ocean currents,tides and waves

By Harsh, Sriram, Karthikeyan, Suchith,Shrirang,Mrinal and Akhil

Ocean Currents

Ocean Currents •Mass of water moving from

one place to another

Importance

•Moves drifting organisms from place to place – plankton

•Carries eggs and larvae of organisms such as fish

Surface CurrentsDeep Water CurrentsWind Driven Vertical Currents (Upwelling)

•Are wind driven currents•Occur at surface•Are horizontal currents•Are caused by the friction

between wind and water

Movement of surface water or currants

• Is the effect that causes moving objects, ex. Surface Currants to veer clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hempisphere

The Coriolis Effect

Gyre•Massive circular system of wind-

driven surface currents caused due to the Coriolis Effect

•Clockwise in the Northern Hemisphere•Anti-clockwise in the Southern

Hemishphere

Deep Water CurrentsTemperature and salinity in oceans

cause water density differences, which inturn cause water masses to rise and fall

Are vertical currantsWhen combined with surface water

results in conveyor belt movement of water around globe

Deep Water Currents

↑ salinity = ↑ density = water mass sinks↑ temp. = ↓ density = water mass floats

Deep Water Currents

Conveyor Belt Movement Of Water

Wind Driven Vertical Currents (Upwelling)

Is a phenomenon that involves the wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water.

The Californian Current Is a Pacific Ocean Current that moves south along the western coast of North America, beginning off southern British Columbia, and ending off Southern Baja

The cold water is highly productive due to upwelling, which brings nutrient-rich sediments, supporting large populations of whales, seabirds and important fisheries.

• It is a Pacific, Atlantic, and Indian Ocean current that flows east-to-west between the equator and about 20 degrees south.

• In the Pacific and Atlantic Oceans, it extends across the equator to about 5 degrees north.

• Is a cold, low-salinity ocean current that flows north-westward along the west coast of South America from the southern tip of Chile to northern Peru

• Sometimes the current is affected by the ENSO event, causing a decrease of the amount of fish often leading to stock crashes and social and economical effects

• It is a warm water current that flows south along the Brazilian south coast to the mouth of the Río de la Plata.

• Is caused by diversion of a portion of the Atlantic South Equatorial Current from where that current meets the South American continent.

• It flows south from the equator to the west wind drift.

• It is the broad, northward flowing ocean current that forms the eastern portion of the South Atlantic Ocean gyre.

• It extends from roughly Cape Point in the south, to the position of the Angola-Benguela Front in the north, at around 16°S

• It is driven by the prevailing South Easterly Trade winds

• It is a wind driven surface current that is part of the North Atlantic Gyre.

• It branches south from the North Atlantic Current and flows southwest about as far as Senegal where it turns west and later joins the Atlantic North Equatorial Current.

• It is named after the Canary Islands

• It is a powerful, warm, and swift Atlantic ocean current

• It originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean

• It is a cold current in the North Atlantic Ocean

• It flows from the Arctic Ocean south along the coast of Labrador and passes around Newfoundland, continuing south along the east coast of Nova Scotia.

• Is an ocean current in the Indian Ocean consisting of warm surface waters

• It flows south along the African east coast in the Mozambique Channel, between Mozambique and the island of Madagascar.

• Is the Oceanic current that flows north along the western Australian coast

• The flow is strong and steady in summer, but is much reduced during the winter months

• Is an ocean current that moves warm water in a counter clock-wise fashion down the east coast of Australia.

• Is the largest ocean current close to the shores of Australia

• Its source is the tropical Coral Sea off the north-east coast of Australia.

• Is a significant Pacific and Atlantic Ocean current

• It flows east-to-west between about 10° north and 20° north.

• Is a slow warm water current.• Flows west-to-east between 40 and 50

degrees north in the Pacific Ocean.

• Is a strong western boundary current in the western north Pacific Ocean.

• It begins off the east coast of Taiwan and flows northeastward past Japan, where it merges with the easterly drift of the North Pacific Current

• Is a cold subarctic ocean current.• Flows south and circulates counterclockwise

in the western North Pacific Ocean

Effects Of Ocean Currents Cold currents make places colder than other places of the

same latitude. Warm currents make places warmer than other places of the

same latitude. Ocean currents also influence rainfall. Winds passing over

warm currents pick up moisture and cause heavy rainfall. Winds passing over cold currents become cool and dry, and

bring hardly any rainfall. There are places where cold and warm currents meet. These

places are rich in plankton. Since fish eat plankton, the place where cold and warm

currents meet are good places for fishing.

Effects Of Ocean Currents Ocean currents also influence navigation. When a ship

travels along a current its speed increases. When a ship travels against a current its speed decreases.

When a ship travels in the sea where cold and warm currents meet a fog is formed, reducing visibility.

• Are the alternate rise and fall in the level of sea water, caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth.

• High Tide is when the level of sea water rises, and moves up the shore.

• Low tide is when the level of sea water falls and water recedes from the shore.

• Most coastal areas experience two high and two low tides per day.

• Is caused when the pulls of the moon and sun act on the same line during full moon and new moon

• High tides are higher than usual and low tides lower

• Is caused when the moon is in the first or third quarter,when the moon,sun and earth form a right angle

• The height of the tide produced by the moon's attraction is reduced by the sun's attraction

• High tides are not as high as usual and low tides not as low

How Are Tides Useful? The rise in water during high

tide allows big ships to enter or leave harbors safely.

During high tide, water rushes up the mouths of rivers. This helps ships to move in and out of river ports.

The saline waters of the sea freeze at a lower temperature than river water does. In cold countries, the sea water rushing in during high tide prevents harbors from freezing in winter.

A disturbance on the surface of water, caused by the rhythmic movement of water particles due to the action of winds

The height of the wave depends on the speed of the wind

A tsunami is a very long wave caused by submarine or coastal earthquakes, landslide or volcanic eruption

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