page_title: Wind wave
section_title: Types
hierarchical_section_title: Wind wave / Types
caption_attribution_description: English: The waves at Porto Covo, west coast of Portugal. Stitch of four photos. Français&#160;: Des vagues à Porto Covo, côte Ouest du Portugal. Panorama composé de 4 photos.
context_page_description: In fluid dynamics, wind waves, or wind-generated waves, are water surface waves that occur on the free surface of bodies of water. They result from the wind blowing over an area of fluid surface. Waves in the oceans can travel thousands of miles before reaching land. Wind waves on Earth range in size from small ripples, to waves over 100 ft high, being limited by wind speed, duration, affected area and water depth.
  When directly generated and affected by local waters, a wind wave system is called a wind sea. Wind waves will travel in a great circle route after being generated - curving slightly left in the southern hemisphere and slightly right in the northern hemisphere. After moving out of the area of fetch, wind waves are called swells and can travel thousands of miles. A noteworthy example of this are waves generated south of Tasmania during heavy winds that will travel to southern California producing desirable surfing conditions. More generally, a swell consists of wind-generated waves that are not significantly affected by the local wind at that time. They have been generated elsewhere or some time ago. Wind waves in the ocean are called ocean surface waves.
context_section_description: Three different types of wind waves develop over time:
  Capillary waves, or ripples, dominated by surface tension effects.
  Gravity waves, dominated by gravitational and inertial forces.
  Seas, raised locally by the wind.
  Swells, which have travelled away from where they were raised by wind, and have to a greater or lesser extent dispersed.
  Ripples appear on smooth water when the wind blows, but will die quickly if the wind stops. The restoring force that allows them to propagate is surface tension. Sea waves are larger-scale, often irregular motions that form under sustained winds. These waves tend to last much longer, even after the wind has died, and the restoring force that allows them to propagate is gravity. As waves propagate away from their area of origin, they naturally separate into groups of common direction and wavelength. The sets of waves formed in this manner are known as swells.
  Individual "rogue waves" (also called "freak waves", "monster waves", "killer waves", and "king waves") much higher than the other waves in the sea state can occur. In the case of the Draupner wave, its 25 m (82 ft) height was 2.2 times the significant wave height. Such waves are distinct from tides, caused by the Moon and Sun's gravitational pull, tsunamis that are caused by underwater earthquakes or landslides, and waves generated by underwater explosions or the fall of meteorites—all having far longer wavelengths than wind waves.
  The largest ever recorded wind waves are not rogue waves, but standard waves in extreme sea states. For example, 29.1 m (95 ft) high waves were recorded on the RRS Discovery in a sea with 18.5 m (61 ft) significant wave height, so the highest wave was only 1.6 times the significant wave height.
  The biggest recorded by a buoy (as of 2011) was 32.3 m (106 ft) high during the 2007 typhoon Krosa near Taiwan.
caption: Surf on a rocky irregular bottom. Porto Covo, west coast of Portugal
exif: {}