earth’s oceans. the oceans the water on earth is divided into oceans the water on earth is divided...

Earth’s OceansEarth’s Oceans

The OceansThe Oceans

The water on Earth is The water on Earth is divided into oceansdivided into oceans

1. 1. Pacific Ocean – biggestPacific Ocean – biggest 2. 2. Atlantic OceanAtlantic Ocean3. 3. Indian OceanIndian Ocean4. 4. Arctic Ocean – smallestArctic Ocean – smallest

Origin of the OceansOrigin of the Oceans

4.5 billion years ago 4.5 billion years ago there were there were no oceansno oceans on earth. on earth.

VolcanoesVolcanoes spewed spewed gases into the air to gases into the air to form the atmosphereform the atmosphere

Origin of the OceansOrigin of the Oceans

As the Earth began to cool, As the Earth began to cool, water vaporwater vapor began to began to condense and form raincondense and form rain

This rain filled the deeper This rain filled the deeper levels of the Earth’s surface levels of the Earth’s surface which created which created our oceansour oceans

Composition of the Composition of the OceanOcean

Ocean water contains Ocean water contains many many dissolved salts.dissolved salts.

Running waterRunning water from from rivers carries these salts rivers carries these salts from land to the oceanfrom land to the ocean

Composition of the Composition of the OceanOcean

When seawater is When seawater is evaporated, ions combine to evaporated, ions combine to from materials called from materials called salts.salts.

Sodium and chlorideSodium and chloride make make up most of the ions in up most of the ions in seawater.seawater.

SaltsSalts

SalinitySalinity is a measure of is a measure of the amount of salts the amount of salts dissolved in seawater.dissolved in seawater.

One kilogram of ocean One kilogram of ocean water contains about water contains about 35 g35 g of dissolved salts, or 3.5%of dissolved salts, or 3.5%

Climate and SalinityClimate and Salinity

Hotter, drier climates Hotter, drier climates typically have a typically have a higher higher salinitysalinity

Cooler, humid climates Cooler, humid climates have a have a lower salinitylower salinity

Temperature ZonesTemperature Zones

The temperature of the ocean The temperature of the ocean decreasesdecreases as the depth as the depth increases, increases, the colder the water the more the colder the water the more oxygen it can hold.oxygen it can hold.

The The three zonesthree zones are are surface zones, thermocline, surface zones, thermocline, and deep zoneand deep zone

Temperature ZonesTemperature Zones

The The surface zonesurface zone is the is the warm, top layer of the ocean warm, top layer of the ocean waterwater

The The thermocline thermocline is the is the second layer of the ocean second layer of the ocean where the temperature where the temperature drops significantlydrops significantly

Temperature ZonesTemperature Zones

The The deep zonedeep zone is the is the bottom layer of the bottom layer of the ocean where ocean where temperature ranges temperature ranges from 1from 1°C to 3°C°C to 3°C

Ocean’s Water CycleOcean’s Water Cycle

The The water cycle water cycle also also takes place in the oceantakes place in the ocean

The three parts are The three parts are EvaporationEvaporationCondensationCondensationPrecipitationPrecipitation

Holding HeatHolding Heat

The oceans ability to The oceans ability to absorb and holdabsorb and hold heat heat makes Earth suitable for lifemakes Earth suitable for life

The oceans absorb and The oceans absorb and release heat release heat more slowlymore slowly than land doesthan land does

Warm water CirculationWarm water Circulation

Water at the equator is Water at the equator is warmer warmer than other regions than other regions

CurrentsCurrents in the ocean move in the ocean move this warm water around the this warm water around the worldworld

This allows This allows coastal landscoastal lands to to have warmer than normal have warmer than normal climatesclimates

Ocean CurrentsOcean Currents

Ocean currents are a Ocean currents are a mass movement, or mass movement, or flow,flow, of ocean water. of ocean water.

An An ocean currentocean current is like is like a river within the oceana river within the ocean

Ocean CurrentsOcean Currents

Ocean currents are a Ocean currents are a mass movement, or mass movement, or flow,flow, of ocean water. of ocean water.

