GGR202H5 Lecture Notes - Lecture 93: Littoral Zone, Intertidal Zone, Neritic Zone
Document Summary
Chapter 12: oceans: 70% of earths surface, mean depth 3. 8km (absolute darkness, extremely poorly studied, nasa"s budget exceeds noaa"s by 1,600x. Ocean water: not just h2o: 96. 5% water ions of dissolved salts; dissolved gases, oxygen (photosynthesis, bacterial metabolism, atmospheric diffusion, major reservoir for co2, gases are vertically stratified. Surface: warmed by sunlight and stirred by wind; water density friction of wind allows new water molecule to be exposed and release heat. Deeper: thermocline = temperature , halocline = salinity (generally, pycnocline = density . Deep zone: dense, cold, sluggish water, unaffected by winds, storms, sunlight. Plankton = floaters subject to ocean currents. Very dynamic = tectonic plate movements occur. Vertical and horizontal flows: upwelling = upward flow of cold, deep water where winds blow away from, or parallel to, coastlines, bring nutrients, downwelling = oxygen-rich water sinks where surface currents come together. Surface currents are driven by wind, through friction.
