Ocean Facts A dynamic system in which many chemical and physical changes take place Formed over millions of years as precipitation filled low areas on Earth called basins and now covers 70% of the Earth s surface
Ocean facts continued Major mechanism of energy transfer in the oceans, atmosphere, and the earth s interior is CONVECTION CURRENTS! Largest heat storage on earth. Stored heat drives much of the earth s weather and causes the climate near the ocean to be milder than climates that are at the interior of continents. Example: Our daily temperature here verses VA beach temperature
Composition 96.5% Water and 3.5% salt Salts such as: Na, Cl, S, Mg & Ca Salinity: measure of the amount of dissolved solids in seawater Hydrometer: instrument used to measure salinity Desalination: process by which salts is removed from ocean water to make freshwater
Ocean Currents Mass Movement of ocean water Large current systems in the oceans that carry warm water toward the poles and cold water towards the equator. 3 Types Surface Currents: water that moves horizontally powered by wind, current curve due to the coriolis effect
Density currents: movement of water due to differences in density Upwelling: brings cold, nutrient-rich water from the deep ocean to the surface creating areas of rich biological activity
What is El Nino? El Nino occurs when the trade winds slow or stop. Causes a reversal in ocean currents and a build up of warm water off the coast of South America.
Ocean Waves: Rhythmic movement that carries energy through water Generated by wind, as wind speeds increase so does the wave height Breaker: a wave that collapses on the shore
Tides Daily periodic rise and fall of the water level (4x) Caused by gravitational pull of the moon and sun on Earth s water Tidal range: difference between the high tide and water level and the low tide water level Spring vs. neap tide
Tidal Range Example
Ocean Floor Topography of the ocean floor is as variable as the continents. Some features of the ocean floor are related to plate tectonics.
Parts of the ocean floor - Continental Margin (Contintental shelf, Continental slope, continental rise) - Abyssal plain - Mid-ocean ridge - Seamount (underwater volcano) - Guyot - Trench
Shorelines Rocky Sandy beach shorelines Barrier Islands
Oceans are environmentally and Economically important! Important source of food Important source of oxygen (O 2 ) Estuaries, like the Chesapeake Bay, are areas where fresh and salt water mix, producing variations in salinity and wildlife The ocean resources are finite (not that many) and should be utilized (used) with care.
Our impact on the Oceans Human activities effect the oceans Fishing: Effects food webs and reduces numbers of other organisms that relay on our food organisms as prey Polluting the Bay: If we pollute those pollutants no matter how far away or no matter how inland will eventually get to the oceans and effect the ecosystems there as well as our availablity of freshwater in the process. Offshore drilling: Effects benthos (bottom dwelling) organisms as well as if there are spills which usually occur on a small scale it can effect plankton and other microscopic organism s numbers which also negatively impact oceanic food chains. This can also effect us by impacting the fishing industry, cultural issues (Eskimo s in the arctic), and the future ability of the oceans to recover.
Processes taking place in the oceans Photosynthesis: Respiration: process in which oxygen combines with food so the energy in food can be used. Chemosynthesis: process in which bacteria produce food and oxygen by dissolving chemicals
Ocean life zones Plankton: small or microscopic organisms (usually in top layer) Diatoms, Krill Nekton: larger animals which swim (larger animals which swim) Fish, turtles, whales
Benthos: bottom dwellers Corals, Snails, Sea Urchins