An ocean .There are five types of ocean HYDROSPHERE INTRODUCTION It consist of lakes , rivers , seas and ocean Nearly 2.5% fresh water, 9 7.5% salt water .A vast stretch of water is called An ocean .There are five types of ocean Pacific ocean ,Atlantic ocean ,Indian ocean ,Arctic ocean and Antarctic ocean.

PRESENTED BY , RAKESH.P NAGALINGA RAJ URS BIBIN .B

CONTENTS 1. PACIFIC OCEAN . 2. ATLANTIC OCEAN . 3. INDIAN

PACIFIC OCEAN . Pacific Ocean, largest and deepest of the world's four oceans, covering more than third of the Earth's surface and containing more than half of its free water. It is sometimes divided into two nominal sections: the part north of the equator is called the North Pacific; the part south of the equator, the South Pacific. The name Pacific, which means peaceful, was given to it by the Portuguese navigator Ferdinand Magellan in 1520.

ATLANTIC OCEAN . Atlantic Ocean, the second-largest of the Earth's four oceans and the most heavily travelled. Only the Pacific Ocean is larger. The Atlantic is divided into two nominal sections: the part north of the equator is called the North Atlantic; the part south of the equator, the South Atlantic. The ocean's name is derived from Atlas, one of the Titans of Greek mythology.

INDIAN OCEAN . Indian Ocean, the smallest of the Earth's three great oceans, located mainly in the Southern Hemisphere, and bounded on the west by Africa, on the north by Asia, on the east by Australia and the Australasian islands, and on the south by Antarctica. No natural boundary separates the Indian Ocean from the Atlantic Ocean, but a line about 4,020 km (2,500 mi) long on the meridian 20 ° east, connecting Cape Agulhas at the southern end of Africa with Antarctica, is generally considered to be the boundary.

ARCTIC OCEAN Arctic Ocean, body of water variously identified as the smallest of four world oceans or as a virtually landlocked arm of the Atlantic Ocean. The Arctic Ocean extends south from the North Pole to the shores of Europe, Asia, and North America.

ANTARCTIC OCEAN . Southern Ocean or Antarctic Ocean, southernmost parts of the Atlantic, Indian, and Pacific oceans. Its northern boundary has been set at latitude 55° south, the Antarctic Convergence Zone, giving it a total area of 32,248,000 sq km (12,448,000 sq mi). Drake Passage, south of Cape Horn, is the narrowest part of the ocean. A large part of the Southern Ocean is covered by the ice shelf that surrounds Antarctica. Most of the continental shelf is under this ice. The rest of the ocean is deep, with four especially deep basins in it, separated by submarine ridges.

IMPORTANCE OF OCEAN . Ocean is the store house of many renewable resources . Petroleum , salt , manganese , cobalt , pearls and fish are available in plenty in the oceans . Fish is very valuable . It is a source of food and nutrition . The evolution of life took place in the oceans. So the smallest creatures like bony fish and largest creatures like the blue whale are found in oceans .The oceans are regarded as huge museums with a variety of creatures . The oceans are also natural highways for trade and communication for many countries of the world . Due to the oceans , many countries enjoy maritime climate throughout the year . The summers are cool and winters are mild . Evaporation takes place in these oceans , clouds are formed and rain occurs . This entire hydrological process is due to the oceans . Man has explored new sea routes through oceans . Waves , tides and ocean currents help people to generate alternate energy .

DEPTH OF THE OCEANS. Depth of the oceans was measured using ropes and wires . Now echo-sounding In 19th century device and Bathythermographs are used . Fathom (6 feet –1 fathom ) is a measuring unit. With the help of it , depth of oceans is divided into five zones. 1. Continental shelf . 2. Continental slope . 3. The ocean deeps . 4 . Deep sea plain . 5 . Sea mounts .

CONTINENTAL SHELF . It is submerged coastal land . It is formed by the deposition of materials brought by rivers and waves . CONTINENTAL SLOPE . It is relatively steep . The angle is three to seven degrees . It covers 15% of the total area of the oceans .

THE OCEAN DEEPS . The ocean deeps cover only 1.2% of the sea floor . These are formed due to volcanoes and faulting of the earths crust . DEEP OCEAN PLAINS . The ocean plains are more extensive than the plains on land surface . They occupy more than 82.7% of the total area of the ocean floor . SEA MOUNTS . There are thousands of sea mounts on the ocean floor . They are flattened by erosion . They are known as ‘GUYOTS’.