He threw a stone in the pond,and the water riffled for a long while and lay quiet again.

After dropping a small stone into still water, we saw ripples going out in all directions.

If this happens on a large scale, as it did in the 1930s, the ripple effect for the economy as a whole can be devastating.

It's a bit like if you're pushing a boat through a river and measuring something about the surface - you don't want to measure the ripples from the boat.

The flowing river showed minor ripples in the reflection, even though the wind was dead calm.