OCEANIC LithosphereOCEANIC Lithosphere

PREDICT: What percent of the earth is covered in water? What percent is land? Explain your prediction.

PREDICT:What percent of the earth’s water is salt? What percent is fresh? Explain your prediction.

World Ocean Facts

Area(1,000,000

km²)

Volume(1,000,000

km³)

Average Depth

(m)

Maximum Depth

(m)

Atlantic Ocean

82.4 323.6 3926 9200

Pacific Ocean

165.2 707.6 4282 11,022

Indian Ocean

73.4 291.0 3963 7460

Arctic Ocean

14.1 17.0 1205 4300

Features of the Ocean Features of the Ocean FloorFloor

SalinitySalinity

• A measure of the amount of A measure of the amount of dissolved salts in a given amount of dissolved salts in a given amount of liquidliquid

Estuary

•A place where fresh & salt water meet.

shorelineshoreline

• The point where land meets the The point where land meets the waterwater

Continental shelfContinental shelf

• Sloping shelf of land that is made of Sloping shelf of land that is made of the edges of the continentthe edges of the continent

• The continental shelf regions also The continental shelf regions also contain the highest amount of contain the highest amount of benthic lifebenthic life (plants and animals (plants and animals that live on the ocean floor).that live on the ocean floor).

Continental EdgeContinental Edge

• The part of the continental shelf that The part of the continental shelf that begins to angle sharply downbegins to angle sharply down

Continental SlopeContinental Slope

• The steep cliff like drop from the The steep cliff like drop from the continental edge to the ocean floor continental edge to the ocean floor that connects the continental shelf that connects the continental shelf and the oceanic crust and the oceanic crust

• It usually begins at 430 feet (130 It usually begins at 430 feet (130 meters) depth and can be up to 20 meters) depth and can be up to 20 km wide. km wide.

Continental riseContinental rise

• Lower part of the continental slope Lower part of the continental slope which extends to the ocean floorwhich extends to the ocean floor

Abyssal PlainAbyssal Plain

• The broad flat ocean bottomThe broad flat ocean bottom

TrenchesTrenches

• Deepest parts of the ocean created Deepest parts of the ocean created by the undersea rivers and currentsby the undersea rivers and currents

• The deepest one, the Marianas The deepest one, the Marianas Trench in the South Pacific Ocean, is Trench in the South Pacific Ocean, is more than 35,000 feet (10,668 more than 35,000 feet (10,668 meters), or almost 6.6 miles (10.6 meters), or almost 6.6 miles (10.6 kilometers) deep. kilometers) deep.

Mid-Ocean RidgeMid-Ocean Ridge

• A chain of mountains under the seaA chain of mountains under the sea

• The world’s longest mountain range. The world’s longest mountain range. It runs almost unbroken for 40,000 It runs almost unbroken for 40,000 miles.miles.

Rift ValleyRift Valley

• Large crack that runs down the Large crack that runs down the middle of the Mid-Ocean Ridgemiddle of the Mid-Ocean Ridge

SeamountsSeamounts

• An underwater mountain formed by a An underwater mountain formed by a volcanovolcano

• Most Most seamountsseamounts began life as began life as volcanoes formed over hot spots in volcanoes formed over hot spots in the ocean floor. After the crust the ocean floor. After the crust moves off the hot spot, the volcanic moves off the hot spot, the volcanic activity stops.activity stops.

GuyotsGuyots

• Seamounts whose peaks have Seamounts whose peaks have eroded and become a flat surface are eroded and become a flat surface are called called guyotsguyots

• Inactive volcanoes on the ocean Inactive volcanoes on the ocean floorfloor

AtollAtoll

• As the seamount sinks or its peak As the seamount sinks or its peak erodes, the seamount will disappear erodes, the seamount will disappear beneath the water leaving the coral beneath the water leaving the coral ring. This is called an ring. This is called an atollatoll. .