Geo Perspective

* Ocean circulation – water in constant motion due to wind (surface currents) or thermohaline circulation (driven by heat & salinity)
  * Oceans & coastlines are constantly changing as a result of plate tectonics, wave action, sedimentation, and human activity
  * Bathymetry-the measurement of the depth to the ocean floor and mapping of its features
  * Elevation of the ocean surface varies: masses of rock on the sea floor exert gravitational pull mound of water
  * 4 major depth zones = continental shelf, abyssal plain, oceanic ridge, oceanic trenches
  * passive margin zones: continental shelf, continental slope, continental rise, abyssal plain (no trench)
  * active margin zones: continental shelf, continental slope, trench, abyssal plain (no continental rise)
  * oceanic ridges: ocean floor rises from the abyssal plain to the ridge, 90% of Earth’s volcanic activity happens at ocean ridge, doesn’t heat the water, ocean depth – 3km, adjacent to ridge-region of submarine hot springs
  * oceanic trench:active continental margins, convergence, form a trench near the subduction zone, narrow & deep-deepest place on Earth
  * oceans are “salty” because seawater contains dissolved salts and minerals, most of the dissolved solids in seawater is common salt (NaCl)
  * salinity=measure of the concentration of salt in sea water, water with more salt has higher density
  * salinity is influenced by temp, circulation, precip, fresh water input
  * salinity is highest where temp is high & precip is low (evaporation leaves behind salts)
  * solar energy raises the temp of the ocean, more heat abailable in the tropics than near the poles, highest average annual ocean temp are found along the equator (81 degrees F)
  * water can absorb a lot of thermal energy, the density of water decreases with increasing temp, warm water is less dense than cold water
  * water has a high specific heat (amount of thermal energy required to... [continues]

Read full essay