Exploring the OceanExploring the Ocean

Earth’s OceansEarth’s Oceans• Oceanographer – someone who studies Oceanographer – someone who studies

the oceanthe ocean

• Cover 71% of the planetCover 71% of the planet

• Contain 97% of Earth’s waterContain 97% of Earth’s water

• Source of fresh water for all living thingsSource of fresh water for all living things– Fresh water escapes as water vapor; salts left Fresh water escapes as water vapor; salts left

behindbehind– Water vapor in the atmosphere condenses to Water vapor in the atmosphere condenses to

form clouds and precipitationform clouds and precipitation– Part of the water cycle, some runs into rivers, Part of the water cycle, some runs into rivers,

streams and becomes ground water and some streams and becomes ground water and some back into the oceanback into the ocean

4 Major Oceans4 Major Oceans• Pacific OceanPacific Ocean

– Largest oceanLargest ocean; greater than Atlantic and Indian ; greater than Atlantic and Indian combinedcombined

– Deepest oceanDeepest ocean; avg. depth nearly 4,000 m; avg. depth nearly 4,000 m

• Atlantic OceanAtlantic Ocean– second largest ocean; second largest ocean; ½ size of the Pacific½ size of the Pacific– smaller Mediterranean Sea, Black Sea part of itsmaller Mediterranean Sea, Black Sea part of it

• Indian OceanIndian Ocean– Third largest oceanThird largest ocean

• Arctic OceanArctic Ocean– Smallest oceanSmallest ocean– Most of it is covered by iceMost of it is covered by ice

How did the Oceans form?How did the Oceans form?• As the Earth’s atmosphere developed, the As the Earth’s atmosphere developed, the

Earth was cooling. Earth was cooling.

• Sometime before 4 billion years ago, the Sometime before 4 billion years ago, the Earth cooled enough for water vapor to Earth cooled enough for water vapor to condense and fall as rain.condense and fall as rain.

• About 245 million years ago, one ocean About 245 million years ago, one ocean formed called Panthalassaformed called Panthalassa

• Atlantic and Indian formed first; about 180 Atlantic and Indian formed first; about 180 million years agomillion years ago

• Today, the plates move 1-10 cm per year…Today, the plates move 1-10 cm per year…Atlantic Ocean getting bigger and Pacific Atlantic Ocean getting bigger and Pacific Ocean getting smallerOcean getting smaller

Characteristics of Ocean Characteristics of Ocean WaterWater

• Mixture of gases and solids dissolved Mixture of gases and solids dissolved (pg 332)(pg 332)

• Gases are Hydrogen, Nitrogen, and carbon Gases are Hydrogen, Nitrogen, and carbon dioxidedioxide

• Sodium chloride most abundant salt (NaCl)Sodium chloride most abundant salt (NaCl)

• Salt acts like an antifreeze and keeps fresh Salt acts like an antifreeze and keeps fresh water from freezing.water from freezing.

• Salinity = amount of dissolved salt in the waterSalinity = amount of dissolved salt in the water– Measured in parts per thousandMeasured in parts per thousand– 1 kg (1,000 g) of ocean water contains about 35 g of 1 kg (1,000 g) of ocean water contains about 35 g of

dissolved solids on averagedissolved solids on average– so we say 35 parts per thousand avg. salinityso we say 35 parts per thousand avg. salinity

Factors that Affect SalinityFactors that Affect Salinity• Some areas of the ocean are saltier Some areas of the ocean are saltier

than othersthan others

• Water movementWater movement– Slow moving water has higher salinity pg. Slow moving water has higher salinity pg.

333333

• Coastal areas where major rivers flow Coastal areas where major rivers flow into the ocean have lower salinityinto the ocean have lower salinity

• Climate: Hotter areas are higher salinityClimate: Hotter areas are higher salinity– Less fresh water runs into the ocean in Less fresh water runs into the ocean in

drier areas; heat increases evaporation drier areas; heat increases evaporation rates.rates.

