CHAP. 2 CHEMICAL FACTORS PGS AND ACTIVITIES- Ice Coring Sample, Thermal Stratification, Geological Time Scale

I. PROPERTIES OF WATER A. hydrogen bonds- holds molecules together with weak chemical bridges polar molecule high heat capacity viscosity = “thickness” surface tension

B. density- mass/vol. provides buoyancy expansion of water at 0ºC temperature influences density

Bond width expands

II. COMPOSITION OF SEA WATER dissolved inorganic particles (salts) dissolved organic (nutrients)

dissolved gases suspended particles

A. salts NaCl Principle of Constant Proportion –(see handout) ions per 1000 g of water Cl, Na, S, Ca, K =99 % 86% salinity = x chlorinity

B. Dissolved gases O 2, CO 2,N 2 fig. 2-7 in text

B. Dissolved gases O 2, CO 2,N 2 fig. 2-7 in text Gas is more soluble in cold water O 2 enters from the atmosphere and photosynthesis Anaerobic= without oxygen

III. THERMAL STRATIFICATION water layered by temperature C to 4 0 C Thermocline - narrow region of rapid temperature change

Spring Turn over SUMMER

Spring Turn over FALL

Spring Turn over WINTER

Spring Turn over SPRING

Nutrients are brought up from the bottom Oxygen is carried down to aid in aerobic respiration

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

Why is the ocean BLUE? colors are selectively absorbed by the water molecules Blue light penetrates the furthest RED LIGHT penetrates the least

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

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 CO 2 is the main influencing agent on pH Large amounts of CO 2 can be stored in sea water because it is converted into other compounds

Test Topics for Friday Ocean chemistry properties of water (polarity, density, viscosity,etc. distribution of components -be able to draw graphs (light, temp, oxygen) Geological time scale (Era names and dates) important marine events Chap 2 text PGS AND 40-55

Geological Time Scale

Nonconformity in the Grand Canyon - Sediments deposited over Schist JUST ADMIRE THE PICTURE

Names are given to times in the past that have been marked by a significant change in the fossil and rock record

Correlation of rock layers Matching strata of similar ages in different regions is called correlation

Geologic Timescale Divisions based on fossils Eon, Era, Period, Epoch Homework Learn Timescale.doc less Epochs

Origin of Period Names