Exploring the Ocean

• Since ancient times people have studied the ocean such as waters and ocean floor

• It provides food and services, and serves as a route for trade and travel

The World’s Oceans

• 71% of the Earth’s surface is covered by ocean water.

• The oceans contain 97% of the earth’s water.• All the oceans and seas are actually one

continuous body of water.

Oceans

• The oceans are the Atlantic, Pacific, Indian. Arctic and Southern.

• The Pacific Ocean is the largest ocean.• The area and volume of the Pacific Ocean are

greater than the Atlantic and Indian combined.

Seas

• A sea is a part of an ocean that is nearly surrounded by water.

• The Mediterranean, Arctic and Black Sea are really part of the Atlantic Ocean.

Ocean Floor Makeup

• The ocean floor has higher mountains, deeper canyons, and larger flatter plains. Earthquakes occur more often.

• The rocks are very different.• The crust is thinner

Edges of the Continents• The shoreline is a boundary between where the

land and the ocean meet.• The topography of the ocean floor is different

from the topography of the continents

Continental Margin

• The area where the underwater edge of a continent meets the ocean floor is called a continental margin.

• A continental margin consists of a continental shelf, a continental slope and a continental rise.

Continental shelf• The flat part of a continental margin

that is covered by shallow area of the ocean floor that extends outward from the edge of a continent is called a continental shelf.

Continental shelf

• Depth of 130 meters and gets steeper• A continental shelf slopes gently from

the shoreline.• The width of the continental shelf varies.• Large mineral, oil and natural gas

deposits are found here.

Continental Slope

Continental Slope• The steep edge of the continental

shelf • At the edge of the continental shelf,

the ocean floor plunges steeply 4 to 5 kilometers.

• A continental slope marks the boundary between the crust of the continent and the crust of the ocean floor

Continental Rise

• Separating a continental slope from the ocean floor is a continental rise.

• A continental rise is made of large amount of sediments, rocks, plants and animals.

• Sometimes the sediments are carried down the slope in masses of flowing water called turbidity currents, like an underwater avalanche.

Abyssal Plain

Abyssal Plains

• Large, flat areas on the ocean floor are called abyssal plains.

• The abyssal plains are larger in the Atlantic and Indian than in the Pacific due to the deposition of sediments by large rivers.

• The Pacific Ocean has large cracks that trap sediments and result in smaller abyssal plains.

Abyssal Plains

• Abyssal plains close to the continent are made of mud, sand and silt.

• Farther out on the abyssal plains, some of them contain the remains of tiny organisms that form ooze.

• Where ocean life is not abundant, the floor of the ocean is covered with red clay

Plates• Pieces of earths crust along with parts of the upper

mantle are called plates.• The plates move at an average speed of several

centimeters per year-barely faster than your fingernails grow

• This is what shaped the dramatic features of the ocean, such as mountains and trenches

Seafloor Spreading• Mid ocean ridge is along

boundaries of plates that are moving apart or Diverging adding a new strip of rock to the ocean floor

• Magma squeezes up through cracks

• Magma hardens• Seafloor spreading is what

produced our ocean floor• When plates come together or

Converge, one plate sinks under the other

Mid Ocean Ridge

Mid ocean Ridges

• The mid ocean ridges form an almost continuous mountain belt that extends from the Arctic Ocean down through the middle of the Atlantic Ocean around Africa into the Indian Ocean and across the Pacific Ocean , much as the line of stitches winds around a baseball.

• In the Atlantic it is called the mid-Atlantic Ridge and in the Pacific, the Pacific-Antarctica Ridge.

Formation of Mid ocean Ridges

• Mountain ranges on land are formed when the Earth’s crust folds and is squeezed together.

• Mid ocean ridges are areas where molten material from deep within the Earth flows up to the surface and cools and forms new crust.

• Has 2 parallel chains of mountains separated by valley and trenches

Submarine Canyons

• In many areas, submarine canyons cut through a continental shelf and slope.

• They are deep, V-shaped valleys that have been cut in the rock, possibly by turbidity currents.

• The Monterey Submarine Canyon(2000 meters) is deeper than the Grand Canyon.

Rifts

• Running along the middle of the mid ocean ridges between the rows of parallel mountains are deep crevices or rifts.

• Rifts are areas of great earthquake and volcanic activity.

Trenches• Trenches are the

deepest parts of the ocean found along the edge of the ocean floor.

• Is a steep sided canyon in the ocean floor

• The Mariana Trench in the Pacific Ocean contains the deepest spot on Earth- the Challenger Deep.

Mariana Trench• The Mariana Trench is 2, 542 km (1,580 miles) long

(more than five times the length of the Grand Canyon) and 69 km (43 miles) wide

• The Challenger Deep is 11,033 meters (36,201 feet), almost 7 miles

• If Mount Everest, which is the tallest point on Earth at 8,850 meters (29,035 feet), were set in the Mariana Trench, there would still be 2,183 meters (7,166 feet or about 2 miles) of water left above it.

• http://deepseachallenge.com/the-expedition/mariana-trench/• https://www.youtube.com/watch?v=9FYKLS7xjpg

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