2 min read
Tsunamis
A tsunami is a series of large ocean waves from sudden water displacement; near coasts speed falls while height can rise sharply.
Choose Your Level
Tsunamis
A tsunami happens when a huge amount of ocean water is suddenly displaced, often by an undersea earthquake.
Recommended for Class 10
Tsunamis
A tsunami is a series of large ocean waves produced by the sudden displacement of a large volume of water.
Common causes include:
undersea earthquakes; submarine landslides; * volcanic activity.
Deep Ocean
In deep water, tsunami waves can travel at very high speed while having relatively small height and very long wavelength.
Near the Coast
As the wave enters shallower water:
its speed decreases; wavelength decreases; * wave height can increase significantly.
This process makes tsunami waves dangerous near coastlines.
Important Distinction
A tsunami is not simply a normal wind-generated ocean wave.
It involves motion of a much larger water column and has a much longer wavelength.
Warning
Seismic monitoring, ocean buoys and coastal warning systems can help detect tsunami hazards.
Tsunamis — Advanced
Tsunamis are shallow-water gravity waves with extremely long wavelengths. Their speed depends strongly on water depth. As they enter shallow regions, energy is compressed into a shorter wavelength and wave height grows.
Common Mistakes
Common Mistakes
- Mistake
A tsunami is not necessarily one single wave.
- Mistake
It does not become dangerous only because it “moves faster” near the coast; in fact its speed usually decreases in shallow water while height increases.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
Cause → water displacement
Deep → fast + low height
Shallow → slow + taller
- Definition
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.
Ready to test yourself?
You've completed the learning section.
Practice
PQ
Q1. Define tsunami.
PQ
Q2. State causes.
PQ
Q3. Deep-water behaviour.
PQ
Q4. Shallow-water changes.
PQ
Q5. Warning systems.
Exam Practice
EQ
Q1. Define tsunami.
EQ
Q2. State three causes.
EQ
Q3. Explain behaviour in deep ocean.
EQ
Q4. Explain why wave height grows near coast.
EQ
Q5. Explain one warning method.
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.