Depth Dependence of the Big Wave in Belousov-Zhabotinsky Reaction

Hydrodynamical effects due to Marangoni instability in the Big Wave, which is the wave observed in a quasi 2-dimensional shallow layer of unstirred excitable Belousov-Zhabotinsky (BZ) reaction solution, were investigated experimentally. We found that the layer depth of BZ solution strongly influences the propagating velocity and the shape of the wave. The critical depth d c of BZ solution was found to be d c ≈1.5 mm. The qualitative feature of the propagation of the wave changed at d c . We also determined the difference between the location of the maximum deformation of the surface and that of a wave front such as the color front.