The Hydrosphere

EarthandSpaceContinued

The Earth Consists of Overlapping Layers:1. Hydrosphere+Cryosphere

2. Atmosphere

3. Biosphere

4. Lithosphere

Hydrosphere

– Thehydrosphereisearth’souterlayerofwater.

– Watercanbefoundinmanyformsonearth:

– Saltwaterinoceans

– Freshwateronland

– Brackishwaterinoceansà brackishwaterisamixoffreshandsaltwater

– Frozenasice in: 1)IceFloes/SeaIce(iceinwater)2)Glaciers/IceCaps (Iceonland)

Water on Land

Catchment Areas AKA Watersheds

– ACatchmentAreaorWatershedisanareaonlandwhereallinlandwater(suchasriversandstreams)meettodrainintothesamelargerbodyofwater(suchasanocean)

– SimpleDefinition:Acatchmentareaisaterritoryoflandsurroundingawaterway

– 5Factorsaffectingtheflowofwaterinthewatershed:

1) Topography:theshape,slopeandterrainofthearea

2) Geology:thetype,depthandstructureofrock,abilityofthesoiltoabsorbthemoisture

3) Climate: precipitation,temperatureandwinds

4) Vegetation:densityanddiversityofplantlife.

5) HumanActivity: Agricultural,industrialandurbandevelopments

Catchment Areas AKA Watersheds

Factors affecting the flow of water in the watershed

1) Topography:theshape,slopeandterrainofthearea

ForExample:Ifthereisamountain,thenthewaterwillflowdownonesideortheother

Shape

SlopeTerrain

Water has been added to both Sand and Rocks. What do you observe?

Sand Gravel

2)Geology:thetype,depthandstructureofrock,abilityofthesoiltoabsorbthemoisture

ForExample:Sandcanabsorbmoisturebutgravelrockcannot,thismeansthatwaterwilldrainrightthroughlargerocksbutwillgetpartlyabsorbedintosandandfineparticlesifflowingslowly.

Factors affecting the flow of water in the watershed

3)Climate:precipitation(rain/snow),temperatureandwinds

Factors affecting the flow of water in the watershed

Amountofsunandwindcanaffecttheamountofevaporationofwateroccurring.

Excessiveamountofprecipitationcanincreasetheamountofwater/causefloodingofareas

Given the image below, what impact do you think trees have on the ability of water to flow over an area?

4)Vegetation:densityanddiversityofplantlife.

à Plantsabsorbwaterandkeepwaterinthesoilaroundthem.Thismeansthatmorewaterwillstayinthearethanifthereweretoplants.

Example:Ifanareahaslotsoftrees,thentheirrootswillkeepsoilandrocksinplace.Thisallowsforresistancetoerosion(leavingofsoil)whenwaterflowsovertheland.

Factors affecting the flow of water in the watershed

With the person next to you, discuss how the flow of water could be affected by the following Human Activities:

A) AgriculturalFields

AND

B)Industrial(suchasmining)andUrbanDevelopments

5)HumanActivity: Agricultural,industrialandurbandevelopments

Agricultural:____________________________________________

__________________________________________

IndustrialandUrbanDevelopments:_________________________

_______________________________________________________

Factors affecting the flow of water in the watershed

https://www.youtube.com/watch?v=iyTWj2LZfOM

– Pollutingupriver,canhavedevastatingeffectsdownstreaminthewatershed.

– VideoForReference:https://www.youtube.com/watch?v=iyTWj2LZfOM

The Oceans

– Oceansaredividedbythecontinents:

PacificOcean,AtlanticOcean,IndianOcean,ArcticOceanandtheAntarctic(Southern)Ocean

– Oceanscontain97%oftheEarth’swater

The Oceans

The Oceans

The Oceans

– Oceanwatersaremovedbycurrentsthatcarrythemallaroundtheworld

à thewaterinoceansisconstantlycirculating.

– WaterTemperatureandSalinity(theamountofsaltintheocean)areimportantcharacteristicsoftheoceananddeterminecurrentmovement

The Thermohaline CirculationAKA Oceanic Circulation

– ThermomeansTemperature

– HalinemeansSalt

– Oceancirculationsaredeterminedbythetemperature(thermo)andamountofsalt(haline)inthewaterindifferentareas!

