How is a tsunami formed? How a tsunami is formed

Tsunamis are usually caused by the seafloor with an epicenter within 50 km below the seafloor and above the Richter scale. The wavelength of the tsunami is larger than the maximum depth of the ocean, and the propagation near the seabed is not much hindered, regardless of the depth of the ocean, the wave can propagate past, the tsunami propagation speed in the ocean is about 500 to 1,000 kilometers per hour, and the distance between the two adjacent waves may also be as far as 500 to 650 kilometers, when the tsunami wave enters the land shed, due to the shallow depth, the wave height suddenly increases, and the waves rolled up by its wave movement can reach tens of meters high, and form a "water wall".

The fluctuations caused by ** are different from the waves on the sea surface, which only fluctuate in the water layer at a certain depth, while the water fluctuations caused by ** are the ups and downs of the entire water layer from the sea surface to the seabed. In addition, submarine volcanic eruptions, landslides and man-made underwater nuclear explosions can also cause tsunamis. In addition, a meteorite impact can also cause a tsunami, and the "wall of water" can reach up to 100 feet.

And tsunamis caused by meteorites also have a chance to occur in any waters, not necessarily in the ** zone. However, a tsunami caused by meteorites may occur only once in a thousand years.

What is a tsunami, and how is a tsunami formed?

The causes of tsunamis can be divided into three categories: tsunamis, volcanic tsunamis, and landslide tsunamis. A tsunami is a strong disturbance of seawater caused by a sharp rise and fall in the topography of the seabed. There are two forms of mechanism: "descending" tsunamis and "uplifting" tsunamis.

Descending type "tsunami": some tectonic ** causes a large area of sharp decline in the submarine crust, the sea water first swells to the space of sudden staggered subsidence, and there is a large-scale accumulation of seawater above it, when the inrushing seawater encounters resistance on the seabed, it turns back to the sea surface to produce compression waves, forming long waves and large waves, and propagating and spreading around, this descending type of tsunami formed by the movement of the submarine crust is the first to show abnormal low tide phenomenon on the coast. The 1960 Chile** tsunami was of this type.

Uplift "Tsunami": Some tectonic structures ** cause a large-scale sharp rise of the seafloor crust, and the seawater also rises with the uplift area, and there is a large-scale accumulation of seawater above the uplift area, under the action of gravity, the seawater must maintain an equipotential surface to achieve relative equilibrium, so the seawater spreads from the wave source area to the surroundings, forming a turbulent wave. The tsunami waves formed by the movement of the seafloor crust in this uplifted type first appear as an abnormal high tide phenomenon on the coast.

On May 26, 1983, the tsunami caused by the Sea of Central Japan 7 7** was of this type.

Tsunamis can be divided into two categories: remote tsunamis and local tsunamis relative to the disaster site.

Tsunami: A tsunami is a tsunami that crosses an ocean or travels from a great distance, also known as a transoceanic tsunami. Tsunami waves are long-form oceanic waves, and once they are generated at the source, they can generally propagate thousands of kilometers without the blocking of island groups or large shoals and shallow water shelf, so they may cause tsunami disasters thousands of kilometers away.

For example, the tsunami that occurred in Indonesia at the end of 2004 spread thousands of kilometers to Sri Lanka, and the 1960 Chile tsunami also caused serious disasters in Hawaii and Japan, thousands of kilometers away.

Local tsunamis: The majority of tsunamis are local or localized. Because the local tsunami is relatively close to the coastal area from the source of the tsunami to the affected coastal area, the time for the tsunami wave to reach the coast is also shorter, only a few minutes, and sometimes dozens of minutes.

In such cases, tsunami warnings are shorter or non-existent, often resulting in extremely severe disasters.

Tsunamis are formed by strong disturbances in seawater caused by rapid changes in the topography of the seabed.

When the seabed topography rises and falls sharply, the strong disturbance of the seawater will form a tsunami, and the factors that are easy to cause tsunamis are: **, volcanic eruptions, submarine landslides, etc. Tsunamis are divided into "descending" tsunamis and "uplifting" tsunamis according to their movement mechanisms, with "descending" tsunamis being caused by the subsidence of the seafloor crust and "uplifting" tsunami being caused by the uplift of the seafloor crust.

Handicap code. Tsunamis are mainly controlled by the topography of the seabed, the geometry of the coastline and the characteristics of the waves, and the roaring waves and ice walls repeat every few minutes or tens of minutes, destroying the embankments, flooding the land, and taking life and property, which is extremely destructive. The global tsunami occurrence area is roughly the same as the ** zone, and there are about 260 destructive tsunamis recorded worldwide, with an average of about one.

It happens once every six or seven years.

The destructiveness of the tsunami

The speed at which a tsunami travels is directly proportional to the depth of the water in which it travels, and in the Pacific Ocean, the speed of a tsunami is generally between two or three hundred kilometers per hour and more than a thousand kilometers per hour. Tsunamis do not cause damage in the deep oceans, and it is difficult for ships under sail to detect such fluctuations. When a tsunami occurs, the safer it is to the outer sea.

Once a tsunami enters the continental shelf, the wave height increases dramatically to 20 to 30 metres due to a sharp decrease in depth.

Such waves can be devastating. Therefore, the tsunami will also erect a wall of water at the sea level, which also contains great energy, like the waves of death, the ultimate destroyer of the earth, which can destroy everything in an instant, and the tsunami will also bring tons of rocks and boats, and even go upstreams along the river that enters the sea, and the low-lying land will be swallowed up.

The above content refers to Encyclopedia - Tsunami.

Tsunamis are usually caused by ocean floors**, landslides, and volcanic eruptions.

Tsunami is a catastrophic wave, when the epicenter is within 50 kilometers of the seabed and reaches the level of **, some places sink, some places rise, the strong shaking caused by ** makes the sea surface begin to rise and fall violently, thus forming ** waves. **Waves continue to expand and propagate on the surface of the sea, resulting in the formation of a tsunami.

After a shock, the ** wave travels a long distance in an ever-expanding circle on the surface of the sea, just like the wave produced by a pebble falling into a shallow pool. The tsunami wavelength is greater than the maximum depth of the ocean, and the orbital motion is not much hindered near the ocean floor, and the wave can propagate regardless of the depth of the ocean. In addition to the seabed**, landslides or volcanic eruptions can cause tsunamis.

Classification of species:

Descending type "tsunami": some tectonic ** causes a large area of sharp decline in the submarine crust, the sea water first swells to the space of sudden staggered subsidence, and there is a large-scale accumulation of seawater above it, when the inrushing seawater encounters resistance on the seabed, it turns back to the sea surface to produce compression waves, forming long waves and large waves, and propagating and spreading around, this descending type of tsunami formed by the movement of the submarine crust is the first to show abnormal low tide phenomenon on the coast.

Uplift "Tsunami": Some tectonic structures ** cause a large-scale sharp rise of the seafloor crust, and the seawater also rises with the uplift area, and there is a large-scale accumulation of seawater above the uplift area, under the action of gravity, the seawater must maintain an equipotential surface to achieve relative equilibrium, so the seawater spreads from the wave source area to the surroundings, forming a turbulent wave.