What are the signs before a tsunami comes?

Tsunami precursors refer to the signs before a tsunami occurs or lands. Before the tsunami caused by the earthquake lands, there will be some very obvious macro precursor phenomena, which can be discovered by people who live, work and travel by the sea as long as they pay a little attention.

There are roughly four common macro-precursor phenomena of tsunami landing:

1. Abnormal recession or surge of sea water;

2. In the far shallow sea area, the sea surface suddenly turned white, and a long bright wall of water appeared in front of it;

3. The ship in the shallow sea area suddenly bumped violently up and down;

4, is an abnormally loud noise suddenly coming from the sea, which is especially alarming at night.

Others include a large number of fish, shrimps and other marine life appearing in the shallows; the sea water bubbles and suddenly begins to retreat rapidly.

A tsunami is a destructive wave produced by submarine earthquakes, volcanic eruptions, submarine landslides or meteorological changes. The wave speed of a tsunami is as high as 700 to 800 kilometers per hour, and it can cross the ocean within a few hours; wavelength It can reach hundreds of kilometers and can propagate thousands of kilometers with very little energy loss; in the vast ocean, the wave height is less than one meter, but when it reaches the shallow water area of ??the coast, the wavelength is shortened and the wave height increases sharply, up to tens of meters, forming A "water wall" containing huge energy.

Tsunami is mainly controlled by the submarine topography, coastline geometry and wave characteristics. The roaring waves and ice walls repeat every few minutes or tens of minutes, destroying the embankments, flooding the land, and taking away lives and property. Extremely destructive. Tsunami-generating areas around the world roughly coincide with earthquake zones.