: whether flow will be erosional or depositional, how much sediment they can transport (i.e., their capacity and sediment flux) and what slope gradient they will attempt to achieve (i.e., equilibrium graded slope). Results pertinent to several areas of research will be presented: what are critical slopes of sediment bypass by turbidity currents? How important is particle size distribution in sediment transport? Are graded slopes on Mars and Titan, and by implication the current/past geomorphology of these planetary bodies, similar to those on Earth?

Lawrence Amy Biography. Lawrence has an undergraduate degree in Geological Sciences and a PhD in Deepwater Sedimentology both from the University of Leeds. After his PhD he was a research associate at the University of Bristol and then Edinburgh's Heriot-Watt University, before working in the petroleum industry with Saudi Aramco and Tullow Oil. He is currently an Associate Professor in Petroleum Geoscience at the School of Earth Sciences, University College Dublin. His research topics include turbidite stratigraphic pinch out traps, the structure and stratigraphy of foreland deep-water basins and sediment transport by rivers and turbidity currents on Earth and other planetary bodies.