Mon Prof Augmenté
Seafloor Break Lifts the Sea
Deep under the ocean, a fault in the rocky floor can slip in an instant. One block of rock jerks upward, shoving a huge amount of water up and sending waves racing outward across the surface.
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In the picture
- Crack in the seabed rock where the two blocks meet
- Rock block thrust upward above the other
- Mound of water pushed up above the raised rock
- Wave crests spreading outward across the surface
Examples
- Dropping a big stone into a pond makes rings of ripples spread to the shore.
- Jumping into a swimming pool pushes water outward in waves that slap the walls.
Key takeaways
- A tsunami starts when the seafloor moves and lifts the water above it.
- Out at sea the waves are low and far apart, but they grow tall near the shore.
Carry on in the app
Three questions on this lesson. It has left the free week, so its quiz is for subscribers.
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