The Story Of The Story Of WavesWaves

Waves On The BeachWaves On The Beach

•Most of the Most of the waves we waves we see are at see are at the beach.the beach.

Waves On The BeachWaves On The Beach

•As the wave As the wave travels in travels in shallower shallower water it slows water it slows and eventually and eventually falls forward falls forward as a breaker.as a breaker.

Wind or Storm WavesWind or Storm Waves

•The most The most familiar familiar waves are waves are wind wind generated.generated.

Wind or Storm WavesWind or Storm Waves

•Three things Three things determine determine how large how large these waves these waves can become.can become.

1. Wind Speed1. Wind Speed

•This is the speed that the This is the speed that the wind is blowing.wind is blowing.

•This is usually measured in This is usually measured in knots or nautical miles per knots or nautical miles per hour.hour.

2. Duration2. Duration

•Duration refers to the time Duration refers to the time over which the wind blows.over which the wind blows.

•Winds in some areas may Winds in some areas may blow strong for long blow strong for long periods of time which can periods of time which can produce large waves.produce large waves.

3. Fetch3. Fetch

•Fetch refers to the distance Fetch refers to the distance over which the wind blows.over which the wind blows.

•If a wind blows over If a wind blows over thousands of miles the waves thousands of miles the waves can get much larger than can get much larger than blowing across a small pond.blowing across a small pond.

TidesTides

•Tides are Tides are caused caused mainly by the mainly by the gravitational gravitational pull of the pull of the moon.moon.

Other Things That Other Things That Influence TidesInfluence Tides

•The gravitational The gravitational pull of the sun.pull of the sun.

•The distance of The distance of the sun and the the sun and the moon from earth.moon from earth.

•Winds and other Winds and other factors.factors.

•Tides tend to be high where Tides tend to be high where the gravitational force the gravitational force between the earth and the between the earth and the moon are the strongest, along moon are the strongest, along with the opposite side of the with the opposite side of the earth where the centrifugal earth where the centrifugal force is strongest.force is strongest.

Tidal RangeTidal Range

Spring TidesSpring Tides•Tides have the greatest Tides have the greatest range during spring tides.range during spring tides.•This occurs during the This occurs during the

new and full moons.new and full moons.

Tidal RangeTidal Range

Neap TidesNeap Tides•Tides have the least Tides have the least amount of range during amount of range during

neap tides.neap tides.•This occurs during the first This occurs during the first

and third quarters.and third quarters.

TsunamisTsunamis

•Tsunamis were Tsunamis were once called once called Tidal waves, Tidal waves, but they have but they have nothing to do nothing to do with the tides.with the tides.

TsunamisTsunamis

•They are They are produced by produced by earthquakes and earthquakes and other seismic other seismic disturbances. disturbances. That’s why That’s why they’re also they’re also called called seismic seismic sea waves.sea waves.

Tsunamis are very long, Tsunamis are very long, fast moving waves!fast moving waves!

•They can They can have have wavelengths wavelengths of 150 miles.of 150 miles.

Tsunamis are very long, Tsunamis are very long, fast moving waves!fast moving waves!

•They can They can travel at over travel at over 450 miles per 450 miles per hour! As fast hour! As fast as a jet!as a jet!

The Danger of The Danger of TsunamisTsunamis

•In the open In the open ocean, a ocean, a tsunami may tsunami may only have a only have a wave height wave height of a few feet.of a few feet.

The Danger of The Danger of TsunamisTsunamis

•As the wave As the wave approaches approaches shallow water, it shallow water, it builds to builds to heights that can heights that can reach greater reach greater than 100 feet.than 100 feet.