WAVES
There are two types of wave motion: Longitudinal and traverse waves .In longitudinal waves, the particles are parallel to the direction of wave propagation. In traverse waves, the particles are perpendicular to the direction of wave motion. Further more, in the longitudinal waves, the particles move back and forth about their mean positions. In traverse waves, the particles oscillate up and down about their equilibrium positions.
The water waves are a combination of both the longitudinal waves and traverse waves. While the waves move forward (because of longitudinal properties) the particles rotates in a clockwise motion giving the impression of waves as we see them at oceans.
Energy is required to disturb the particles and make them move in any of above ways. However, the question that arises is, from where do the ocean waves get their energy? They are incessantly moving in the direction predicted without any visible source of energy in sight. The answer is winds. At first, the winds touch the surface of water making the "first waves." Then, after coming in full contact with the surface; they cause "small ripples" to be made. The longer and harder the winds blow, the larger ripples are formed and we can see the full waves moving ahead.
One of most heated topics today is Tsunami and how it is created. Usually tsunami is a result of two kinds of waves, seismic and water waves. Underwater earthquake is the most common cause of tsunami. Volcanic eruptions, landslides and impact of meteorites can also displace large amount of water, generating tsunami. As the seabed is disturbed, large waves are formed as water moves under the impact of gravity to regain its mean position. Because seismic waves cause the entire depth of water to move, wave gain a lot of energy to move at very high speed to very long distances long after the original seismic waves are over, causing immense damage, in form of loss of property and human lives.
