The Earth’s Oceans A Dynamic System where many physical and chemical changes are taking place!

The World’s Oceans 71% of the surface of the Earth is ocean 97% of all the Earth’s water is found in the oceans The Atlantic, Pacific, and the Indian oceans are the major oceans The Arctic Ocean, Mediterranean Sea, and the Caribbean Sea are part of the Atlantic Ocean The Pacific Ocean is the largest and the deepest Followed by the Atlantic Ocean, the Indian Ocean is deeper

Mapping the Ocean Floor 1872 the Challenger sailed from England, it remained at sea for three and a half years. It used wire to measure ocean depths. The Challenger collected animals and water samples from the ocean floor. It used special thermometers to record temperatures on the ocean floor.

In 1920 the German ship Meteor used sonar for the first time to map the seafloor.

Today the satellite Topex/Poseidon orbits the Earth using side scan sonar to map the bottom of the ocean

Mapping the Ocean Mapping the bottom of the ocean can only be done by indirect methods, such as echo sounding, radar, sonar, and seismographic surveys

Moving Ocean Water Waves are pulses of energy that move through the ocean They carry energy, not matter They begin as wind stirred ripples on the surface of the water The greater the wind, the greater the wave

Wave Formation The height of the wave depends on wind speed, the length of time the wind blows, and the distance the wind blows Increasing any of these can increase the size of the wave

Wave Trivia The highest wave every noted was 34 meters high in 1933 during a wind storm in the Pacific

Wave Characteristics The crest is the highest part of the wave The trough is the lowest part to the wave Wavelength is measured from crest to crest or trough to trough

Waves (cont) Waves are more destructive in the winter Tsunamis is a giant wave caused by earthquakes

Tides These are the regular rise and fall of ocean water caused by the gravitational pull between the moon and the Earth A bulge occurs in the ocean nearest the moon, this is the high tide and in the opposite is the low tide There are two high tides and two low tides a day Spring tides are highest of the high tides higher and the lowest of the low tides and neap tides have the smallest difference between the high and the low tides.

The Ocean Floor Continental margin consist of the continental shelf, continental slope, and the continental rise Continental shelf is the relatively flat area along the edge of every continent: it ranges from almost nothing to 1200 kilometers, the best fishing, large mineral deposits, and petroleum are found there

Continental slope is at the edge of the continental shelf where the sea floor may plunge steeply 4-5 kilometers Marks the boundary between the continental crust and the oceanic crust

Continental rise is the area between the continental slope and the ocean floor It is made of sediments that wash down from the continental shelf Turbidity current carry large amounts of these sediments in masses of moving water, it is like an underwater avalanche

Submarine canyons are deep V shaped valleys cut through the continental shelf and slope

Features of the Ocean Floor

Abyssal Plain Large flat areas on the bottom of the ocean Atlantic and Indian oceans have largest abyssal plains because almost all the worlds major rivers flow into them producing a large amount of sediment deposits in the plains

Seamounts and Guyots Seamounts are underwater volcanic mountains They have steep sides and narrow summits and rise more than 1000 meters above the sea floor When seamounts rise above the surface of the ocean they become islands Guyots are seamounts that do not rise to a peak or have eroded tops

Midocean Ridges Largest mountain ranges on the Earth These are formed where the plates are pulling apart Rift valleys run along the middle of the midocean ridges

Trenches The deepest part of the ocean found along edges of sea floor Long narrow crevices that can be 11,000 meters deep Deepest trench is the Mariana Trench in the Pacific Ocean that is more than 11,000 meters deep

Hydrothermal Vents Openings into the mantle of the Earth where sea water seeps down and returns to the ocean

Reefs Reefs are large masses and ridges of limestone rocks produced by the shells of animals There are three types of coral reefs: fringing reefs touch the shoreline of a volcanic island

Coral Reefs (cont) Barrier reefs that are separated from the shore by an area of shallow water called a lagoon

Coral Reefs (cont) And an atoll that is a ring of coral reef that surrounded an island that has beenworn away or sunk

This is the easy part!!!!!

And you thought the ocean was just for fun!!!!!!!