Fig. 9

Shear induced folding in the ML model, with parameters as in Fig. 5. The red curve in all panels represents the limit cycle of the unperturbed system, whilst the green dotted line represents the stable manifold of the saddle node, indicated by the orange marker. We begin distributing points along the limit cycle and then apply an instantaneous kick taking $v\mapsto v+\epsilon$, where $\epsilon =-2.0$, leaving w unchanged. This essentially moves all phase points to the left, to the blue curve. The successive panels show the image of this set of points after letting points evolve freely under the system defined by the ML equations, and then apply the kick again. The curves shown are the images of the initial phase points just after each kick, as indicated in the figure. We can clearly observe the shear induced folding. Parameter values as in Appendix B.1