Each spring, under the effect of waves, the edges of the northern hemisphere’s ice floes fracture into millions of fragments. Scientists from the PMMH physics and mechanics of heterogeneous environments laboratory (CNRS / ESPCI Paris-PSL / Sorbonne Université / Université Paris Cité) are trying to understand the parameters and conditions that cause the dislocation of ice floes in what are known as marginal ice zones, which stretch hundreds of kilometres. As it happens, these zones, located on the border between the sea and the pack ice, are expanding due to intensified seasonal melting, making the ice field more fragile.