Recall what happens when a stone is tossed into a lake, as all of us have done—if not, try it. First, there is a depression where the stone falls and an accompanying splash. Then, there are a series of surface gravity waves that radiate out from the center of splash site. The stone imparts both kinetic and potential energy upon the sea surface and the waves provide a way by which this energy is transmitted away from the impact site. At some point in time, the impact site will settle down, and a packet of waves will be seen propagating away in a circular fashion with longer wavelength waves leading the pack. Being that wave energy is spread along the crests in ever-growing circles, the entire event will slowly peter out as these waves get farther from the source.