By Jessica Tancordo

Geography  covers 360 million km 2  3 major ocean basins  Pacific-180 million km 2  Atlantic-106 million km 2  Indian-75 million km 2

Structure

Temperature Sunlight absorbed Kinetic state Temperature Thermal stratification - layering of water by temperature which is a permanent feature of tropical oceans Thermocline - a layer of water in which temperature changes rapidly with depth Lowest average temp: C Highest average temp: 27 0 C Temperate zone at 40 0 Latitude- greatest stability at 100 m deep

Current What does it transport?What does it do?  nutrients  oxygen  heat  organisms  Gyres – circulation systems move to right of N. Hemis and left of S. Hemis  Upwelling – wind blows surface water offshore allowing colder water to rise to surface  Moderate climates  fertilizes the surface waters off continents  stimulate photosynthesis  promote gene flow through populations

Chemical Conditions  Salinity varies with latitude among seas.  Lowest salinities – near equator and above 40 0 N latitudes- precipitation high & evaporation low  Highest salinities – subtropics- precipitation low and evaporation high  Varies in small enclosed basins  Baltic and Red Sea  Oxygen increases at surface and decreases with depth

Biology  Phytoplankton – microscopic photosynthetic organisms that drift with current  Zooplankton – small animals that drift with current  Ranges from brightly colored organisms in epipelagic zone to bioluminescent organisms in the abyssalpelagic zone  Nourished by organic matter provided by photosynthesis at surface.

Biology continued  The deep ocean refered to as “Biological Desert”  ¼ total photosynthesis in biosphere  Provides substantial amount of global carbon and oxygen.  Little that can be harvested economically for direct human consumptions in the open ocean.

Human influences  Whale populations  Harvesting krill  Dumping of wastes  Strandings  Organisms swallowing and getting caught in trash  Decrease in global carbon and oxygen  Overfishing affects other populations of others.

Why does the Baltic sea have low salinity?  A) It receives freshwater from temperate and boreal biomes  B) it has high precipitation  C) it has low evaporation  D) all of the above

What is Thermocline?  A) a layer of water in which temperature changes rapidly with depth  B) layering of water by temperature which is a permanent feature of tropical oceans.  C) when your thermostat is at your fathers desired temperature.  D) none of the above