I.I. GeologyGeology

F.F. Geological ProvincesGeological Provinces4.4. Hot SpotsHot Spots

• Stationary locations where magma rises from Stationary locations where magma rises from mantlemantle

• Heat crust, producing volcanoHeat crust, producing volcano• Crust moves over mantleCrust moves over mantle

• Forms chain of volcanoes, seamounts, Forms chain of volcanoes, seamounts, islandsislands

• Hawaiian Islands Hawaiian Islands • Hawaiian RidgeHawaiian Ridge• Emperor SeamountsEmperor Seamounts

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II.II. WaterWater

A.A. PropertiesProperties1.1. PolarPolar

• Water Water molecules molecules attract each attract each otherother

2.2. Hydrogen Hydrogen BondingBonding

• Water tends to Water tends to be “sticky” due be “sticky” due to weak bondsto weak bonds

Fig. 3.1

II.II. WaterWater

A.A. PropertiesProperties3.3. Surface TensionSurface Tension

• Stickiness at the surface due to Stickiness at the surface due to cohesioncohesion• Water surface can support weight of very small Water surface can support weight of very small

organismsorganisms• Air-water interface supports numerous organismsAir-water interface supports numerous organisms

• Microbes in surface filmsMicrobes in surface films

4.4. ViscosityViscosity• Stickiness to objects due to Stickiness to objects due to adhesionadhesion• Objects moving through water drag some water with Objects moving through water drag some water with

themthem

5.5. Changes in StateChanges in State• Fresh water reaches maximum density at 4 Fresh water reaches maximum density at 4 ooCC• Sea water gets denser as it coolsSea water gets denser as it cools• Ice is less dense than liquid waterIce is less dense than liquid water

Fig. 3.3

II.II. WaterWater

A.A. PropertiesProperties6.6. Heat CapacityHeat Capacity

• Water requires an unusually large amount of Water requires an unusually large amount of heat to raise its temperatureheat to raise its temperature

• Energy needed to break Energy needed to break hydrogen bondshydrogen bonds• High High latent heat of meltinglatent heat of melting/fusion/fusion• High High latent heat of evaporationlatent heat of evaporation ( (evaporative evaporative

coolingcooling))• Ocean tends to have a stable temperatureOcean tends to have a stable temperature

7.7. Solvent PropertiesSolvent Properties• Electrical charges on water (polar molecule)Electrical charges on water (polar molecule)

• Help to pull apart molecules held together by Help to pull apart molecules held together by electrical charge (electrical charge (saltssalts))

• Charged Charged ionsions dissociate in water dissociate in water

Fig. 3.5

II.II. WaterWater

B.B. Dissolved SaltsDissolved Salts• Mostly derived from weathering of rocks Mostly derived from weathering of rocks

on land, hydrothermal vents, volcanic on land, hydrothermal vents, volcanic ejecta and precipitationejecta and precipitation

Fig. 3.6

II.II. WaterWater

B.B. Dissolved SaltsDissolved Salts1.1. ConstituentsConstituents• Salinity = salt contentSalinity = salt content

• Usually expressed in ‰ (g per kg)Usually expressed in ‰ (g per kg)• ““Average” sea water ~34.7 ‰Average” sea water ~34.7 ‰

• 33-37 ‰ in open ocean33-37 ‰ in open ocean• higher in enclosed seashigher in enclosed seas• lower in areas with extensive river runofflower in areas with extensive river runoff

• Fresh water < 0.5 ‰Fresh water < 0.5 ‰• BrackishBrackish water – 0.5-17 ‰ water – 0.5-17 ‰

• Six ions make up 98% of total dissolved Six ions make up 98% of total dissolved solids in sea watersolids in sea water

• Most major constituents used by Most major constituents used by organismsorganisms

II.II. WaterWater

B.B. Dissolved SaltsDissolved Salts1.1. ConstituentsConstituents• Rule of Constant ProportionsRule of Constant Proportions

• Salinity may change from place to place, but Salinity may change from place to place, but proportions of major ions remain constantproportions of major ions remain constant

• Makes it easier for marine organisms to Makes it easier for marine organisms to regulate their physiologyregulate their physiology

• Salinity affected bySalinity affected by• EvaporationEvaporation• PrecipitationPrecipitation• Ice formationIce formation

II.II. WaterWater

C.C. PropertiesProperties1.1. DensityDensity

• Determined by salinity and temperatureDetermined by salinity and temperature• Temperature more influential than salinityTemperature more influential than salinity

• Increases with depth where Increases with depth where water columnwater column is stable is stable2.2. Dissolved GasesDissolved Gases

• Most importantMost important• OO22 – Used for respiration, produced by photosynthesis – Used for respiration, produced by photosynthesis• COCO22 – Used for photosynthesis, produced by respiration – Used for photosynthesis, produced by respiration• NN22 – Used as a nutrient in metabolism – Used as a nutrient in metabolism

• Exchanged between ocean and atmosphere (Exchanged between ocean and atmosphere (gas exchangegas exchange))• More soluble at lower temperaturesMore soluble at lower temperatures• Concentrations impacted by biological activityConcentrations impacted by biological activity

3.3. TransparencyTransparency• Penetration of lightPenetration of light• AffectsAffects

• PhotosynthesisPhotosynthesis• VisionVision• BehaviorBehavior

• Spectral attenuationSpectral attenuation

Fig. 3.12

Secchi Disk

Fig. 3.11

II.II. WaterWater

C.C. PropertiesProperties1.1. DensityDensity

2.2. Dissolved GasesDissolved Gases

3.3. TransparencyTransparency

4.4. PressurePressure• Changes predictably with depthChanges predictably with depth

• 10 m = 1 atmosphere (14.7 psi)10 m = 1 atmosphere (14.7 psi)• Affects gas-filled structuresAffects gas-filled structures• Constrains vertical movements of many animalsConstrains vertical movements of many animals

Fig. 3.14

Fig. 3.13

III.III. CirculationCirculation

A.A. Coriolis EffectCoriolis Effect• Affects motion of winds, currents and Affects motion of winds, currents and

tidestides• Caused by rotation of earthCaused by rotation of earth• N. Hemisphere – Deflects motion to rightN. Hemisphere – Deflects motion to right• S. Hemisphere – Deflects motion to leftS. Hemisphere – Deflects motion to left

Fig. 3.18