Tsunami waves can propagate in all directions. In the deep ocean, tsunami waves can propagate with the speed of 500-1000 km per hour. Wave height in the deep ocean is only about 1 meter. When approaching the coast, the tsunami wave speed decreases to about 30 miles per hour, but its height was increased to tens of meters. Tsunami waves hit can go up to tens of kilometers from the shoreline
• Definition of tsunami
• The causes of Tsunami
• Characteristic of tsunami
• The effect
• Countermeasures of Tsunami
Definition of Tsunami
The displacement of water caused by
changes in sea surface vertically with
The causes of Tsunami
4 causes of sea level changes:
an earthquake centered under the sea
underwater volcanic eruptions
meteor or lacing at sea
Characteristic of Tsunami
Tsunami cause damage by two mechanisms: the smashing
force of a wall of water travelling at high speed, and the
destructive power because of large volume of water.
While everyday wind waves have a wavelength of about 100
meters and a height of roughly 2 meters, a tsunami in the
deep ocean has a wavelength of about 200 kilometers. Such
a wave travels at well over 800 kilometers per hour, but
owing to the enormous wavelength the wave oscillation at
any given point takes 20 or 30 minutes to complete a cycle.
This makes tsunamis
difficult to detect over deep water.
This is the reason for the name "harbor wave".
About 80% of tsunamis occur in the Pacific
Ocean, but they are possible wherever there are large
bodies of water, including lakes. They are caused by
earthquakes, landslides, volcanic explosions.
The Effect to
Enviroment• To People:
-Loss of lives & family.
-Loss of jobs & living.
-Loss of livestock.
-Negative impact on the affected region's economy.
-Negative impact of the affected region's tourism.
• To the Environment:
-Alteration of seaside terrain.
-The sea will be temporarily littered with debris after the
-Coral or Marine Reef damage (In tropical regions).
Countermeasures of Tsunami
• The detector equipment should be well
• Train the people how to overcome the
• Make seawall around the shoreline.
• Preparation of evacuation
• More alert when there is an eartquake above