Mon Prof Augmenté
Seafloor Lift Starts a Tsunami
Age 14 · Geography
An undersea earthquake can suddenly lift a block of the ocean floor. The lifted floor pushes the water above it, starting a long wave that can travel across the ocean toward a coast.
This picture is part of the full library
Every lesson is open to everyone for 7 days after it is published. This one came out on September 22, 2026: its text stays readable here, and its picture opens with a subscription.
The app is free. A subscription opens every lesson, in every school year.
In the picture
- Raised seabed block: a section of ocean floor pushed upward
- Swollen water surface: seawater lifted above the raised block
- Long wave crest: a broad swell moving across the ocean surface
- Small boat: a vessel riding on the ocean surface
- Coastal town: low buildings at the shoreline in the wave’s path
Examples
- Dropping a heavy stone into a bathtub makes ripples spread across the water.
- Pushing up the bottom of a full water bottle makes the surface rise and spill.
Key takeaways
- An undersea earthquake can move the seafloor and displace a large volume of water.
- A tsunami travels as long, low waves in the open ocean and can rise near the shore.
Quiz: Seafloor Lift Starts a Tsunami (Age 14)
-
According to the card, what can start a tsunami?
-
How does a tsunami move in the open ocean, according to the card?
-
When an undersea earthquake lifts a block of the seafloor, what happens to the water above it?
The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.
Free app, optional subscription
App Store Google Play
Carry on in the app
At least one new illustrated lesson every weekday for your child’s year, with its quiz and a reminder at 6:15 pm.
Your child’s teacher does not use My Enhanced Teacher yet?
Tell them about it
