Upper panel: density profile in the cross-section at the loop apex for the simulation with and a critical resistivity, η^∗ = 10^-4. As in Fig. 3, the density is normalised to the initial exterior density, ρ_e. Regions in which the critical resistivity, is triggered are overplotted in red. Lower panel: difference plot between the density in the simulation and the simulation where η^∗ is considered. Red regions indicate larger densities in the simulation including η^∗ and blue regions indicate larger densities in the original case.