Numerical modelling of river deltas on Titan and the Earth

English Abstract:

Fluvial processes change the landscape by removing surface material from one place and depositing it in another. Beside Earth, terrains shaped by fluvial activity are known from Mars and Titan. When the river enter the standing body of water, the material carried by the flow is deposited, creating specific landforms such as river deltas. Several factors are known to affect the shape and development of these deposits. The sediments might contain different mixtures of clay, sand or gravel-sized grains depending on the terrain and distance from the source, due to natural sorting of rocky material in streams and rivers. We investigated the role of grain size in shaping the river deltas in terrestrial and Titanian environment using numerical approach. This work is an extension of Witek and Czechowski (2015, Planet. Sp. Sci. 105, 65–79). The gravity and the chemistry are substantially different on these celestial objects, but the underlying physics is the same. We found many similarities in evolution of river deltas in both environments, such as the dependence of the delta slope and surface area of the delta plain on the grain size. In particular, the slope is smaller and larger part of the delta is submerged for smaller grains (silt, fine sand).