Extreme Hazards Flashcards
1
Q
What is a tsunami?
A
A tsunami is a series of long, high sea waves. They are caused when an Earthquake, volcano or landslide happens on the ocean floor and displaces the water.
2
Q
How are tsunamis formed?
A
[http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/tsunami.html]
Water is displaced by an earthquake, volcano or landslide.
- Tsunami waves form above the disturbance
- Waves travel outwards in all directions
- The water becomes shallower closer to the coastline.
- The shallower water causes the wave to slow down and increase in height.
3
Q
What magnitude does the earthquake need to be to trigger a tsunami?
A
7.0
4
Q
How does an underwater volcano cause a tsunami?
A
- A volcanic blast displaces the water
2. Tsunami waves travel outwards in all directions.
5
Q
How does a Composite Volcano cause a tsunami?
A
- A pyroclastic flow displaces the water
2. Tsunami waves travel outwards in all directions.
6
Q
How does a landslide cause a tsunami?
A
- Debris from a landslide enters the sea and displaces the water.
- Tsunami waves travel outwards in all directions.
7
Q
What caused the Indian Ocean Tsunami?
A
The Indian Ocean tsunami of 2004 was caused by plates moving and slipping under the ocean.
