Q:

What is the fetch of a wave?

A:

Quick Answer

Fetch is the distance that wind has traveled over open water without encountering an obstruction. In normal circumstances, long fetches create larger, more powerful waves than short fetches.

Know More

Full Answer

As wind travels over water, it pushes the surface of the water in the same direction, creating waves. Because smaller waves travel faster than larger waves, the smaller waves overtake and merge with the larger waves. This causes the larger waves to gain in height, so more water is exposed to the wind. This causes more friction and gives the wave more energy. The longer the fetch, the more times this process repeats until the wave crashes against an object, such as a beach, and depletes its energy.

Both the speed and direction of the wind are important in estimating the size of waves along a fetch. Constant, high-speed wind along a long fetch creates the largest waves. For example, Land's End, Cornwall, along the south-western coast of Britain, is at the receiving end of a fetch originating from near the South American coast. This area routinely sees very large waves. The British town of Dover, in Kent, has a much smaller fetch. Although fetch is an important determination of wave size, extreme winds can cause high waves even along short fetches.

Learn more about Tides

Related Questions

  • Q:

    How does a tidal barrage work?

    A:

    Electricity is generated through the revolution of turbines installed in a dam built across a river. Turbines are designed to work for both the ebb and the flow directions. These turbines move due to tidal movements.

    Full Answer >
    Filed Under:
  • Q:

    How do waves work?

    A:

    When the sun heats the air, it causes the air to become lighter and float upwards. When hot air floats upwards, cooler air rushes in to take its place. The rush of the cool air against the water creates ripples, which eventually turn into waves.

    Full Answer >
    Filed Under:
  • Q:

    How do the tides work?

    A:

    According to the National Oceanic and Atmospheric Administration, the tides are caused by the gravitational force that pulls on the water and the forces exerted by the moon and the sun. The gravitational pull of the moon cause the ocean to bulge out in its direction, while another bulge occurs on the opposite side of the earth.

    Full Answer >
    Filed Under:
  • Q:

    Why do waves break?

    A:

    Waves break when the back of the wave moves faster than the front of the wave, causing it to spill over. The shape of a breaking wave is dictated by the shape of the ocean floor below it, with gentle slopes causing a gentle spill on a cresting wave.

    Full Answer >
    Filed Under:

Explore