An An ocean currentocean current is like is like a river within the oceana river within the ocean

CurrentsCurrents

Ocean CurrentsOcean Currents

Ocean currents are a Ocean currents are a mass movement, or mass movement, or flow,flow, of ocean water. of ocean water.

An An ocean currentocean current is like is like a river within the oceana river within the ocean

Surface CurrentsSurface Currents

Surface currentsSurface currents move move water horizontally— water horizontally— parallel to Earth’s parallel to Earth’s surface.surface.

These currents are These currents are powered by powered by wind.wind.

Surface CurrentsSurface Currents

Surface currents Surface currents move only the move only the upper upper few hundredfew hundred meters meters of seawater.of seawater.

Origin of Surface Origin of Surface CurrentsCurrents

The The Coriolis effectCoriolis effect is the shifting of is the shifting of winds and surface winds and surface currents caused by currents caused by Earth’s rotation.Earth’s rotation.

Origin of Surface Origin of Surface CurrentsCurrents

Because Earth rotates Because Earth rotates toward the east, winds toward the east, winds curve to the curve to the rightright in the in the northern hemisphere northern hemisphere and to the and to the left left in the in the southern hemisphere.southern hemisphere.

Origin of Surface Origin of Surface CurrentsCurrents

The Coriolis effect The Coriolis effect causes currents north of causes currents north of the equator to turn to the equator to turn to the the right.right. Currents Currents south of the equator are south of the equator are turned turned left.left.

Warm vs. Cold CurrentsWarm vs. Cold Currents

Currents on the Currents on the west west coastscoasts of continents of continents begin near the poles begin near the poles where the water is where the water is colder.colder.

Warm vs. Cold CurrentsWarm vs. Cold Currents

East-coastEast-coast currents currents originate near the originate near the equator where the equator where the water is warmer (Gulf water is warmer (Gulf Stream Current)Stream Current)

UpwellingUpwelling

Upwelling Upwelling is a is a vertical circulation in vertical circulation in the ocean that brings the ocean that brings deep, cold water to deep, cold water to the ocean surface.the ocean surface.

UpwellingUpwelling

This water contains This water contains high concentrations high concentrations of of nutrientsnutrients from from organisms that died.organisms that died.

UpwellingUpwelling

Nutrients promote Nutrients promote primary productionprimary production and and plankton growth, which plankton growth, which attracts fish.attracts fish.

Areas of upwelling create Areas of upwelling create important important fishing groundsfishing grounds

Deep CurrentDeep Current

A A deep currentdeep current is a is a streamlike movement streamlike movement of ocean water far of ocean water far below the surface below the surface caused by differences caused by differences in densityin density

Density CurrentsDensity Currents

The The density density of seawater of seawater increases if increases if salinity salinity increases.increases.

It also increases whenIt also increases when temperaturetemperature decreases. decreases.

Deep CurrentDeep Current

An important density current An important density current begins in begins in Antarctica.Antarctica.

As ice forms, seawater As ice forms, seawater freezes, but the salt is freezes, but the salt is left left behindbehind in the unfrozen in the unfrozen water.water.

Deep CurrentsDeep Currents

This salt increases the This salt increases the density of the water until it density of the water until it sinks and forms a sinks and forms a deep deep currentcurrent

This current then slowly This current then slowly makes its way makes its way towards the towards the equatorequator

Deep CurrentsDeep Currents

In the In the North Atlantic North Atlantic OceanOcean, cold, dense water , cold, dense water forms.forms.

These waters sink, These waters sink, forming forming North Atlantic North Atlantic Deep Water.Deep Water.

