Phase diagram associated with Eq. (17) and n = 1, for a<a_crit (top) and a>a_crit (middle). The solid line is the path of a blob with initial position s(0) = 0.45L and initial velocity v(0) = −10^-5ω/k. The dashed line is the path of a blob with the same initial conditions in the absence of an oscillation (a = 0). The bottom panel shows the distance along loop of the blobs as a function of time for the three cases.