Explanation text

Tsunami

        Tsunami  of are large waves of water caused by disturbances on the ocean floor, such as earthquakes. This disturbance forms waves that spread in all directions with wave speeds reaching 600-900 km / hour.Initially the wave has a small amplitude (generally 30-60 cm) so it is not felt in the high seas, but the  amplitude enlarges as it approaches the coast. When it reaches the coast, tsunamis sometimes hit land in the form of giant water walls (especially in large tsunamis), but the more common form is a sudden rise in water level.Rising water levels can reach 15-30 meters, cause flooding with current speeds up to 90 km / h, reach several kilometers from the coast, and cause great damage and casualties.

The most common cause of tsunamis is underwater earthquakes, especially those that occur in the subduction zone with a magnitude of 7.0 or more. Other causes are landslides, volcanic eruptions, and the fall of large objects such as meteors into the water. Geographically, almost all tsunamis occurred in the Pacific Ring of Fire and the Sumatran Trench area in the Indian Ocean.Tsunami risk can be detected by a tsunami early warning system that observes large-scale earthquakes and analyzes data on seawater changes that occur afterwards. If there is a tsunami risk, the authorities can give warnings or take actions such as evacuation.
The risk of damage can also be reduced by tsunami resistant designs, such as building buildings with large spaces, and the use of reinforced concrete materials, as well as by counseling the community about how to save themselves from tsunamis, such as the importance of evacuating and preparing contingency plans in advance.

And the impact of the tsunami, namely:
1. There is damage everywhere
2. Agriculture and fisheries are damaged
3. Inhibiting economic activity
4. material loss
5. Spiritual loss
6. Cause disease germs