Intermediate WatersIntermediate Waters

In the Mediterranean, In the Mediterranean, hot temperatures cause hot temperatures cause water vapor in the water vapor in the ocean to evaporate ocean to evaporate which which increases the increases the salinitysalinity of the water of the water

Intermediate WatersIntermediate Waters

This water is This water is not as densenot as dense as the North Atlantic Deep as the North Atlantic Deep CurrentCurrent

It then forms a middle layer It then forms a middle layer of water called the of water called the Mediterranean Mediterranean Intermediate WatersIntermediate Waters

The Ocean FloorThe Ocean Floor

Studying the Ocean FloorStudying the Ocean Floor

Scientists use Scientists use sonarsonar to to determine the oceans depthdetermine the oceans depth

The The sound movessound moves through through the water, bounces off the the water, bounces off the ocean floor, and returns to ocean floor, and returns to the shipthe ship

Ocean BasinsOcean Basins

Ocean basinsOcean basins are low areas are low areas of Earth that are filled with of Earth that are filled with waterwater

The The continental shelfcontinental shelf is the is the gradually sloping end of a gradually sloping end of a continent that extends under continent that extends under the ocean to 350 m deepthe ocean to 350 m deep

The Ocean FloorThe Ocean Floor

Beyond the shelf, the ocean Beyond the shelf, the ocean floor floor drops more steeplydrops more steeply, , forming the continental slope.forming the continental slope.

The The continental slopecontinental slope extends from the outer edge extends from the outer edge of the continental shelf down of the continental shelf down to the ocean floor.to the ocean floor.

Ocean BasinsOcean Basins

Beyond the continental Beyond the continental slope lie the slope lie the trenches, trenches, valleys, plains, valleys, plains, mountains,mountains, and ridges and ridges of the ocean basinof the ocean basin

Ocean BasinsOcean Basins

In the deep ocean, In the deep ocean, sedimentsediment, , derived mostly from land, derived mostly from land, settles constantly on the settles constantly on the ocean floor.ocean floor.

These deposits fill in valleys These deposits fill in valleys and create flat seafloor areas and create flat seafloor areas called called abyssal plainsabyssal plains..

The Ocean BasinsThe Ocean Basins

Some areas of Some areas of abyssal abyssal plainsplains have small hills have small hills and seamounts.and seamounts.

SeamountsSeamounts are are underwater, inactive underwater, inactive volcanic peaksvolcanic peaks

Ridges and TrenchesRidges and Trenches

Mid-ocean ridges can be Mid-ocean ridges can be found at the bottom of all found at the bottom of all ocean basins. ocean basins.

A A mid-ocean ridgemid-ocean ridge is the is the area in an ocean basin where area in an ocean basin where new ocean floor is formed.new ocean floor is formed.

Ridges and TrenchesRidges and Trenches

On the ocean floor, On the ocean floor, subduction zonessubduction zones are marked by deep are marked by deep ocean trenches.ocean trenches.

Trenches and RidgesTrenches and Ridges

A A trenchtrench is a long, narrow, is a long, narrow, steep-sided depression steep-sided depression where one plate sinks where one plate sinks beneath another.beneath another.

Marianna Trench in Pacific Marianna Trench in Pacific ocean deepest that we have ocean deepest that we have found “Challenger Deep” found “Challenger Deep” 11,000 meters.11,000 meters.

Pacific Ocean vs. Atlantic Pacific Ocean vs. Atlantic OceanOcean

The Pacific Ocean has a much steeper The Pacific Ocean has a much steeper continental slope.continental slope.

It hasIt has Submarine Canyons Submarine Canyons caused by caused by Turbidity CurrentsTurbidity Currents. These are fast . These are fast moving currents that move perpendicular moving currents that move perpendicular to the shoreline that cut into the to the shoreline that cut into the continental slope to form a canyon. continental slope to form a canyon.

The Atlantic ocean has more abyssal The Atlantic ocean has more abyssal plains because more rivers empty into plains because more rivers empty into into it bringing more sediment into it bringing more sediment

Life Zones Life Zones Intertidal Zone- found between high and low tide, Intertidal Zone- found between high and low tide,

contains benthos, nekton and plankton.contains benthos, nekton and plankton. Neritic Zone- low tide to continental shelf , Neritic Zone- low tide to continental shelf ,

contains, benthos, nekton and plankton.contains, benthos, nekton and plankton. Open sea Zone- largest of the zones, over the Open sea Zone- largest of the zones, over the

ocean floor. ocean floor. a. photosynthetic- surface, contains phytoplankton a. photosynthetic- surface, contains phytoplankton

and zooplanktonand zooplanktonb. Bathyal zone- small amount of light reaches here, b. Bathyal zone- small amount of light reaches here,

large nekton swim here, most fishing takes place large nekton swim here, most fishing takes place here, also plankton.here, also plankton.

c. Abyssal zone- to see floor, no light, strange c. Abyssal zone- to see floor, no light, strange creatures make own light.creatures make own light.

