The Oceans Chapters 13 & 14 - The Oceans, Waves, Tides & Currents More than 70% of Earth’s surface is covered by water. Pacific – largest & deepest Atlantic – ½ the size of the Pacific Indian – third largest Southern – surrounds Antarctica – South Pole Arctic – smallest – mostly frozen – North Pole - shallowest BavDg&feature=share&list=PL360BF origins of the oceans 4 min 4 min Five Oceans

The Ocean Floor Continental Shelf – starts at the shore and slopes gently into the ocean Continental Slope – begins at the edge of the shelf and continues to the flatter part of the deep ocean floor. Ocean Basin – the part of the Earth covered by ocean. Continental Margin 2 min the ocean floor

The Abyssal Plain Most of the ocean floor is a huge, dark, flat region know as the abyssal plain. Covered in mud with the remains of animals One of the flattest places on Earth. = 2 ½ miles Deep-Ocean Basin 8 ½ min deep ocean

Ocean Trenches An ocean trench is a large, V-shaped valley. Formed by two oceanic plates pushing into one another and the heaviest plate forced under the other plate. Trenches are the deepest places in the oceans. Deep-Ocean Basin 6 min Formation of the Mariana Trench

Mid-Ocean Ridges Mid-ocean ridges are underwater mountain ranges. Longest mountain chain on Earth – 40,000+ miles Form on the ocean floor where two plates pull apart and magma comes up to form the mountains. Deep-Ocean Basin 3 min Mid-Atlantic Ridge

Mid-Ocean Ridges Where the two tectonic plates pull apart, a rift valley is formed between the ridges of mountains. In the Atlantic Ocean, the rift valley is miles wide. New crust is formed in the rift valley. Iceland was formed from a mountain within a mid-ocean ridge. Deep-Ocean Basin

Seamounts Underwater mountains that are far away from mid-ocean ridges are called seamounts. Form when melted rock below the crust pushes it way through the ocean floor and cools. Volcanic islands formed from seamounts - Hawaiian Islands – Cape Verde Islands (off coast of West Africa) Deep-Ocean Basin 3 min Seamounts

Ocean Composition Microscopic organisms that float or drift freely near the ocean’s surface are called plankton. Phytoplankton – plant-like Zooplankton – animal-like 6 min plankton

Ocean Composition Ocean water is salty. Surface water washes over rocks in rivers and stream dissolving sodium chloride. Sodium chloride is common table salt. Desalination is the process of removing salt from sea water. 3 min Desalination 2 ½ min why is it salty?

Ocean Waves Ocean water is always in motion. A wave is a traveling disturbance that carries energy from one place to another. When wind blows across the water, the wind’s energy is transferred to the water. As a wave moves, it appears to be moving water forward. But in reality, the water is moving up and down. Most waves wash up along beaches. This movement pushes sand along the beach.

Tsunami A giant ocean wave that forms after a volcanic eruption, submarine earthquake, or a landslide is called a tsunami. 6 min - Japan 1 min causes The Day of the Tsunami 20 min

At the shore, the level of the ocean rises and falls during the day. The tide is the rise and fall of ocean water. Tides are caused by the gravitational pull of the moon and Sun. The moon’s gravity causes Earth’s surface water to bulge on the side of the Earth closest to the moon. Most shores have two high and two low tides. 1 min Bay of Fundy, Canada 3 min tides Tides

Currents Another kind of ocean motion. A current is a flow of water in a certain direction. Warm water flows away from the equator. Cold water flows towards the equator. Important current – Gulf Stream (warm ocean current)

Causes of Currents Global winds are the main cause of surface currents. Differences in salinity (saltiness) causes deep currents. Earth’s rotation causes currents to move in a clockwise direction in the northern hemisphere. An undertow is subsurface current near the shore and pulls objects out to sea.

6 min - the deep ocean 2 min - the ocean floor 4 min - deep sea diving under the North Pole 3 min - oceans conservation 4 ½ min. - Vampire Squid 3 min. - desalination Created by M. Brumbaugh TCMS Cool website 2 min – Bay of Fundy 1 ½ min - Bay of Fundy – tides – time lapse 3 min Tidal Bore surfing 10 min Lost Gold – SS Republic