Vendredi 14 mars à 11h00, salle 250 / IUSTI
Abstract: In glaciology, karstology, speleology or planetology, regular and periodic patterns are often observed on dissolving, melting or sublimating solid substrates. One of the most common is known as scallops, and consists of a cellular pattern of cups-like concavities surrounded by very sharp crests. They can be found typically on the walls of limestone caves carved by underground rivers. Yet very similar patterns form on the immersed part of icebergs, on high-altitude glaciers or on the surface of meteorites during their entry into the atmosphere. The similarity between these patterns, despite the wide range of materials and hydrodynamic conditions, suggests a common and general mechanism. By comparing field measurements, numerical models and experiments, we propose a geometric approach to explain the generic emergence of scallops [1]. This mechanism confirms that the formation of sharp structures is largely independent of the details of the flow but rather results from a geometric mechanism. Then, we show in the field and in experiments then that the presence of a flow induces an asymmetry in dissolution and melting pattern.
[1] M. Chaigne, S. Carpy, M. Massé, J. Derr, S. Courrech du Pont, M. Berhanu, Emergence of tip singularities in dissolution patterns. Proceedings of the National Academy of Sciences 120(48), e2309379120 (2023).