OceanOceanTemperatureTemperature

• Decreases the Decreases the deeper you go deeper you go (gets colder)(gets colder)

• 3 temperature 3 temperature zoneszones– Surface ZoneSurface Zone– ThermoclineThermocline– Deep ZoneDeep Zone

Temperature ZonesTemperature Zones• Surface ZoneSurface Zone

– Goes down 300 mGoes down 300 m– Sun heats up to 100 mSun heats up to 100 m

• ThermoclineThermocline– Starts at 300 m to 700 mStarts at 300 m to 700 m– Temperature drops faster with depth Temperature drops faster with depth

than any other zonethan any other zone

• Deep ZoneDeep Zone– Starts at 700 m to bottomStarts at 700 m to bottom– Temperature averages 2 degrees celsiusTemperature averages 2 degrees celsius

Surface TemperaturesSurface Temperatures

• Vary with latitude and time of yearVary with latitude and time of year• Ranges from 1 degree C near the Ranges from 1 degree C near the

poles to about 24 degrees C at the poles to about 24 degrees C at the equatorequator

• Sun hits more directly at equator so it Sun hits more directly at equator so it is always warmeris always warmer

• In the summer, it hits more directly in In the summer, it hits more directly in Northern Hemisphere so oceans get Northern Hemisphere so oceans get warmer (colder in winter)warmer (colder in winter)

Density of Density of Ocean Ocean WaterWater• Cold water is Cold water is

denser than denser than warm waterwarm water

• Salt water is Salt water is denser than denser than fresh waterfresh water

• What happens What happens when cold when cold currents meet currents meet warm warm currents?currents?

Three Main Groups of Marine Three Main Groups of Marine LifeLife• Plankton Plankton

– Organisms that float at or near the surfaceOrganisms that float at or near the surface– Zooplankton, phytoplanktonZooplankton, phytoplankton

• Nekton Nekton – Free-swimming organismsFree-swimming organisms– Dolphins, whales, sea lionsDolphins, whales, sea lions

• BenthosBenthos– Organisms that live on the ocean floorOrganisms that live on the ocean floor– Crabs, sea stars, worms, coral, sponges, Crabs, sea stars, worms, coral, sponges,

seaweedseaweed

Benthic EnvironmentBenthic Environment• Intertidal Zone Intertidal Zone

– area located between low-tide and high-tide area located between low-tide and high-tide lines.lines.

– Organisms need to be able to survive in and Organisms need to be able to survive in and out of the waterout of the water

– Sea anemones and starfishSea anemones and starfish

• Sublittoral Zone Sublittoral Zone – Extends from low-tide line to the end of Extends from low-tide line to the end of

continental shelfcontinental shelf– more stable than the intertidal zonemore stable than the intertidal zone– temperature, pressure and sunlight remain temperature, pressure and sunlight remain

fairly constantfairly constant– coralscorals

Benthic Environment Benthic Environment (continued)(continued)• Bathyal Zone – continental shelf to the Bathyal Zone – continental shelf to the

abyssal plainabyssal plain– lacks sunlight, plant life is scarcelacks sunlight, plant life is scarce– Sponges, sea stars, octopusesSponges, sea stars, octopuses

• Abyssal Zone Abyssal Zone – No plants and few animalsNo plants and few animals– Crabs, sponges, worms, sea cucumbers Crabs, sponges, worms, sea cucumbers

• Hadal Zone Hadal Zone – DeepestDeepest– TrenchesTrenches– Little known; found few species of clams and Little known; found few species of clams and

wormsworms

Ocean Resources - LivingOcean Resources - Living

• FishingFishing– Sonar, drift nets help fishing industriesSonar, drift nets help fishing industries– Overfishing concernsOverfishing concerns– Fishing laws prompted fishing hatcheriesFishing laws prompted fishing hatcheries

• Seaweed HarvestingSeaweed Harvesting– Shrimp, oysters, crabs, mussels raised in Shrimp, oysters, crabs, mussels raised in

enclosed areas along the shore.enclosed areas along the shore.– Thickens creams, jellies, and yes! Ice Thickens creams, jellies, and yes! Ice

CreamCream

Ocean Resources – Non Ocean Resources – Non LivingLiving

• Oil and GasOil and Gas– Found in layers of impermeable rockFound in layers of impermeable rock– Seismic equipment sends pulses through the Seismic equipment sends pulses through the

earth to find areasearth to find areas

• Fresh WaterFresh Water– Desalination – process of evaporating sea water Desalination – process of evaporating sea water

to separate the saltto separate the salt– Very costly – countries rely on rainfallVery costly – countries rely on rainfall– Saudi Arabia - Middle East desert region – has Saudi Arabia - Middle East desert region – has

one of the largest desalination plants in the one of the largest desalination plants in the worldworld

• MineralsMinerals– Manganese, iron, copper, nickel, cobalt, Manganese, iron, copper, nickel, cobalt,

phosphatesphosphates

Ocean ResourcesOcean Resources

• Tidal Energy and Wave EnergyTidal Energy and Wave Energy– As tides rise and fall, and as waves As tides rise and fall, and as waves

crash on the shore, we can use the crash on the shore, we can use the gravitational pull and force to create gravitational pull and force to create electricityelectricity

