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Cohesion
sticks to other water molecules
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Adhesion
Sticks to other types of molecules
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Why is the ocean blue?
absorbs red light, reflects blue light.
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Main properties of water:
- Unusual thermal properties
- Unusual density
- high solubility of chemical compounds in water
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Water vapor
independent molecules
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Unusual thermal properties of water:
- High freezing point
- high boiling point
- high heat capacity
- high latent heat
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High heat capacity of water:
- *capacity for a compound to absorb and hold heat
- highest heat capacity on earth
- ammonia higher... but...
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High latent heat of water:
*probably why we have thunderstorms in florida
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Global thermostatic effects:
- moderates temp. of Earth's surface.
- ex. Equatorial oceans(hot) don't boil.
- ex. Polar oceans(cold) don't freeze solid.
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Marine effect:
Oceans moderate temp. changes day/night;
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Density of ice is less than density of water (T/F)
True
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Density of water decreases as temp. decreases in which threshold?
From 4C to 0C.
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Density of water increases as temp. decreases down to 4C (T/F)?
True
-
Dissolved solids reduce the freezing pt of water (T/F)?
True
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Salinity
- total amount of INORGANIC solid material dissolved
- in water (g/kg)
-
Typical salinity
- 3.5% or 35o/oo
- o/oo or parts per thousand (ppt) = grams of salt per kilogram of water
- (g/Kg )
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Brackish (hyposaline)
< 33 ppt
-
-
What is the most abundant chemical in seawater (besides water)?
Chloride
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Adding salts does not change many properties of water (T/F).
False
-
How is salinity measured?
- Evaporation
- Chemical analysis - Titration
- Specific Gravity (w/ hydrometer) (1.028 g/ml)
- Electrical conductivity (Salinometer, CTD)
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Coastal areas salinity varies more
- widely in what ways?
- Influx of freshwater lowers salinity or creates brackish conditions
- Greater rate of evaporation raises salinity or creates hypersaline conditions
- Salinity may vary with seasons (dry/rain).
-
Processes that decrease salinity:
- Precipitation (rain or snow)
- Runoff (river flow)
- Melting Icebergs
- Melting sea ice
-
Processes that increase salinity:
- Evaporation
- Formation of sea ice
-
How are dissolved substances added to oceans?
- River input (primarily)
- Thermal vents
- Volcanic eruptions
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How are dissolved substances removed from oceans?
- Salt spray (minor)
- Subduction at trenches (Geologic processes)
- Biogenic sediments (Biological processes)
- Evaporites (Chemical processes)
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Is the ocean becoming progressively saltier with age?
- The proportion and amounts
- of dissolved solids remain constant. This concept is known as the
- “steady state ocean.“
- Ions are being added to and removed from the ocean at the same rate.
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What does the hydrologic cycle describe?
recycling of water near Earth's surface.
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Processes that add dissolved substances (salinity increases)
- River flow
- volcanic eruptions
- atmosphere
- biologic interactions
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processes that subtract dissolved substances (salinity decreases)
- Chemical at seawater-sea floor interface
- Biologic interactions
- Evaporite formation
- absorption
-
Residence time
Average length of time a substance remains dissolved in seawater.
-
pH of seawater DOES NOT vary slightly with depth
-
What is the function of Carbonate Buffering?
Keeps ocean pH about the same.
-
Carbonate Buffering: describe the process
- H2O + CO2 > H2CO3 > H+ + HCO3
- ‐ > 2H+ + CO3
- 2‐
- Precipitation/dissolution of calcium carbonate (CaCO3) buffers ocean pH (CaCO3 > Ca+ + CO3
- ‐)
- Oceans can absorb CO2 from atmosphere without much
- change in pH
-
Surface ocean varies primarily with latitude (T/F)?
True
-
Polar regions have slightly lower salinity, why is this?
Lots of rain/snow and runoff
-
Mid-latitudes have higher salinity, why is this?
Evaporation and dry weather
-
Equator has slightly lower salinity, why is this?
Lots of rain
-
The surface ocean salinity is NOT variable (T/F)?
False
-
Deeper ocean salinity is the same (T/F)?
True
-
Halocline
rapid change of salinity with depth
-
What is the density of seawater?
1.022 to 1.030 g/cm3 surface seawater
-
How is the ocean layered?
according to density
-
How is the density of seawater controlled?
-
Of Temperature, Salinity, and Pressure, what has the greatest amount of influence on seawater's density?
- Temperature.
- Density increases with decreases temperature.
-
In what region does salinity have the greatest influence on the density of seawater?
Polar oceans where polar ocean is isothermal (same temperature).
-
Density differences cause a layered ocean (T/F)?
True
-
Pynocline
abrupt change of density with depth
-
Thermocline
abrupt change of temperature with depth
-
Properties of a layered ocean
- Mixed surface water
- Pynocline
- Thermocline
- Deep water
- High latitude oceans (Isothermal + isopycnal)
-
Name a few Desalination processes
- Distillation
- Reverse osmosis
-
Attenuation
A process of scattering and absorbing weakened light
-
What does Z I K stand for?
- Z=depth
- I=intensity
- K=constant
-
Scattering
occurs when light is bounced between air and water molecules, dust and other objects.
-
Absorption
occurs when light's electromagnetic energy is converted to heat in the molecules of seawater.
-
Colors are absorb at different rates:
-
Characteristics of sound in the ocean:
- 25x faster than on land
- directionless to humans
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