In order to cause water ripples to form concentric circles what has to happen?

To create water ripples that form concentric circles, a disturbance must occur in the water's surface, such as dropping a stone or creating a splash. This disturbance generates waves that propagate outward from the point of impact, with each wavefront moving in a circular pattern. The energy from the disturbance spreads uniformly in all directions, resulting in the formation of concentric circles as the waves move away from the source. The size and spacing of the circles depend on the strength and nature of the initial disturbance.