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Question: How are topography and bathymetry different? Similar?

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Turn In:-Article Summary-Worksheet 14-6

Properties of Properties of WavesWaves

Anatomy of a WaveAnatomy of a Wave Wave: Wave: a disturbance that a disturbance that

carries energy through matter carries energy through matter or spaceor space

Crest: Crest: the highest point of a the highest point of a wavewave

Trough: Trough: The lowest point in a The lowest point in a wavewave

Wave LengthWave Length wavelength: wavelength:

the distance the distance between any between any two two corresponding corresponding locations on locations on the wave. the wave.

Can be measured Can be measured from: from: crest to next crest to next

crestcrest trough to next trough to next

troughtrough from the middle from the middle

of a wave to the of a wave to the middle of the middle of the next wave. next wave.

AmplitudeAmplitude

The height of the wave from its The height of the wave from its center to either a crest or a troughcenter to either a crest or a trough

Wave PeriodWave Period the amount of time the amount of time

for one wave to for one wave to pass by a certain pass by a certain point.point.

Calculate by Calculate by dividing the dividing the amount of time by amount of time by the number of the number of waves that pass by waves that pass by in that time. in that time.

A surfer knows that A surfer knows that the wave period is the wave period is important to a good important to a good day of surfing. He day of surfing. He watches 20 waves watches 20 waves go by in 200 go by in 200 seconds. What is seconds. What is the period of the the period of the waves?waves?

10 sec/ wave10 sec/ wave

Wave SpeedWave Speed

How fast a wave How fast a wave movesmoves

Remember that Remember that

rate= distance / rate= distance / timetime

For a waveFor a wave distance= distance=

wavelengthwavelength Time= wave periodTime= wave period

Practice:Practice: The wavelength of The wavelength of

an ocean wave is an ocean wave is 10 m and the 10 m and the period of the same period of the same wave is 5 seconds. wave is 5 seconds. What is the wave What is the wave speed?speed?

2 m/s2 m/s

Types of WavesTypes of Waves Ocean wavesOcean waves Sound wavesSound waves Seismic waves Seismic waves

(Earthquake)(Earthquake) Light wavesLight waves

Electromagnetic Electromagnetic spectrumspectrum

Ocean WavesOcean Waves

disturbances of water surfaces disturbances of water surfaces caused by energy from winds, caused by energy from winds, earthquakes, or volcanic explosionsearthquakes, or volcanic explosions

An example of surface waves (waves An example of surface waves (waves forming at the boundary between forming at the boundary between two different materials)two different materials)

Most ocean waves at the beach are Most ocean waves at the beach are created by windcreated by wind

                                                       Breakers (above) crash to the beach in Myrtle Beach, South Carolina.

What actually happens What actually happens when a wave goes by?when a wave goes by?

Ocean waves transfer energy rather than Ocean waves transfer energy rather than actually moving the water along with actually moving the water along with them.them.

When wave energy passes through water, When wave energy passes through water, the water moves in a circular motion.the water moves in a circular motion.

Watch the beach ball in the following Watch the beach ball in the following animation

The beach ball moves in a circle while the The beach ball moves in a circle while the energy of the wave moves from left to energy of the wave moves from left to rightright

What actually happens What actually happens when a wave goes by?when a wave goes by?

The circles that the The circles that the water particles make water particles make get smaller with get smaller with depthdepth

The energy being The energy being transmitted transmitted decreases with depthdecreases with depth

Water particles move Water particles move in a circular pattern in a circular pattern down to a depth of ½ down to a depth of ½ the wavelengththe wavelength

What happens when a What happens when a wave reaches the shore?wave reaches the shore?

Water deeper than ½ the Water deeper than ½ the wavelength wavelength the energy of the wave moves the energy of the wave moves

forwardforward the water stays in place. the water stays in place.

wave approaches shore wave approaches shore depth of the water is less depth of the water is less

than ½ the wavelengththan ½ the wavelength the friction against the ocean the friction against the ocean

floor slows the wave down and floor slows the wave down and shortens its wavelengthshortens its wavelength

The wave breaks and crashes on The wave breaks and crashes on the shore.the shore.