Evolution of the bar strength A₂ (top panel), median vertical coordinate of particles (middle panel), and mean vertical velocity (bottom panel). All frames show the evolution of parameters at different radii in a circular annulus of 0.5 kpc width: from blue in the center to brown lines at the outskirts. To improve the visibility of the ⟨z⟩,⟨ν_z⟩ time-dependent variations we shift each curve relative to the previous by a constant value of δ_vi = 0.2 and δ_ri = 0.05 for vertical velocity and vertical coordinate respectively. The end of the bar buckling phase corresponds to ≈1 Gyr.