The waves over the ocean occur at the top layer of the oceans. A wave may travel for more than one thousand kilometers before striking coasts. A wave can be a small ripple or a large tsunami. A lot of momentum and energy is present in waves.
How are waves formed?
The three major factors that cause waves are as follows:
Wind speed, the distance of water over which wind has blown and the amount of time wind has blown above the water surface.
The waves will be larger as each of the listed factors is greater. A wave's height is the distance between its trough and crest. The wavelength is the distance between one crest and the next. The period is the time between two sequential waves from a given point.
There are three types of waves.
Ripples, which are also called capillary waves, appear over smooth waters. When the winds stop blowing, these waves can die out but they can move in forward direction in the presence of good surface tension.
Seas are slightly larger waves formed due to un-sustained and irregular winds. Even after the winds cease blowing, they can last for long.
Swells are waves that form when the sea waters move away from a point of origin, by then separating in different directions and forming different wavelengths.
Tsunami
The word tsunami originated in the Japanese language and means 'harbor waves' with tsu meaning harbor and nami meaning waves. Tsunamis can occur because of underwater earthquakes with a Richter magnitude above 6.75, underwater rock slides, volcano eruptions or when an asteroid crashes into the ocean from space. Tsunamis start when a large water volume gets shifted due to any of the abovementioned phenomena. The resultant wave is huge and may spread across even a hundred miles. The wave can then move from the origin towards the coast at a big speed of hundreds of miles per hour. This is equivalent to jet-speed. Within a few hours, a tsunami can travel very great distances.
With advancing technologies, tsunamis can be discovered before they arrive at the coast. Most of the tsunamis occur in the Pacific. They are rare and only about six of them hit the coasts every century.
Waves & Global Warming
Another factor that can affect wave speeds is global warming. Geophysicists say that as the ocean surfaces warm up, the speed of planetary waves will increase. The speed of such waves has already increased substantially. But this hasn't been noticed until now as the satellites that monitor the oceans are only recent advances in technology. Latest research says that the wave speeds will increase by about 30% within the end of 21st century.
Many people love the seas. The waves and the seas are gifts of nature. Though the waves have indeed caused lot of destruction we need to be alert for warnings and keep away from seas whenever asked to. It is better to keep away from the seas during a high tide, because then the waves will be high and it will be dangerous.
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