What Causes Waves?What Causes Waves?

WindWindSubmarine disturbanceSubmarine disturbanceGravitational attraction of sun and Gravitational attraction of sun and

moonmoon

Wind Generation of WavesWind Generation of WavesWind velocityWind velocityWind durationWind durationFetch (distance over which wind blows)Fetch (distance over which wind blows)Simply put, wave size Simply put, wave size increasesincreases as all as all

these factors these factors increaseincrease..

Wave MotionsWave Motions ForwardForward movement of the wave form. movement of the wave form. OrbitalOrbital motion of water particles motion of water particles beneathbeneath

the wave.the wave. It is It is wave energywave energy,, NOT water molecules, NOT water molecules,

that moves across the sea surface.that moves across the sea surface.

Deep Water WavesDeep Water Waves

Waves do NOT interact with the seafloor. Waves do NOT interact with the seafloor.

Orbits of the water molecules are Orbits of the water molecules are circularcircular..

Shallow Water WavesShallow Water Waves

Waves DO interact with the seafloor.Waves DO interact with the seafloor.

Orbits of the water molecules become Orbits of the water molecules become ellipticalelliptical..

Rogue Waves?Rogue Waves?

Constructive wave Constructive wave interference - interference - wave wave buildupbuildup

Rogue WavesRogue Waves

http://bit.ly/cs1I9b http://bit.ly/9XWFZu http://bit.ly/dmFsI7

Shallow Waves Affected by Shallow Waves Affected by BottomBottom

In shallow water, the sea bottom In shallow water, the sea bottom transforms the wave’s properties. transforms the wave’s properties. This leads to This leads to wave refractionwave refraction and and waves collapse forming waves collapse forming surfsurf (breakers).(breakers).

Transformation of Shallow-water WavesTransformation of Shallow-water Waves

Motion of Water Particles Beneath Motion of Water Particles Beneath WavesWaves

Wave VideosReflection off a sea wall: http://www.youtube.com/watch?v=PevRZAxDxZwBig wave at beach: http://www.weather.com/blog/weather/8_21326.htmlhttps://www.youtube.com/watch?v=QdoTdG_VNV4&feature=player_embedded#at=131Tacoma narrows bridge: http://video.search.yahoo.com/search/video;_ylt=A2KLqIGXaSdPEn0AIxT7w8QF?p=tacoma+narrows+bridge&b=21&tnr=20