Bell work Imagine you are floating in the ocean 1 km from shore, which is north of you. There is a surface current flowing east. Are you more likely to.

Bell workBell work

• Imagine you are floating in the ocean 1 Imagine you are floating in the ocean 1 km from shore, which is north of you. km from shore, which is north of you. There is a surface current flowing east. There is a surface current flowing east. Are you more likely to travel north with Are you more likely to travel north with the waves toward the shore or east the waves toward the shore or east with the surface current? Draw a with the surface current? Draw a diagram to illustrate your answer, and diagram to illustrate your answer, and record your explanation in your record your explanation in your science journal.science journal.

Ocean WavesOcean Waves

How would you describe a How would you describe a wave?wave?

Objectives

• IdentifyIdentify the parts of a wave. the parts of a wave.

• ExplainExplain how the parts of a wave relate how the parts of a wave relate to wave movement.to wave movement.

• DescribeDescribe how ocean waves form and how ocean waves form and move.move.

• ClassifyClassify types of waves. types of waves.

WavesWaves

•A A WaveWave is a is a rhythmicrhythmic movementmovement that carries that carries energyenergy through matter or space.through matter or space.

•In oceans, waves move In oceans, waves move through through seawaterseawater

•What causes waves?What causes waves?

WavesWaves

Caused byCaused by::

•WindWind

•EarthquakesEarthquakes

•Gravitational force of the Gravitational force of the Moon and Sun.Moon and Sun.

Parts of a WaveParts of a Wave

•CrestCrest – highest point of a wave – highest point of a wave

•Trough Trough – lowest point of a wave– lowest point of a wave

•Wave HeightWave Height – vertical distance – vertical distance between the crest and the troughbetween the crest and the trough

•WavelengthWavelength – horizontal distance – horizontal distance between two crests or two troughsbetween two crests or two troughs

Wavelength

Wave Height

Crest

Trough

Still Water

Wave Parts

Objectives

• IdentifyIdentify the parts of a wave. the parts of a wave.

• ExplainExplain how the parts of a wave relate how the parts of a wave relate to wave movement.to wave movement.

• DescribeDescribe how ocean waves form and how ocean waves form and move.move.

• ClassifyClassify types of waves. types of waves.

Wave Formation and Movement

• Most waves form as wind blows across Most waves form as wind blows across the water’s surface and transfers energy the water’s surface and transfers energy to the water.to the water.

• As the energy moves through the As the energy moves through the water, so do the waves. But the water water, so do the waves. But the water itself stays behind, rising and falling in itself stays behind, rising and falling in circular movements.circular movements.

Formation and Movement of Ocean Waves

Click below to watch the Visual Concept.

Visual Concept

Wave MovementWave Movement

•When a wave passes through When a wave passes through the ocean, the ocean, individual water individual water molecules move up and down molecules move up and down but they do not move forward but they do not move forward or backward with the wave.or backward with the wave.

Waves Caused by WindWaves Caused by Wind

•When wind blows across a body of When wind blows across a body of water, water, frictionfriction causes the water to causes the water to move along with the wind.move along with the wind.

•Wave Height depends on – Wave Height depends on – – Wind speedWind speed– Distance over which the wind blowsDistance over which the wind blows– Length of time the wind blowsLength of time the wind blows

Specifics of Wave Movement

• Waves not only come in different Waves not only come in different sizes but also travel at different sizes but also travel at different speeds. Wave speed is calculated speeds. Wave speed is calculated by using the following equation:by using the following equation:

wwaa vvee ppeerr iioo dd (s)(s)wwaa vveelleennggtthh (m)(m) == ww aavvee ssppeeeedd (m/s)(m/s)

• How does water move in the ocean?• Can you name types of waves or

other ocean wave parts?

Wave MovementWave Movement

•When a wave breaks against When a wave breaks against the shore, the shore, the crest outruns the the crest outruns the trough and the crest collapses.trough and the crest collapses.

•Called aCalled a breaker. breaker.

•In this case, water does move In this case, water does move forward and backward.forward and backward.

Objectives

• IdentifyIdentify the parts of a wave. the parts of a wave.

• ExplainExplain how the parts of a wave relate how the parts of a wave relate to wave movement.to wave movement.

• DescribeDescribe how ocean waves form and how ocean waves form and move.move.

• ClassifyClassify types of waves. types of waves.

Wave MovementWave Movement• When a wave crashes on the beach head on, When a wave crashes on the beach head on,

the water flows back to the ocean the water flows back to the ocean underneath the new incoming wave creating underneath the new incoming wave creating an an undertow.undertow.

• Undertow- a subsurface current that is near Undertow- a subsurface current that is near the shore and pulls objects out to sea.the shore and pulls objects out to sea.

Wave MovementWave Movement

• When a wave hits When a wave hits the shore at an angle the shore at an angle instead of head on it instead of head on it is called a is called a long shore long shore current.current.

• Long shore current- a Long shore current- a current that travels current that travels near and parallel to near and parallel to the shore line.the shore line.

Wave Movement-Open Ocean Wave Movement-Open Ocean waveswaves

• White caps- bubbles in the crest of a White caps- bubbles in the crest of a breaking wave.breaking wave.

• These are seen during stormy These are seen during stormy weather.weather.

Open Ocean WavesOpen Ocean Waves

• Swells- rolling Swells- rolling steady waves that steady waves that travel great travel great distances.distances.

• These are the These are the types of waves types of waves during sunny nice during sunny nice days/nights.days/nights.

TsunamisTsunamis• Giant ocean waves that form after Giant ocean waves that form after

volcanic eruption, submarine earth volcanic eruption, submarine earth quake, and land slidesquake, and land slides

• WWaves that form when a large aves that form when a large volume of ocean water is suddenly volume of ocean water is suddenly moved up or down.moved up or down.

Types of Waves, continued

• Storm Surges Storm Surges are local rises in sea are local rises in sea level near the shore that are caused by level near the shore that are caused by strong winds from a storm. strong winds from a storm.

• Winds form a storm surge by blowing Winds form a storm surge by blowing water into a big pile under the storm. As water into a big pile under the storm. As the storm moves onto shore, so does the storm moves onto shore, so does the giant mass of water beneath it.the giant mass of water beneath it.

Objectives

• IdentifyIdentify the parts of a wave. the parts of a wave.

• ExplainExplain how the parts of a wave relate how the parts of a wave relate to wave movement.to wave movement.

• DescribeDescribe how ocean waves form and how ocean waves form and move.move.

• ClassifyClassify types of waves. types of waves.