If your kid loves the beach, they know cresting and crashing waves are beautiful to watch as they roll into shore. But do they know what causes waves? Or how important waves are to the shoreline? They will! Here are some fun facts to share with your kids about waves and erosion next time you’re at the beach.
Waves are commonly caused by wind, although they can also be caused by underwater disturbances, like earthquakes or volcanic eruptions. The largest wind-driven waves form when the wind is very strong and blows steadily for a long time, over a great distance.
Waves can also be caused by the gravitational pull of the moon and sun. These are called tides.
Waves cause erosion at the shoreline and deposit sand on beaches. They erode cliffs and rocks, and transport those sediments onto beaches. The amount of sand on the beach can grow or shrink depending on the waves’ energy. In the summer, waves have lower energy so they bring sand up onto the beach. In the winter, higher energy waves pull the sand back offshore.
The constant motion waves slowly erodes larger rocks into smaller stones, and then those smaller stones finally turn into tiny sand particles. There are usually old shells mixed in there too, and often pieces of glass that have been polished smooth by the constant churning, which all makes for great treasure hunting!
A fun way to bring this lesson back home with your kid is to try polishing stones yourselves. You can make smooth, polished rocks or sea glass at home with our National Geographic Rock Tumblers! From the beginner up to professional level, there is a model that will suit your needs!