Cyprien Morize
Université Paris-Saclay & UBA - Conicet

Large waves can be generated when landslides or other granular masses suddenly enter a body of water. But how does the motion of the grains control the resulting waves?

In this colloquium, I will present laboratory experiments on impulse waves generated by the collapse of granular columns into water. Starting with dense grains in a two-dimensional channel, I will discuss the different wave regimes and show how their dynamics can be characterized by a local Froude number. I will then introduce a simple physical model to predict the wave amplitude from the initial geometry of the granular column.

Finally, I will explore how this picture changes when the grains are buoyant or when the collapse takes place in an axisymmetric geometry.

These results provide a framework for understanding wave generation by rapid granular motions, with implications for landslide-generated tsunamis.