Why is there a tsunami at sea?

Tsunami is a kind of water movement with great energy, and the damage caused is also appalling.

The Indian Ocean tsunami in 2004 was one of the deadliest natural disasters in history, with more than 200,000 people killed in South Asia. In the 20 1 1 earthquake in Fukushima, Japan, the tsunami crossed the flood wall protecting the Fukushima nuclear power plant in Japan, causing a nuclear disaster, causing more than18,000 deaths. Therefore, when the tsunami comes, Conan's situation will change color.

Tsunami is also called tidal wave, but it has little to do with the tides caused by the sun and moon that we are familiar with.

In many cases, tsunami is just a wave bigger than ordinary waves. They have valleys and peaks, but they are not that kind of running water, but an energy movement of water.

The key to distinguish tsunami from ordinary waves is where this energy comes from.

Normal waves come from the wind. Because the wind only affects the water surface, the size and speed of waves are limited.

But tsunamis are caused by underwater energy, such as volcanic eruptions? Submarine landslide? Or the most common undersea earthquake is caused by plate sliding on the earth's surface. These geological movements released a lot of energy into the water. When this energy propagates upward to the surface of the water body, it will lift the water to make the water surface higher than the normal sea level, but gravity will pull it down, thus forming waves with energy propagating laterally outward.

As a result, the tsunami appeared and traveled on the sea at a speed of 150 kilometers per hour.

When the tsunami is far away from the coast, it is hardly noticed, because the depth of the deep sea is several kilometers, and the waves caused by the tsunami are not conspicuous.

However, when the tsunami reached the shallow water area, this huge energy was compressed due to the reduction of water bodies. The speed of the waves is very slow, but the height can rise to 30 meters!

The word tsunami is written as "tsunami" in Japanese, which means huge waves that appear near the coast.

If the bottom of the tsunami reaches the coast first, the sea will be farther away from the coast than normal before the waves hit.

This situation is both dangerous and misleading.

When Persian soldiers besieged the Greek city of Portia in 479 BC, they found that the tide receded further than usual, leaving a convenient attack route. But they were cheated. Before the soldiers got halfway, a water wall several tens of meters high came and drowned the attacker. The Tedians thought they were saved from Poseidon's anger. But what really saved them was the tsunami.

After the sea receded, the peak came. Huge waves will not only flood people near the coast, but also destroy all buildings and trees 500 meters or more inland. In addition to the first wave of impact, in the process of returning, the sea will sweep everything on the road again, causing huge casualties.

At present, there is no good way for human beings to fight against the super-natural energy release of tsunami. Hope can only be pinned on early detection and early warning.

People have released a large number of sensors in the ocean to monitor underwater pressure and seismic activity, and established a global communication network to send alarms quickly.

Even at the current level of human science and technology, facing nature is still so small and helpless, so when the tsunami strikes and you are unfortunately at the seaside, there is only one solution: escape!