Physics First Ever

Researchers have captured the first-ever footage of individual snow particles moving inside the blinding powder cloud of a massive avalanche.

March 31, 2026

Original Paper

First Direct Observations of Internal Flow Structures in a Powder Snow Avalanche: Turbulence, Instability and Particle Distribution

Ivan Calic, Filippo Coletti, Betty Sovilla

arXiv · 2603.28144

The Takeaway

Scientists have historically been unable to see inside the 'airborne' layer of an avalanche because the thick powder blocks all light. By using high-speed imaging to track individual grains in a natural avalanche, researchers can finally see the internal turbulence and 'waves' that make these flows so destructive.

From the abstract

Powder snow avalanches are highly dynamic, multiphase gravity-driven flows typically composed of a dense basal layer overlain by airborne layers in which snow particles are suspended within a turbulent air phase. Despite extensive work on related systems such as pyroclastic density currents and turbidity currents, all gravity current communities face a fundamental limitation: the lack of direct, high-resolution particle-scale field data. Here, we present the first direct optical observations of