Process:  - Waves hit the coast - Waves have energy that pushes the water and sediment - The sediment can help erode land like sandpaper - Water washes the sediment back - Some sediment is left as sand.  Perturbation hypothesis: suppose a tsunami occurs and creates huge waves happens, how will it affect more sediment is eroded from the land.  Does the supposed perturbation have an effect (direct or indirect) on the process?

yes