– Both are renewable resources of energyBoth are renewable resources of energy

Ocean PollutionOcean Pollution• Trash DumpingTrash Dumping

– Millions of trash is dumped in the deep ocean Millions of trash is dumped in the deep ocean – U.S. started requiring hospitals to bury medical U.S. started requiring hospitals to bury medical

waste in sanitary landfillswaste in sanitary landfills

• Sludge DumpingSludge Dumping– Raw sewageRaw sewage

• Non-Point sourceNon-Point source– Everyday pollution from peopleEveryday pollution from people

• Point sourcePoint source– Oil spillsOil spills– Today, tankers are required to have double Today, tankers are required to have double

hullshulls

Take Action – Save our Take Action – Save our OceansOceans• In 1989, 64 countries ratified a treaty that In 1989, 64 countries ratified a treaty that

prohibited the dumping of mercury, cadmium prohibited the dumping of mercury, cadmium compounds, certain plastics, oil, and radioactive compounds, certain plastics, oil, and radioactive wastes.wastes.

• Tough to enforce due to angencies lacking human Tough to enforce due to angencies lacking human resources and money.resources and money.

• Citizens of many countries have demanded that Citizens of many countries have demanded that their governments do more to solve the ocean their governments do more to solve the ocean pollution problem.pollution problem.– Because of Public outcry in the U.S., more than $130 Because of Public outcry in the U.S., more than $130

million each years goes to monitoring the ocean.million each years goes to monitoring the ocean.– People also volunteer to Adopt-a Beach and show up People also volunteer to Adopt-a Beach and show up

anually to clean up beaches in organized groups.anually to clean up beaches in organized groups.

• Why does the Ocean have waves?Why does the Ocean have waves?

• What are the parts of a wave?What are the parts of a wave?

• How does water move in a wave?How does water move in a wave?

• What happens when a wave hits a What happens when a wave hits a beach?beach?

Define wave:Define wave:

• Wave – a rhythmic movement that Wave – a rhythmic movement that carries energy through matter or carries energy through matter or space.space.– in the ocean, waves move through in the ocean, waves move through

seawater.seawater.

Parts of a waveParts of a wave

Crest Crest

Trough

Wavelength

Wave height

Parts of a wave:Parts of a wave:

• CrestCrest – the highest part of a wave. – the highest part of a wave.

• TroughTrough – the lowest part of a wave. – the lowest part of a wave.

• WavelengthWavelength – the distance between – the distance between two adjacent crests.two adjacent crests.

• Wave heightWave height – the vertical distance – the vertical distance between the lowest part and the between the lowest part and the highest part.highest part.

More wave More wave wordswords

• But Mr. Coleman, why do we But Mr. Coleman, why do we have to learn vocabulary words have to learn vocabulary words that aren’t in the book?that aren’t in the book?

For the FCAT!

Frequency – the number of complete waves (or oscillations) that occur over a given period of time. Usually measured in cycles per second.

Amplitude – half the wave height

Most waves caused by windMost waves caused by wind

• Friction from the wind moving over Friction from the wind moving over the water causes the water to move the water causes the water to move along with the wind.along with the wind.

• If the wind speed is high enough, the If the wind speed is high enough, the water begins to pile up and a wave is water begins to pile up and a wave is formed.formed.

How does water move in a How does water move in a wave?wave?

Some clues:Some clues:

• When you were at the beach, you When you were at the beach, you probably noticed that the edge of probably noticed that the edge of the water goes back and forth with the water goes back and forth with the waves.the waves.

• If you float an object on the ocean, If you float an object on the ocean, it stays roughly in one place. It is it stays roughly in one place. It is not pushed forward by the waves.not pushed forward by the waves.

How water moves in a How water moves in a wave:wave:

Particles of water move around in circles. The farther below the surface, the smaller the circle.

At a depth about equal to half the wavelength, the motion stops.

At the beach:At the beach:• Wavelength decrease and wave height Wavelength decrease and wave height

increases as waves approach the shore.increases as waves approach the shore.

Constant

Wavelength

Waves drag against the bottom

and wave length decreases

At the beach, part 2At the beach, part 2• As the wave slows, its crest and trough come As the wave slows, its crest and trough come

closer together. The top of the wave is not closer together. The top of the wave is not slowed by friction and moves faster than the slowed by friction and moves faster than the bottom.bottom.

Now we wave goodbye to this part Now we wave goodbye to this part of the lesson,of the lesson,

for for now.now.