Oceanography The Tides Tides are the daily rise and fall of ocean water level caused by the moon & sun’s gravitational pull (mainly the moon) 2 high and 2 low tides occur daily Spring — greatest tidal range because the moon, sun, and Earth are in alignment (full/new moon) Neap — lowest tidal range worldwide; happens during quarter moon phases The Tides

Currents & Weather Current systems are created by the Coriolis Effect and Wind. In the Northern Hemisphere, currents turn clockwise and warm water moves toward the poles and cold water moves toward the equator (convection currents) Sea level can change. Sea level rises when polar ice caps melt and sea level goes down when more ice is created. Waves are generated by the wind The ocean is the largest reservoir of heat…therefore, it drives most of the Earth’s weather systems

Salinity, Element Concentrations, and Density Currents Salinity is the amount of salt in the water. Average salinity is 3.5%. Because of the salt, ocean water is more dense than fresh water. The salt is washed off the continents by runoff & concentrated in the ocean. Concentration of elements in the ocean (contains 70 elements, here are the top 3): 55% chloride (from volcanoes) 31% sodium (from rivers) 4% magnesium Density currents occur when dense seawater moves to a less dense area. Cold water moves to warm areas Water with salt is more dense. Evaporation or the formation of ice may cause the salinity of water to increase. Rainfall & melting of ice causes salinity of water to decrease. http://www.youtube.com/watch?v=r4cX2EPt2zE&safety_mode=true&persist_safety_mode=1&safe=active

Life in the Ocean Species types in the oceans Pelagic Species—live in seawater Benthic species—live on the bottom Phytoplankton – Primary Producers of the Oceanic Food Web Source of energy is sunlight They include diatoms, coccolithophores, cyanobacteria especially synechococcus and prochlorococcus, and dinoflagellates. Overall, they are called algae. Phytoplankton are primary producers because they use solar energy to convert CO2 and nutrients into carbohydrates and other molecules used by life. This is called photosynthesis. Together, they account for about 95% of the primary productivity in the ocean and about half of all primary productivity on earth.

More Oceanography Upwelling occurs when cold water sink and forces the water on the bottom to be pushed to the surface, resulting in cold bottom water rising to fill the gap. This nutrient-rich water provides extreme amounts of food for fish, therefore upwelling areas are known for rich biological activity. Estuaries — areas where fresh water rivers meet salt water areas. The Chesapeake Bay is an example. There are variations in salinity (salt content) and diverse biological life.

Features of Ocean Floor Extending out from a continent's edge is a gently sloping, shallow area called the continental shelf (F).  At the edge of the shelf, the ocean floor drops off in a steep incline called the continental slope (A).  The continental slope marks the true edge of the continent, where the rock that makes up the continent stops and the rock of the ocean floor begins.  Beyond this slope is the abyssal plain (C), a deep, smooth and nearly flat area of the ocean floor.  In some places, deep, steep-sided canyons called trenches (G) cut into the abyssal plain. These indicate a convergent boundary.  A continuous range of mountains called the mid-ocean ridge (D) winds around Earth. These indicate a divergent boundary.  There are mountains on the abyssal plain, too.  Some reach above the ocean surface to form volcanic islands (E).  Others, called seamounts (B), are volcanoes completely under water.

http://www. youtube. com/watch http://www.youtube.com/watch?v=rkAmZadYIY8&safety_mode=true&persist_safety_mode=1&safe=active 5 min http://www.youtube.com/watch?v=HVJNLSwCGHc&feature=related&safety_mode=true&persist_safety_mode=1&safe=active 30min