The

Earth’s Ocean

The ocean covers 71% of Earth’s surface The ocean contains 97% of the water on

Earth The ocean is Earth’s most important

feature The named oceans and seas (Pacific and

Atlantic, Mediterranean and Baltic) are named for our convenience

They are only temporary features of a single world ocean

Average ocean depth is about 4½ times greater than the average height of the continents above sea level

The Earth's oceans are all connected to one another

Ocean

“DEGASSING” >  is the release of a gas that was dissolved, trapped, frozen or absorbed in some material According to this theory, the ocean had its origin from

the prolonged escape of water vapor and other gases from the molten igneous rocks of the Earth to the clouds surrounding the cooling Earth. After the Earth's surface had cooled to a temperature below the boiling point of water, rain began to fall and continued to fall for centuries. As the water drained into the great hollows in the Earth's surface, the primeval ocean came into existence. The forces of gravity prevented the water from leaving the planet.

Origin of the Ocean

“DEGASSING”

Oceans are byproducts of heating and differentiation: as earth warmed and partially melted, water locked in the minerals as hydrogen and oxygen was released and carried to the surface by volcanic venting activity

Structure of the Ocean

The ocean floor seems like a different world. There is no sun light down here. The water is very cold. The pressure of the weight of miles of water above this area would easily crush a submarine. There is almost nothing to eat, and the animals that live here are few and far between

Structure of the Ocean

 

A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics.

Structure of the Ocean

An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m. Lying generally between the foot of a continental rise and a mid-ocean ridge

Structure of the Ocean

Life in Ocean

Life in Ocean

The oceans are full of life. Invertebrates like crabs, starfish and worms roam the sea floors.

Coral grow in large numbers, creating a home for these creatures. All of these animals are called invertebrates, because they don't have a backbone.

Schools of fish roam the depths also looking for a bite to eat. The triggerfish looks for a wandering crab in a reef while a group of tuna pass by. They must stay alert, because the ferocious tiger shark is looking for its prey.

In shallow depths, the plant life flourishes. Sunlight beams down on the different types of algae. These simple plants serve as food for many animals of the sea.

In the deeper parts of the ocean, the

largest animal known is swimming around like giant blue whale,a mammal. A family of dolphins plays nearby, but must beware of the pod of killer whales looking for a scuba diving meal.

Together, these plants and animals make up what we call sea life. Scientists say that life began in the seas, which means that without these creatures, we would not exist.

One way to explore ocean life is by Scuba diving.

Life in Ocean

Ocean Trench

OCEAN TRENCHES are found along the edge of ocean basins. These trenches contain the deepest parts of the ocean, and therefore, the deepest parts of this is wonderful world.

A long narrow ,steep sided depression of the sea floor. 

Earlier known as Sunda Trench ,located in the northeastern Indian Ocean Length of 2,600

kilometres (8,500,000 ft)

Maximum depth of 7,725 metres (25,344 ft)

Is is the deepest point in the Indian Ocean.

Java Trench

It is located on the boundary between the Caribbean Sea. The trench is 800 kilometres (497 mi) long and has a maximum depth of 8,648 metres (28,373 ft) at Milwaukee Deep - which is the deepest point in the Atlantic Ocean.

 Puerto Rico Trench

Is the deepest part of the world's oceans. It is located in the western Pacific Ocean, to the east of the Mariana Islands The deepest spot on Earth which is located in the western Pacific, near Guam is called CHALLENGER DEEP and at a depth of 11305 m below sea level.

Mariana Trench

The is a deep arcuate trench in the South Atlantic Ocean lying 100 km to the east of the South Sandwich Islands.

It is the deepest trench of the Southern Atlantic Ocean, and the second deepest of the Atlantic Ocean, after the Puerto Rico Trench.

 South Sandwich Trench

Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth or the alignment of the Sun and Moon.

Semi-diurnal tide - Some shorelines experience two almost equal high tides and two low tides each day

Diurnal tide -Some locations experience only one high and one low tide each day

Mixed tide - Some locations experience two uneven tides a day, or sometimes one high and one low each day

T I DE S

The very high and very low tides that occur when the sun,moon and earth are aligned and their gravitational fields combine to create a strong tidal bulge.

Spring tides

(low tide) - the relatively small tides that occur when the moon is 90 degrees out of alignment with the sun and earth

Neap tides

Oceans developed a similar temperature layering,but because sea waves and currents stir the surface water

Temperature

Thermocline – layer under the warm layer where the temperature cools rapidly with depth.It extends to a depth of 2 kilometers.

Warm surface layer –constant mixing by waves and currents ,ocean extends from the surface to a depth as great as 450 meters and surface depth is warm

Cold deep layer- beneath the thermocline,the temperature of water here varies from about 1 to 2.5 degrees celcius.Dense water in the ocean depths mixes very little with the surface.

Ocean Division

1. Pacific ocean - the largest ocean and the largest single geographic feature on the planet, accounts for over half of the ocean surface area on Earth. It is also the world’s deepest ocean, with an average depth of 390 m (12, 927 ft or about 2.5 miles). It is located between the Southern Ocean, Asia and Australia and the Western Hemisphere.

