2. Ocean Waves
What are the characteristics of ocean waves and what causes their formation?
Waves are beats of energy moving through the ocean, caused by wind, earthquakes and the gravitational pull of the moon. Out of all those, wind's the most common for forming waves. Wind transfers energy to the water and that causes the water to move. Well, at least thats what you think. When you observe waves, it looks as if the water is moving forward, when in fact it's only the energy thats moving through the wave. The particles of water are all lined up, and the energy is transferred from one water particle to another (the energy is passed downward) and the particles stay in the same general spot. When people go to the beach, they usually tend to stay toward the shore because they think that the waves will be smaller, but in fact they are bigger. The deeper it is, the slower the waves are. Underwater, there are no waves caused by energy. The only time you will find a wave underwater is if it is caused by a tide or an earthquake.
I'm sure you've notice that ocean waves have different heights. These heights depend on the wind's speed, the amount of water it blows over, and how long it blows over the water. The higher each of the things are, the higher the wave it creates. The following are some examples.
Waves are beats of energy moving through the ocean, caused by wind, earthquakes and the gravitational pull of the moon. Out of all those, wind's the most common for forming waves. Wind transfers energy to the water and that causes the water to move. Well, at least thats what you think. When you observe waves, it looks as if the water is moving forward, when in fact it's only the energy thats moving through the wave. The particles of water are all lined up, and the energy is transferred from one water particle to another (the energy is passed downward) and the particles stay in the same general spot. When people go to the beach, they usually tend to stay toward the shore because they think that the waves will be smaller, but in fact they are bigger. The deeper it is, the slower the waves are. Underwater, there are no waves caused by energy. The only time you will find a wave underwater is if it is caused by a tide or an earthquake.
I'm sure you've notice that ocean waves have different heights. These heights depend on the wind's speed, the amount of water it blows over, and how long it blows over the water. The higher each of the things are, the higher the wave it creates. The following are some examples.
Wind Speed-(miles per second)5.1
|
How long wind blows-(hours)2.4
|
Distance wind touches-(km)18.5
|
Hight of wave-(meters)0.27
|
10.2
15.3
20.4 25.5 |
10.0
23.0
42.0 69.0 |
140.0
520.0
1320.0 2570.0 |
1.5
4.1
8.5 14.8 |
Much like energy waves and light waves, ocean waves have different characteristics. The very top of the wave is the crest, and the very bottom is the trough. The distance from side to side/horizontal is the wavelength and the distance between top and bottom/crest and trough is the height.
A wave period is the amount of time it takes a trough or crest to pass a certain point. Relating to this is the wave frequency and that is the number of crests or troughs in a certain amount of time. Wavelengths are usually pretty constant, meaning they're almost always the same distance apart. Waves like that are considered swells, and aren't very high, just consistent, long and wide. When swells reach the shore, or close to it, they slow down and come closer together. The wavelength becomes less and the hight becomes greater. When they crash into the shore, they break and become whats known as surfs. The following is an example of that process.
By now your probably asking what happens to the water after it breaks away and becomes a surf. Well, it simply folds under and goes back into the ocean. This is known as the undertow, and they are sometimes strong and they can become very dangerous. The following is an example.
Dangerous waves-
I'm sure you've heard of a tsunami, but you may not understand it completely. A tsunami is formed by an earthquake, and they are very dangerous. These are the highest ocean waves after they reach the shore. These have particularly long wavelengths and are especially deep. Tsunami's are also like other waves and they still get higher towards the shore. This is very dangerous because tsunami waves have a lot of energy and power and when they slow down, they have less wave to distribute that power to. Tsunamis are very tall and usually reach to about 35 meters (10 stories or more).
So, as you can tell, some waves are harmless while others are extremely harmful. Waves in general are complicated, but if you have the right ones, they are very fun to play in!