CHAP. 2 CHEMICAL FACTORS

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CHAP. 2 CHEMICAL FACTORS

• PGS. 33-37 AND 40-55

ACTIVITIES- Ice Coring Sample, Thermal
Stratification, Geological Time Scale
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I. PROPERTIES OF WATER

• A. hydrogen bonds- holds molecules together with
  weak chemical bridges
• polar molecule
• high heat capacity
• viscosity thickness
• surface tension

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B. density- mass/vol. provides buoyancy

• expansion of water at 0ºC
• temperature influences density

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Bond width expands
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II. COMPOSITION OF SEA WATER

• dissolved inorganic particles (salts)
• dissolved organic (nutrients)

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• dissolved gases
• suspended particles

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A. salts NaCl

• Principle of Constant Proportion
• (see handout)
• ions per 1000 g of water
• Cl, Na, S, Ca, K 99
• 86
• salinity 1.8050 x chlorinity

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B. Dissolved gases

• O2, CO2 ,N2
• fig. 2-7 in text

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B. Dissolved gases

• O2, CO2 ,N2
• fig. 2-7 in text
• Gas is more soluble in cold water
• O2 enters from the atmosphere and photosynthesis
• Anaerobic without oxygen

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III. THERMAL STRATIFICATION

• water layered by temperature- 250 C to 40C
• Thermocline - narrow region of rapid temperature
  change

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Spring Turn over SUMMER
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Spring Turn over FALL
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Spring Turn over WINTER
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Spring Turn over SPRING
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• Nutrients are brought up from the bottom
• Oxygen is carried down to aid in aerobic
  respiration

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IV. LIGHT ABSORPTION

• 65 of light is absorbed in the first meter
  "heats water"
• colors are selectively absorbed
• absorption depends on suspended particles in the
  water

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Why is the ocean BLUE?

• colors are selectively absorbed by the water
  molecules

• RED LIGHT penetrates the least

• Blue light penetrates the furthest

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• 
  
• absorption depends on suspended particles in the
  water
• Reflection of light occurs too!
• Each area has its own absorption and reflection
  profile
• estuaries,
• open ocean
• continental shelf

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V. BUFFERING

• the ability of a liquid to resist pH change with
  the addition of acid
• pH scale 1-14 log scale
• sea water typically 7.5-8.4
• CO2 is the main influencing agent on pH
• Large amounts of CO2 can be stored in sea water
  because it is converted into other compounds

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Test Topics for Thursday

• Ocean chemistry
• Properties of water (polarity, density changes,
  viscosity, shape of molecule, etc)
• Distribution of components
• -be able to draw graphs (light, temp, oxygen)
• Geological time scale (Era names and dates)
• important marine events
• Be able to explain the results from lab
  activities- density and temperature driven
  currents
• Chap 2 text PGS. 33-37 AND 40-55

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Geological Time Scale
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Nonconformity in the Grand Canyon - Sediments
deposited over Schist
JUST ADMIRE THE PICTURE
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Names are given to times in the past that have
been marked by a significant change in the
fossil and rock record
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Correlation of rock layers

• Matching strata of similar ages in different
  regions is called correlation

http//www.uwsp.edu/geo/faculty/ozsvath/images/str
atigraphy.jpg
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Geologic Timescale
Homework Learn Timescale.doc less Epochs
Divisions based on fossils Eon, Era, Period, Epoch
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Origin of Period Names