What causes tides? What causes the tides

Tides are caused by the Earth-Moon attraction. The Earth-Moon attraction causes periodic movements and changes in the Earth's lithosphere, hydrosphere, and atmosphere, known as "tides", which are divided into geotidal, oceanic, and atmospheric tides.

The vast majority of water is seawater, and the gravitational pull of the sun and the moon will rise and fall, because the earth and the moon are constantly moving, the relative position of the earth, the moon and the sun is changing periodically, so the gravitational force is also changing periodically.

Water also rotates with the rotation of the earth, and the rotating objects are subjected to a force. In ancient times, the water gushing in the river during the day was called the tide, and the tide at night was called the tide, and it was customary to call the vertical rise and fall of the sea surface as the tide, which is a natural phenomenon in the coastal area.

The tides are made up of the moon.

caused by the attraction.

Tides are the periodic rise and fall of sea water. Because the day is the morning and the night is the night, the rise and fall of the sea during the day is called "tide", and the rise and fall of the sea water that occurs at night is called "tide".

Rising tide. of the conditions for its formation.

The law of gravitation.

Shows that the magnitude of the gravitational force is directly proportional to the product of the masses of the two objects and inversely proportional to the square of the distance between them. The gravitational pull of the Sun on the Earth is much stronger than the gravitational pull of the Moon on the Earth, but the gravitational pull of the Sun is less than that of the Moon1 2. What's going on?

It turns out that the gravitational force (or tidal force) that causes the rise and fall of sea water, although it is caused by the gravitational pull of the sun and the moon, is not the absolute gravitational force of the sun and the moon, but the difference between the gravitational force of the attracted object and the gravitational force of the center of the earth. The gravitational force is directly proportional to the mass of the tidal object and inversely proportional to the cube of the distance from the object to the Earth. Because the mass of the Sun is 2710x104 times that of the Moon, and the average distance between the Sun and the Earth is 389 times the average distance between the Moon and the Earth, the gravitational force of the Moon is twice that of the Sun, thus mechanically proving that the tides are indeed mainly caused by the Moon.

For example, if the tide is 10 meters high at its highest, and almost 7 meters is caused by the Moon, the contribution of the Sun is only 3 meters, and the other planets are less than millimeters.

Tides are caused by gravitational action.

Tidal phenomenon is the fluctuation of the earth's seawater by the gravitational attraction of the moon and the sun (less effective), because the moon revolves around the earth, the earth's oceans are pulled by the moon's gravity, and there is a high lake on the other side of the moon, and at the same time, another high lake appears on the other side of the earth away from the moon.

This is because the Moon's gravitational pull on the Earth itself is greater than its effect on its water bodies, causing the sea water on the other side to be outward"drums". Tides are not only affected by the gravitational pull of the Moon and the Sun, but are also influenced by the natural geography of the region.

Therefore, the tides vary from place to place, and different regions often have different tidal systems, which all derive energy from deep-sea tide waves, but have their own unique characteristics.

What is tidal energy?

Tidal energy: The energy possessed in the periodic ebb and flow movement of seawater. Its water level difference is expressed as potential energy, and the speed of its current flow is expressed as kinetic energy. Both of these energies can be utilized and are a renewable source of energy.

Because the tide is the most trustworthy and regular in the various movements of the seawater, and rises and falls on the shore, it is also the first to be recognized and utilized by people, and the utilization of tidal energy is the most mature in the utilization of various marine energy.

Tidal power generation is similar to the principle of ordinary hydroelectric power generation, which carries the seawater out of the reservoir through the reservoir, stores the seawater in the reservoir at high tide, and saves it in the form of cautious potential energy, and then releases the seawater at low tide, and uses the difference between high and low tide levels to drive the turbine to rotate and drive the generator to generate electricity.

Tides are a natural phenomenon. The ebb and flow of the tide is caused by the combined action of the gravitational forces of the Moon and the Sun and the centrifugal force generated by the rotation of the Earth. Every year on the spring and autumn equinoxes, the earth, the sun and the moon are almost in a straight line, and the moon and the sun have a particularly strong attraction force on the seawater, and the sea water rises extremely high and falls the lowest.

In addition to the above reasons, the Qiantang River tide is so spectacular, but also due to the specific geographical situation and meteorological and hydrological conditions of the Qiantang River estuary. The entrance to the sea of the Qiantang River estuary is Hangzhou Bay, it is a typical horn estuary in the topography, the closer to the East China Sea, the wider it is, the widest point reaches 100 kilometers, starting from the Nanhui mouth of the Hangzhou Bay estuary, it shrinks sharply to the west, it is narrow to 30 kilometers near Luopu, and it is only 3 kilometers to the river surface of Haining Yanguan. The mouth of the river is wide, and the tide rushes in in large quantities, and when it goes in, the river suddenly narrows, and the water flow is not smooth, and the tides must be stacked on top of each other.

The water level is elevated. In addition, at the bottom of the riverbed near the Qiantang River, there is a north-south sand ridge, which acts like a threshold and plays the role of further raising the water level.