Properties of Waves

Anatomy of a WaveWave: a disturbance that carries

energy through matter or spaceCrest: the highest point of a waveTrough: The lowest point in a wave

Wave Lengthwavelength: the distance between any two corresponding locations on the wave.

Can be measured from: crest to next

cresttrough to next

troughfrom the middle

of a wave to the middle of the next wave.

AmplitudeThe height of the wave from its center to

either a crest or a trough

Wave Periodthe amount of time

for one wave to pass by a certain point.

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

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

10 sec/ wave

Wave SpeedHow fast a wave

movesRemember that

rate= distance / timeFor a wave

distance= wavelength

Time= wave period

Practice:The wavelength of

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

2 m/s

Types of WavesOcean wavesSound wavesSeismic waves

(Earthquake)Light waves

Electromagnetic spectrum

Ocean Wavesdisturbances of water surfaces caused by

energy from winds, earthquakes, or volcanic explosions

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

Most ocean waves at the beach are created by wind

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

What actually happens when a wave goes by?Ocean waves transfer energy rather than

actually moving the water along with them.When wave energy passes through water, the

water moves in a circular motion.Watch the beach ball in the following

animationThe beach ball moves in a circle while the

energy of the wave moves from left to right

What actually happens when a wave goes by?

The circles that the water particles make get smaller with depth

The energy being transmitted decreases with depth

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

What happens when a wave reaches the shore?Water deeper than ½ the wavelength

the energy of the wave moves forwardthe water stays in place.

Wave approaches shore depth of the water is less

than ½ the wavelengththe friction against the ocean floor slows

the wave down and shortens its wavelengthThe wave breaks and crashes on the shore.

Mavericks Big Waves

Mavericks QoD: 1/30How big are the waves at Mavericks?

Are they dangerous?

What causes the waves to get so incredibly big?

Why do big waves happen here?Waves start in the North Pacific during

winter storms

If the wind is blowing hard enough in the North Pacific, the waves will have a

large amount of energy when they

reach California

Bathymetry of MavericksMavericks is in

the box

Seafloor mapping shows blue as deepest

BathymetryAs waves approach

Pillar Point, the center of the wave hits shallow water before the sides

The wave slows down in the center, but not the sides

Because the wave speed is different in the center than the sides, the wave becomes curved

The wave height in the center becomes much larger than the sides because the seafloor is shallower there

Mavericks

Did you turn in your Article???Reasons not to procrastinate…

Technical issuesTechnical FAILURESYou might get sickYou might forgetYou might run out of timeYour dog might eat your assignment instructions,

and then you find out that the article you found got lost in your email, and then on top of that your brother needs help doing his homework, and you have to do a make-up test for Math, and…

Sourceshttp://secoora.org/classroom/waves/fact-

sheet/http://www.pwssc.org/education/media/http://geoinfo.amu.edu.pl/wpk/pe/a/

harbbook/c_vi/chap06.html