Life in the OceanLife in the Ocean

There are three groups of There are three groups of organisms that live in the organisms that live in the oceanoceanPlanktonPlanktonNektonNektonBenthosBenthos

PlanktonPlankton

PlanktonPlankton are organisms are organisms that float or drift freely near that float or drift freely near the ocean’s surfacethe ocean’s surface

Plankton are divided into Plankton are divided into phytoplanktonphytoplankton (plant-like) (plant-like) and and zooplanktonzooplankton (animal- (animal-like)like)

NektonNekton

Organisms that swim Organisms that swim openly in the ocean are openly in the ocean are called called nektonnekton

Nekton include Nekton include mammals mammals (whales, dolphins) and (whales, dolphins) and many types of many types of fishfish

BenthosBenthos

Benthos Benthos are are organisms that live on organisms that live on or in the ocean flooror in the ocean floor

These include These include crabscrabs, , starfish and coralstarfish and coral

Oceanic ZonesOceanic Zones

The ocean floor is divided The ocean floor is divided into zones based on into zones based on ecologyecology

The The benthic environmentbenthic environment is the region near the is the region near the ocean floorocean floor

Benthic EnvironmentBenthic Environment

Intertidal zoneIntertidal zone is is located between high located between high and low tidesand low tides

Sublittoral zoneSublittoral zone extends to the edge of extends to the edge of the continental shelfthe continental shelf

Benthic EnvironmentBenthic Environment

Bathyal zoneBathyal zone is located is located from the continental from the continental shelf to the abyssal planeshelf to the abyssal plane

The The abyssal zoneabyssal zone is is found on the abyssal found on the abyssal plainplain

Benthic EnvironmentBenthic Environment

The deepest zone is The deepest zone is the the hadal zonehadal zone , , found in trenches found in trenches (abyssal zone)(abyssal zone)

Oceanic ZonesOceanic Zones

The The pelagic pelagic environmentenvironment is the is the zone near the ocean’s zone near the ocean’s surface and the middle surface and the middle depths (photosynthetic depths (photosynthetic zone)zone)

Pelagic EnvironmentPelagic Environment

The The neritic zoneneritic zone covers covers the continental shelf the continental shelf

Contains the largest Contains the largest concentration of concentration of marine marine lifelife

Oceanic zoneOceanic zone covers the covers the rest of the ocean floorrest of the ocean floor

Resources from the Resources from the OceanOcean

The ocean offers a vast The ocean offers a vast supply of supply of resourcesresources

Food, raw materials, Food, raw materials, energy and drinkable energy and drinkable water are all water are all from the from the oceanocean

Living ResourcesLiving Resources

Fishing Fishing has become a has become a multi-billion dollar business multi-billion dollar business over the yearsover the years

Because over fishing has Because over fishing has become a problem, become a problem, fish fish farmsfarms have started to have started to flourishflourish

Living ResourcesLiving Resources

SeaweedSeaweed (kelp) is also (kelp) is also harvested from the harvested from the ocean ocean

Seaweed can be used to Seaweed can be used to thicken foodsthicken foods such as such as jellies and ice creamjellies and ice cream

DesalinationDesalination

Salt can be removed from Salt can be removed from ocean water by a process ocean water by a process called called desalination.desalination.

As seawater As seawater evaporatesevaporates, , salt is left behind.salt is left behind.

Sea-Floor MineralsSea-Floor Minerals

Elements such as sulfur Elements such as sulfur and metals like iron, and metals like iron, copper, zinc, and silver copper, zinc, and silver can be concentrated in can be concentrated in holes and cracksholes and cracks along along mid-ocean ridges.mid-ocean ridges.