Book 6, Question 22
Why Do Rocks Get Holes By the Sea?
Waves throw sand and pebbles at rocks. Soft spots wear away first. Some animals also drill tiny homes in the rock. Do not put fingers in mystery holes, since animals may live there.
From the book
Page from A Million Whys Book 6
More fun facts
- Abrasion happens when waves throw rocks and pebbles against cliffs and wear them away.
- Attrition happens when rocks carried by the waves smash into each other and become smaller, rounder and smoother.
- Cliffs usually form where the rock is harder and resists the sea better.
- Scientists exploring the deep seafloor found lines of mysterious holes, and they still are not sure what made them.
- Rock cores drilled from the seafloor hold layers that tell the story of the last 200 million years or so.
Sources: BBC, NOAA Ocean Exploration, Science News Explores
Questions kids ask
What is abrasion?
It is when waves fling rocks and pebbles against cliffs, slowly wearing the cliffs away.