ripple effect
The continuing impact that one thing or event has on others. She always hoped that the kindness she showed others would have a positive ripple effect through her community. Many people believe that the flapping of a butterfly's wings can cause a ripple effect that impacts weather patterns hundreds of miles away.
a ˈripple effect
a situation in which an event or action has an effect on something, which then has an effect on something else: His resignation will have a ripple effect on the whole department.A ripple is a small wave on the surface of a liquid, especially water in a lake, etc.