coastal
TRANSCRIPT
The Oceans, Coastal Processes The Oceans, Coastal Processes and Landformsand Landforms
OverviewOverview
OceansOceans Coastal SystemsCoastal Systems
ComponentsComponents ActionsActions OutputsOutputs
Biotic Biotic ComponentsComponents
OceansOceans Chemical compositionChemical composition
WaterWater Salts: dissolved ionic compoundsSalts: dissolved ionic compounds
ClCl--, Na, Na++, Mg, Mg2+2+, SO, SO442-2-, Ca, Ca2+2+, K, K++, Br, Br--
Salinity (parts per hundred)Salinity (parts per hundred) Average: 3.5% Average: 3.5% Brine: >3.5%Brine: >3.5%
Areas with high rates of evaporationAreas with high rates of evaporation Brackish: <3.5%Brackish: <3.5%
Areas at the mouths of rivers; estuariesAreas at the mouths of rivers; estuaries
Atmospheric gasesAtmospheric gases NN22, CO, CO22, O, O22
Physical structurePhysical structure
Coastal System Coastal System ComponentsComponents
Solar EnergySolar Energy Atmospheric windsAtmospheric winds
Create ocean Create ocean waveswaves Climatic regimesClimatic regimes
Gravitational EnergyGravitational Energy TidesTides
Characteristics of coastal rockCharacteristics of coastal rock Human activitiesHuman activities TerminologyTerminology
Littoral zoneLittoral zone Shoreline Shoreline CoastCoast
Coastal System Coastal System ActionsActions
Erosion, transport and Erosion, transport and deposition occur deposition occur through the action of through the action of tides and breaking tides and breaking waveswaves
TidesTides Gravity: Moon and SunGravity: Moon and Sun
Tidal powerTidal power Spring tides, neap tidesSpring tides, neap tidesLunar Phases
Tide Tide PredictorPredictor
Lunar PhasesTide Predictor
Lunar PhasesLunar PhasesTide PredictorTide Predictor
Lunar PhasesLunar PhasesTide PredictorTide Predictor
WavesWaves Solar > Wind > WaterSolar > Wind > Water Each wave crest is a pulse of Each wave crest is a pulse of
energyenergy performs the erosive workperforms the erosive work
Wave refraction and coastal straighteningWave refraction and coastal straightening erosiveerosive
Longshore current and beach driftLongshore current and beach drift erosion, transportation, and depositionerosion, transportation, and deposition
Coastal System OutputsCoastal System Outputs Erosional processes and landformsErosional processes and landforms
Rugged, high relief, tectonically activeRugged, high relief, tectonically active wave cut platformwave cut platform
Transport: longshore currents, beachdriftTransport: longshore currents, beachdrift Depositional processes and landformsDepositional processes and landforms
Land with gentle relief, providing sedimentsLand with gentle relief, providing sediments beachesbeaches barrier spitbarrier spit bay barrierbay barrier tombolotombolo barrier islands – often supports vegetationbarrier islands – often supports vegetation
Erosional LandformsErosional Landforms
Depositional LandformsDepositional Landforms
Biological ProcessesBiological Processes Coral reefsCoral reefs
Coral polypsCoral polyps Secrete CaCOSecrete CaCO33
Symbiotic with algaeSymbiotic with algae Specific ecological niche – sensitive to Specific ecological niche – sensitive to
changeschanges 10 – 55 meters depth10 – 55 meters depth 2.7 – 4.0 % salinity2.7 – 4.0 % salinity 1818oo – 29 – 29oo C water temperature C water temperature clear, sediment free waterclear, sediment free water sea-level rise and warming of ocean waters sea-level rise and warming of ocean waters
threatens coral reefsthreatens coral reefs If global trends were to stop immediately, it is If global trends were to stop immediately, it is
estimated that 50% of the world’s coral reefs will dieestimated that 50% of the world’s coral reefs will die
Coastal WetlandsCoastal Wetlands
Salt marshes: Poleward (N or S) of 30Salt marshes: Poleward (N or S) of 30oo latitude latitude Often form in intertidal zoneOften form in intertidal zone Often occur on barrier islandsOften occur on barrier islands
Mangrove swamps: Between 30Mangrove swamps: Between 30oo N and S N and S latitudelatitude Grow on sediment accumulationGrow on sediment accumulation Serve to shelter young fish, important for conservationServe to shelter young fish, important for conservation
VegetationVegetation hydrophytichydrophytic halophytichalophytic
Estimated 40-80% loss over the last 10,000 Estimated 40-80% loss over the last 10,000 yearsyears
IssuesIssues
Oceans poorly understoodOceans poorly understood Humans are still hunter-gatherers on the Humans are still hunter-gatherers on the
oceansoceans We use the oceans as our universal dumpWe use the oceans as our universal dump
Shoreline developmentShoreline development Development occurs on these constantly Development occurs on these constantly
shifting landscapesshifting landscapes Climate changeClimate change
Rising seal levelsRising seal levels Rising ocean temperatureRising ocean temperature