Factors that affect the Thermohaline Circulation1) Temperature

2) Salinityßà Densityofoceanwater

3) Winds

4) Earth’sRotation

Factors that affect the Thermohaline Circulation1)Watertemperatureisaffectedbythefollowing:

a.Depthà thedeeperthewateris,thelesssunlightthereistowarmthewater,thereforethewateriscolder

b.Seasonsà lessdirectsunlightinwinter

c.Latitudeà waterneartheequatoriswarmerthanwaternearthepoles

Temperature of the Oceans

InWords…

• Asyoudecreaseindepth(asyougodeeperintheocean)thetemperatureofthewatergetscolder.

• Thismakesensebecausethesunwarmsupthewater,sotheclosertothesurfacethewateris,thewarmerthewateris.

2)Salinity(amountofsaltdissolvedinaliquid)isaffectedby:a.Heatanddroughtà whenthereisalotofheat,thewaterwillevaporate,leavingmoresaltsinthewater(raisingtheconcentrationofsalts)

b.FreezingSeawaterà saltisforcedoutoftheicecrystalswhenseaiceforms,causingthesurroundingwatertobecomesaltier

b.Meltingpackiceandglaciersà dilutetheseawaterandreducethesaltcontent

Factors that affect the Thermohaline Circulation

3)Winds:Surfaceoceancurrentsareprimarilyaffectedbywindpatterns. Tradewinds(strongseasonalwinds)canpushwateralongthetopoftheoceanandaidintheformationofsurfacecurrents.

Factors that affect the Thermohaline Circulation

4)Earth’sRotation:

Factors that affect the Thermohaline Circulation

You can see the ocean currents deflecting due to Earth’s rotation in the Northern and Southern Hemispheres.

Oceanic Circulation

– Anoceancurrentisthemovementofseawaterinacertaindirection

– 2maintypesofoceancurrents:

– surfacecurrents:mostlywinddriven,theymovehorizontally

– subsurfacecurrents:mostlyduetovariationsindensity

– Oceancirculationisthecombinedeffectofallthecurrentsthatmoveacrosstheocean

Density and Subsurface Currents

– Subsurfacecurrents:mostlyduetovariationsindensity.

– Thecolder thewater,themoredense itis,soitsinksbelowthelessdensewaterandmovesalongtheoceanfloor.

– Densitydifferencesarealsocausedbydifferencesinsalinity.

à themoresaltthereisinthewaterthemoredenseitis.

Density of Ocean Water

Less Dense MoreDense

Salinity(AmountofSalt)

LESSSALT MORESALT

Temperature WARMER COLDER

Thermohaline Circulation

– Thermohalinecirculationisahuge“conveyorbelt”formedbysurfaceandsubsurfacecurrentsthatmoveswaterallaroundtheworld.

– IthelpstoregulatetheEarth’sclimatebymovingheataroundtheworld

Ocean Conveyor Belt

The Cryosphere

AllofthefrozenIceonEarth

2 Types of Frozen Water:

1)PackIce(IceFloes):

– Composedofseawaterthathasfrozeninthewinter

– Expandsduringwintertocoverabout5%ofthenorthernoceansand8%ofthesouthernoceans

– Isimportanttoglobaloceancirculationandclimatepatterns

– Packiceitselfisnowendangeredbecauseofglobalwarming

The Global Effects of Melting Pack Ice

1) MeltingPackIceIncreasestheAmountofFreshWaterinthesurroundingarea:

ChangesinfreshwaterinputstotheNorthAtlanticmayaltertheglobaloceancurrentswithfar-reachingeffectsontheglobalclimate.

2) TheamountofsolarenergyabsorbedbyArcticseasincreaseswithlargeareasofopenwater.à Thiscausesevenwarmerseas.

3) Warmingtemperaturesareleadingtothereleaseofmethane– apowerfulgreenhousegas – fromtheseabedandmeltingtundra,wetlandsandlakesintheArctic.

4) Thesechangescouldpotentiallyimpactglobalweatherpatternsandoceancirculation.

2)Glaciers/icebergs/iceshelves:

• Frozenfreshwateronland

• Contains79%oftheworld’sfreshwaterreserves

• Meltingicecaps/glacierscancause:araisesealevels,alossoffreshwaterreserves,causeadecreaseinsalinityanddensityofthewaterinoceans

2 Types of Frozen Water:

What if all the ice melted?

– WhathappenstosealevelsifSeaIcemelts?

– WhathappenstosealevelsifGlaciers melt?

– Forreference:https://www.youtube.com/watch?v=b6CPsGanO_U

Sea Level Rise - Why do we care if the oceans levels rise?– http://geology.com/sea-level-rise/