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Home , Photic zone

I. : the study of the physical characteristics, chemical composition and life forms of the

II. Overview A. Liquid water is incredibly uncommon in the universe 1. Earth is the only planet in our solar system with it 2. Some moons may have it (all unconfirmed) a. Saturn's moon Enceladus (pending Cassini confirmation in 2010) b. Jupiter’s moon Europa 3. Nothing outside of our solar system (Extrasolar) has yet been confirmed to have water B. Size/Scale 1. ~75% of the Earth is covered with water 2. Greater than 97% of this water is contained within our ocean(s) a. Tons more than all ice, groundwater, , water vapor and rivers combined C. Three Major (decreasing order by area, average depth and volume) 1. Pacific 2. Atlantic 3. Indian D. Two Minor Oceans (decreasing order by area, average depth and volume) 1. Antarctic/Southern 2. Arctic E. : landlocked, or largely so, bodies that have been cut off from true ocean 1. Dead 2. Red Sea

III. Composition A. ~96.5% H2O B. ~3.5% Salts (In decreasing order by concentration) 1. Cl (more than half), Na (almost a third) 2. SO4 [Sulfate], Mg, Ca, K, other (together only just one half a percent of total ocean)

IV. Physical Characteristics 1. Continental Margins a. : part of the continent under water, light slope b. Continental Slope: edge of continental shelf, steep slope near vertical 2. Trench: deep narrow valleys that outline continents in areas 3. Abyssal: floor of ocean basin from ridge to continental trench, few feature 4. Ocean Ridge: underwater mountain ridge 5. : completely submerged undersea volcanoes

V. Light and Life A. On land our food webs all return to the Sun 1. Light projects well through water only in the Photic Zone (50 – 100m) 2. a. – minute photosynthetic plants b. – very tiny animals that consume phytoplankton B. Deepwater??? Chemosynthesis, a whole new world with constant new species VI. Current: A mass movement or flow of a fluid substance A. All currents are affected by the Force B. Surface Currents: generally only the upper few hundred meters of sea water 1. Powered by wind 2. Examples a. b. Antarctic Circumpolar Current (strongest in the world) c. North Pacific Drift Current d. California Current C. : Shoreline feature where currents intersect shore and rise from depth 1. Often carry nutrient laden waters 2. Increase the biologic of a region of ocean D. Density Currents 1. More dense waters sink to a lowest level 2. As equal density is added at the same place, create a high pressure 3. Mixes oceans via upwelling, Oceanic Conveyor (Oceanic Conveyor)