Copy frames 1 to 10 -> To do this click frame 1, press Shift key and click frame 10 (the frames will be heighlighted), now press Ctrl+Alt+C to copy the frames.
Add a new layer, click the 4th frame on the timeline and paste the copied frames (press Ctrl+Alt+V).
Add another new layer, click the 8th frame on the timeline and paste the copied frames (press Ctrl+Alt+V).
Repeat the above step leaving 4 frames more than the previous layer for as many layers as desired.
Save your work and test the Movie (Ctrl + Enter). That's it, your cool ripple effect is ready!