ADIW02 | Dr. Cedric Beaume | Contributed talk - Pattern formation on dry salt lakes

Speaker: Dr Cedric Beaume (University of Leeds) Date: 28th Mar 2024 - 13:30 to 13:50 Venue: INI Seminar Room 1 Title: Contributed talk - Pattern formation on dry salt lakes Event: (ADIW02) Mathematical and Computational Modelling of Anti-Diffusive Phenomena Abstract: Dry salt lakes are spectacular geological landscapes that occur in arid environments. The strong evaporation and limited rainfall characteristic of these environments (but also, in certain cases, human intervention!) may progressively deplete existing lakes from their water, resulting in the formation of lakes whose surface appears dry. Below this dry surface, however, the water table is generally not very deep and evaporation remains a driving mechanism for the flow. The dissolved minerals, or salts, present in the depths of the lake are carried upward by the resulting flow and precipitate to form a salt crust at the surface. Salt lake crusts are known to produce polygonal patterns that typically span 1m and are delimited by raised salt ridges. These patterns remarkably display little variation with the location or salt lake considered. Understanding the formation of crust patterns on dry salt lakes is a fascinating problem in itself but it is also key to understand the potential of salt lakes for dust emission and for its control. In this talk, we present a new model for the fluid dynamics that takes place below the crust of dry salt lakes. The lake is modelled using a three-dimensional porous medium subject to a uniform through-flow due to evaporation and forced by the buoyancy generated by the presence of salt: the salt crust at the surface yields a more concentrated, hence denser, fluid in its vicinity. This configuration possesses a simple, spatially homogeneous solution, which is unstable at sufficiently large values of the Rayleigh number. The resulting instability is studied numerically and related to the emergence of polygonal patterns at the surface of the lake. ------------------- FOLLOW US 🌐| Website: https://www.newton.ac.uk 🎥| Main Channel:    / @isaacnewtoninstitute   🐦| Twitter:   / newtoninstitute   💬| Facebook:   / newton.institute   📷| Instagram:   / isaacnewtoninstitute   🔗| LinkedIn:   / isaac-newton-institute-for-mathematical-sc...   SEMINAR ROOMS 🥇| INI Seminar Room 1:    / @iniseminarroom1   🥈| INI Seminar Room 2:    / @iniseminarroom2   🛰️| INI Satellite Events:    / @inisatellite   ABOUT The Isaac Newton Institute is a national and international visitor research institute. It runs research programmes on selected themes in mathematics and the mathematical sciences with applications over a wide range of science and technology. It attracts leading mathematical scientists from the UK and overseas to interact in research over an extended period. 👉 Learn more about us and our events here: https://www.newton.ac.uk