2 .Atlantic ocean – is about half of the size of the Pacific Ocean and not quite as deep. The average depth of the Atlantic Ocean is 12, 880 ft (3, 926). It is located between Africa, Europe, the Southern Ocean and the Western Hemisphere.

3. Indian Ocean- • Third-largest ocean and it has an area of 26,469,900 square

miles (68,566,000 sq km). It has an average depth of 13,002 feet (3,963 m) and the Java Trench is its deepest point at -23,812 feet (-7,258 m). It is located between Africa, the Southern Ocean, Asia and Australia.

4.  Southern Ocean In the spring of 2000 discovered as the world's newest and

fourth-largest ocean.Boundaries were taken from the Pacific, Atlantic and Indian Oceans. It has a total area of 7,848,300 square miles (20,327,000 sq km) and an average depth ranging from 13,100 to 16,400 feet (4,000 to 5,000 m).

5. Arctic Ocean World’s smallest ocean with an area of 5,427,000 square miles

(14,056,000 sq km). It extends between Europe, Asia and North America and most of its waters are north of the Arctic Circle. Its average depth is 3,953 feet (1,205 m).

Crest- the highest part of a wave

Trough - the lowest part of a wave

Wavelength – the distance between successive wave crest or (trough)

Wave length – the vertical distance from the crest to the trough of a wave

Ocean waves

It is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters. Weathering occurs in situ, or "with no movement", and thus should not be confused with erosion, which involves the movement of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity.

Weathering and Erosion

When a wave enters shallow water the bottom of the wave drags against the sea floor.this drag compresses the circular motion of the wave into ellipses.In this deformation the upper part moves rapidly than the lower waves.As the front of the wave rises over,the waves steepens until it collapses forward or brakes. Surf – the

chaotic,turbulent waves breaking along the shore.

Seamount – is a submarine mountain ,usually of volcanic origin, that arises 1 kilometer or more above the surrounding of the seafloor.

Mountain in the ocean

Guyot “gee-o”- illiustrated by Arnold Henri Guyot

A flat-topped seamount,formed when the top of a sinking island is eroded by sea waves

Oceanic island- Is a seamount that arises above sea levels

Atoll - is a circular coral reefs that forms a ring of islands around a central lagoon

Atolls vary 1-130 km in diameter and surrounded by deep water of the open sea

Atoll was formed because of the fringing reef that grow along the shore of volcanic island

Bas island sinks,the reef continues to grow upward to form a barrier reef that encircle the island. Finally the island sinks below sea level and the reef forms a circular.

Sea level has risen and fallen reapetedly in geologic past. Coastline have emerged and submerged throughout earth’s history

During the past 40000 years,sea level has fluctuated by 150 meters primarily to response to growth and melting of glacier.

18000 years ago the rapid sea-level rise started 7000 years ago the sea-level began to level off.

Global warming and Sea Level

Global warming causes sea level rise by two mechanism

1- water expands when it is heated,the water molecules move further apart which makes the water take up more space2- warm air temperatures cause glaciers to melt,which adds fresh water to the oceans

The expansion of seawater with increasing temperature is gradual because a smal

l temperature increases causes a

smal sea-level rise

Rising sea level affects some locations and economics.Places with poor coast protection will be flooded.Ex: a 1-meter rise in sea level would flood 17% of the land area of Bangladesh,displacing38 million inhabitants.

Bad effects!

Is a continuous flow of water in a particular direction generated by the forces acting upon this mean flow, such as

 breaking waves, wind, Coriolis effect (a deflection of air or water

currents,caused by the rotation of the earth),  cabbeling,  temperature and salinity differences and tides.

Ocean current

Deep sea current – vertical and horizontal flow of water below a depth of 400 meters in the ocean,caused mainly by gravity Dense water sinks and

flows horrizontally along the sea floor to form a deep-sea current

2 factors cause water to become dense and sinks: > cooling temperature and rising salinity

Surface current

Horizontal flow of water in the upper 400 meters of the ocean,caused by wind blowing over the sea surfaceThe wind simply drag the sea surface along in the same directionGyre- a circular or elliptical current in either water or air.

Thermohaline circulation circulation of water from the deep ocean to shallow ocean and back again to the deep.

Upwelling- a rising ocean current that transport cold water(and nutrients)from the depths to the suraface,

Tidal current- a current channeled by a bay with a narrow entrance or by closely spaced islands ,caused by the rise and fall of the tides.

We couldn't live on this planet without the oceans.The oceans of Earth serve many functions,

especially affecting the weather and temperature. They moderate the Earth's temperature by absorbing incoming solar radiation (stored as heat energy).

The always-moving ocean currents distribute this heat energy around the globe. This heats the land and air during winter and cools it during summer.

The oceans provide a vast surface area for water to evaporate, thus putting moisture in the amosphere so it can rain. No plants or animals (including humans) could survive without rain.

Benefits :

Prepared by:

Danilyn M. OcampoShalina Mae YamatJessa PatanoArvin Kim Ramirez

Submitted to:

Dra.Minerva Alinaya

THANKYOU FOR LISTENING!!!