Презентація по слайдам:
There are various natural disasters in the world and tsunami is one of them. Some people call it a tidal wave or a seismic sea wave.
The main reason of tsunami is a submarine earthquake, when there is an underwater landslide. However, the volcanic eruptions can also cause it.
Some countries and regions are especially prone to this disaster, for example, China, Japan, Chile, Sri Lanka, Thailand, Philippines. The biggest tsunami in the history took place in 1958 at Alaskan Lituya Bay. The force of wave then reached 1720 feet above sea level.
Normally, ocean tsunamis reach heights of over 100 feet. Even the mildest walls of water can cause widespread destruction. Another notable tsunami took place on the Indonesian island of Sumatra in December, 2004.
A strong earthquake displaced the ocean floor off the island. More than 200, 000 people were killed within a few hours. For better understanding of tsunami, we should know what the earthquake is. Dozens of tectonic plates support the earth.
These large floating pieces are constantly moving. The earthquake happens when two plates become stuck. Unfortunately, nothing can be done to prevent tsunami, except monitoring minor weather and geological changes.
Scientists work hard to understand where and how the future tsunamis develop. They also record the size and the frequency of previous tsunamis to make all the necessary calculations.
Today, the best way to fight this disaster is to understand the ocean floor structure and to learn the tsunami data. For civil people, the best way of defense is early warning that allows them to find the shelter on higher ground.