OceanographyOceanography

Earth’s OceansEarth’s Oceans

Earth is a special planet because of Earth is a special planet because of liquid waterliquid water

71% of earth’s surface is water71% of earth’s surface is water Ocean divided by continentsOcean divided by continents

4 Major Ocean Divisions 4 Major Ocean Divisions

Pacific OceanPacific Ocean Volume 724 million cubic kilometersVolume 724 million cubic kilometers

Atlantic OceanAtlantic Ocean 322 million cubic kilometers322 million cubic kilometers

IndianIndian 292 million cubic kilometers292 million cubic kilometers

ArcticArctic 12 million cubic kilometers12 million cubic kilometers

Ocean FormationOcean Formation

Two theoriesTwo theories Out-gassingOut-gassing Big SplatBig Splat

Out-gassingOut-gassing Volcanic vents released gases that Volcanic vents released gases that

cooled to form our oceanscooled to form our oceans Big SplatBig Splat

Extraterrestrial comets delivered our Extraterrestrial comets delivered our waterwater

Plate Tectonics Effect on Plate Tectonics Effect on OceansOceans

Plate tectonics causes lithosphere Plate tectonics causes lithosphere to moveto move

As crust changes, oceans change As crust changes, oceans change shapeshape

245 mya continents formed 245 mya continents formed PangaeaPangaea Oceans formed PanthalassaOceans formed Panthalassa

Characteristics of Ocean Characteristics of Ocean WaterWater

Chemical composition is similar toChemical composition is similar to NaCl, Sodium Chloride, table saltNaCl, Sodium Chloride, table salt Chlorine is the most abundant Chlorine is the most abundant

elementelement SalinitySalinity

Measured amount of salt and solids in Measured amount of salt and solids in a given amount of liquida given amount of liquid

Factors affecting SalinityFactors affecting Salinity EvaporationEvaporation

Hot dry climate increases evaporationHot dry climate increases evaporation Less water more salt = high salinityLess water more salt = high salinity

River outlets/precipitationRiver outlets/precipitation Increase of fresh water dilutes ocean Increase of fresh water dilutes ocean

water = lower salinitywater = lower salinity CurrentsCurrents

Currents mix water causing water to Currents mix water causing water to become diluted = lower salinitybecome diluted = lower salinity

Temperature ZonesTemperature Zones

Water Column: vertical aspect of oceanWater Column: vertical aspect of ocean As depth IncreasesAs depth Increases

Pressure increases, Temperature Pressure increases, Temperature decreasesdecreases

3 Zones3 Zones SurfaceSurface Transition/ThermoclineTransition/Thermocline Deep zoneDeep zone

Surface ZoneSurface Zone

Warm top layerWarm top layer Extends down 300 metersExtends down 300 meters Sunlight warms only top 100 metersSunlight warms only top 100 meters

How does zone maintain temperature?How does zone maintain temperature? Average temp is 24Average temp is 24°C°C Varies with latitude and time of yearVaries with latitude and time of year

Rather swim near Alaska or Florida?Rather swim near Alaska or Florida? Swim during summer or winter?Swim during summer or winter?

Transition/ThermoclineTransition/Thermocline

Range is 300 to 700 metersRange is 300 to 700 meters Water temp decreases the Water temp decreases the

greatest in this zonegreatest in this zone Begins at 24Begins at 24°C°C Ends at 5°CEnds at 5°C

Deep ZoneDeep Zone

Range 700 to ocean floor 1,200 Range 700 to ocean floor 1,200 MetersMeters

Average temp is 2Average temp is 2°C°C Deepest part of the ocean is below Deepest part of the ocean is below

zero, yet water doesn’t freeze, zero, yet water doesn’t freeze, why?why?

Water CycleWater Cycle Cycle that links all Earth’s solid, Cycle that links all Earth’s solid,

liquid and gaseous water. 3 parts liquid and gaseous water. 3 parts are:are:

CondensationCondensation Gas to a liquidGas to a liquid

PrecipitationPrecipitation Solid or liquid water falls to earthSolid or liquid water falls to earth

EvaporationEvaporation Liquid to a gasLiquid to a gas