FIG. 2 (color online). (a) Diffusing light image of the fluid
surface elevation including floating particles. The particle diameter
here is 300 m [24]; the peaks and troughs of the
oscillons appear as dark and white blobs. (b) Trajectories of
oscillons (black) having a phase maximum in (a), and trajectories
of eight particles (colored) tracked for 2 s (200 periods of the
shaker). (c) Wave number spectra of the surface elevation at
different vertical accelerations (a ¼ 0:7, 1.2, and 1.6 g) and
f0 ¼ 60 Hz. (d) Frequency power spectra of the Lagrangian
velocity (averaged over 1000 trajectories) for different vertical
accelerations at f0 ¼ 60 Hz.