emwave.gifBasic Info. ; A wave is a disturbance that goes through space and time with energy. We are going to tell you about waves in the water. Water waves are a type of mechanical wave. Mechanical waves are waves that go through a material medium, or a solid, liquid, or a gas. To measure a wave you can measure it's highest point or it's crest. Next, the lowest point a wave reaches is the trough. The distance from the crest of one wave to the crest of the next is the wave-length. Also, the number of waves that pass a given point in one second is called the wave's frequency. Also, the still water level is the level at which the water would be without the wave or the ripples. And last, the wave period measures the size of the wave in time.

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The crest, trough and wavelength of waves
The crest, trough and wavelength of waves

Fetch is the distance over which the wind interacts with the water to create waves. Waves move by the small movements of the water molecules in the water. When the wind blows over the water, it changes the surface into ripples and small and large waves.

Waves in shallow water: As waves enter shallow water, they become taller and they slow down and they eventually come upon the shore.

Waves in deep water: Waves are classified as deep water waves if their depth is greater than it's wavelength. In deep water, waves are the forward motion of energy not water. Matter of fact, if you were to follow one drop of water while waves were moving in deep water, you would see it just rotates around and around. As depth increases, their effects slowly drop until disappearing about half way below the wavelenght.

Wave reflection is when waves bounce off of something denser like rocks. They can also bounce off of sandy shores.


This picture is a picture of a tidal wave in the ocean.

A wave's size depends on, how fast and how long the wind is blowing that created the wave. For example, a small and gentle wind creates not big waves, but small ripples in the water, and a long, strong, steady wind would create larger more powerful waves.
Tsunamis are one type of wave that is not created by the wind. A Tsunami, the Japanese word for "harbor wave," is created by to many waves passing in one frequency, or also by vibrations or earthquakes under the water. They are classified as shallow water waves with long wavelengths. For example, in the Pacific Ocean, the depth is about 4000m and a tsunami travels at 200m/s. Not only do they travel quickly, they also can go long distances with barely using up any of their energy.

This is a picture of a tsunami.
waves.jpgVibrations are classified as a back and forth motion that goes around a point. Reflection is wave direction change when hitting a reflective surface. Dispersion is a wave splitting up by frequency. Diffraction is a wave circular spreading from entering a hole of comparable size to their wavelengths.

Types of waves: There are many types of waves and these are a few.Surging breakers, Plunging breakers, and Spilling breakers. Surging breakers are waves that happen on beaches when the slope is very steep. Plunging breakers are waves that happen on beaches when the slpoe is moderatly steep. And last, spilling breakers are waves that occur on beahes and that have gentle slopes.

TIDES: An ocean tide refers to the constant rise and fall of seawater. Tides are caused by variations in gravitational attraction between earth and the moon. The moon somewhat controls the rythm and heights of the tides. The moon makes 2 tidal bulges on earth because of the effects of gravitational attraction. The moon's gravitational force and the earth's gravity pulling the water back to earth controls the height of the tidal bulges. The place on earth that is closest to the moon, seawater is pulled to the moon because of the greater strength of gravitational attraction. On the other side of earth, another tidal bulge is made away from the moon. Beacause of this, any place on earth's surface can have 2 tidal crests and 2 tidal troughs during every tidal period. There are five of tidal waves, Semidiurnal tides, Diurnal tides, Neap tides, Spring tides, and Mixed tides.

Waves can be made in many different ways including by movement under the water or by rocking ships and boats, but most of the time, waves are made by the wind, either strong or gentle. Wind makes waves on the surface of oceans and lakes. The wind adds some of it's energy to the water through resistance between the air molecules and the water molecules. Strong winds make large waves. Waves don't travel horizontally they move up and down. When the wave breaks, the violence of that wave is determined by how stepp the seabed is in which it is now entering.

This picture is a plot of the waves' heights and the wind speeds. This was created on board the NDBC buoy station 51001.