Why waves form. Formation of sea waves – World of Knowledge
Waves are created by the wind. Storms create winds that affect the surface of the water, causing ripples. Just like the ripples in your cup of coffee after surfing when you blow on it. The wind itself can be seen on weather forecast maps: these are low pressure zones. The greater their concentration, the stronger the wind will be. Small (capillary) waves initially move in the direction the wind is blowing. The stronger and longer the wind blows, the greater its effect on the surface of the water. Over time, the waves begin to increase in size. As the wind continues to blow and the waves generated by it continue to be affected by it, small waves begin to grow. The wind has a greater effect on them than on a calm surface of the water. The size of a wave depends on the speed of the wind that forms it. Wind blowing at some constant speed will be able to generate a wave of a certain size. And as soon as the wave acquires the maximum possible dimensions at this wind, it becomes "fully formed". The generated waves have different wave speeds and periods. (See wave terminology for more details.) Long period waves travel faster and travel longer distances than their slower counterparts. As they move away from the source of the wind (spread), the waves form lines of surfs (swells), which inevitably roll onto the shore. You are probably already familiar with the concept of "wave set" (wave set)! Waves that are no longer affected by the wind that generated them are called bottom waves (groundswell). This is exactly what surfers are looking for! What affects the size of the surf (swell)? There are three main factors that affect the size of waves on the high seas: Wind speed - the higher it is, the larger the wave will be. The duration of the wind is similar to the previous one. Fetch (fetch, “coverage area”) - again, than more area coverage, the larger the wave is formed. As soon as the influence of the wind on them stops, the waves begin to lose their energy. They will move until the moment when the protrusions of the seabed, or other obstacles in their path (a large island for example) absorb all the energy. There are several factors that affect the size of a wave at a particular location in the surf. Among them: The direction of the surf (swell) - will it allow us to get the swell to the place we need? The ocean floor is a swell moving from the depths of the ocean to the reef, forming large waves with barrels inside. A shallow long ledge stretching towards the shore will slow down the waves and they will lose their energy. Tides - some sports are completely dependent on it. Find out more in the section on how the best waves appear.
Initially, the wave appears due to the wind. A storm formed in the open ocean, far from the coast, will create winds that will begin to affect the surface of the water, in connection with this, a swell begins to occur. Wind, its direction, as well as speed, all these data can be seen on weather forecast maps. The wind begins to inflate the water, and "Small" (capillary) waves will begin to appear, initially they begin to move in the direction in which the wind blows.
The wind blows on a flat water surface, the longer and stronger the wind starts to blow, the greater the impact on the water surface. Over time, the waves merge and the size of the wave begins to increase. The constant wind begins to form a large swell. The wind has a much greater effect on the already created waves, although not large - much more than on the calm expanse of water.
The size of the waves directly depends on the speed of the blowing wind that forms them. A wind blowing at a constant speed can generate a wave of comparable size. And as soon as the wave acquires the size that the wind put into it, it becomes a fully formed wave that goes towards the coast.
Waves have different speeds and periods. Waves with a long period move fast enough and cover greater distances than their counterparts with a lower speed. As you move away from the source of the wind, the waves combine to form a swell that goes towards the coast. Waves that are no longer affected by the wind are called "Bottom Waves". These are the waves that all surfers hunt for.
What affects the size of a swell? There are three factors that affect the size of waves in the open ocean:
Wind speed - The higher the speed, the larger the wave will eventually be.
Wind duration - the longer the wind blows, similarly to the previous factor, the wave will be larger.
Fetch (wind coverage area) - The larger the coverage area, the larger the wave.
When the effect of the wind on the waves stops, they begin to lose their energy. They will continue to move until such time as they hit the ledges of the bottom of some large oceanic island and the surfer catches one of these waves in case of good luck.
There are factors that affect the size of the waves in a particular location. Among them:
The direction of the swell is what will allow the waves to come to the place we need.
Ocean floor - Swell moving from the open ocean bumps into an underwater ridge of rocks, or a reef - forms large waves with which they can twist into a pipe. Or a shallow ledge of the bottom - on the contrary, it will slow down the waves and they will spend part of their energy.
The tidal cycle - many surf spots are directly dependent on this phenomenon.
The main reason for the formation of waves is the wind blowing over the water. Therefore, the magnitude of the wave depends on the strength and time of its impact. Due to the wind, water particles rise up, sometimes breaking away from the surface, but after some time, under the influence of natural gravity, they inevitably fall down. From afar, it may seem that the wave is moving forward, but in fact, if this wave, of course, is not a tsunami, (tsunamis have a different nature of occurrence), it only descends and rises. So, for example, a sea bird that has landed on the surface of a rough sea will sway on the waves, but will not budge.
Only near the shore, where it is no longer deep, the water moves forward, rolling onto the shore. By the way, according to the scallop of spray from the detached drops forming a crest on the wave, experienced sailors determine the degree of sea disturbance, if the crest and foam on it have just begun to form, then the sea is 3 points.
What kind of sea wave is called a coast.
Waves on the sea can exist without wind, this is a tsunami caused by natural disasters like underwater volcanic eruptions, and a wave that sailors call a coast. It is formed at sea after a strong storm, when the wind died down, but due to the large mass of water that came into motion from the wind and a phenomenon called resonance, the waves continue to sway. It should be noted that such waves are not much safer than a storm and can easily capsize a ship or boat with inexperienced sailors.