KERALA PSC / PHYSICAL GEOGRAPHY / OCEANOGRAPHY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE

 

KERALA PSC / PHYSICAL GEOGRAPHY / OCEANOGRAPHY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE

KERALA PSC / PHYSICAL GEOGRAPHY / OCEANOGRAPHY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE

·      Hydrosphere – The mass of water that covers about 71% of the earth’s surface. Oceans are the largest single constituent unit of the hydrosphere

·      Average depth of the ocean is about 4 km

·      Oceans contains more than 97% of the total water on the earth

·      The study of various aspects of oceans is called oceanography

·      Oceans predominate over land areas in southern hemisphere

·      With increasing depth the temperature of the ocean water decreases

·      The temperature of the surface waters varies mainly with latitude. The polar seas can be as cold as -2ºC while the Persian Gulf can be as warm as 36ºC

·      Salinity is defined as the total amount of salt particles in grams contained in one kilogram of water and is expressed as part per thousands

·      Salinity is due to the presence of compounds of sodium, potassium, magnesium, calcium and other elements including a high proportion of sodium chloride

·      Salinity affects the physical properties of the oceans such as temperature, density, pressure, currents etc..

·      The average salinity of sea way is 35 part per thousand

·      Peninsula is a piece of land almost surrounded by water. Southern India is a peninsula

·      The sea with the highest degree of salinity is the Dead Sea. No fish live in this sea, hence it is called Dead Sea

·      There are five major oceans each encompassing within it a large number of seas, bays and gulfs. They are the Pacific, the Atlantic, the Indian, the Arctic and the Antarctic or the Southern Ocean.

 

Pacific Ocean

·      This is the largest ocean in the world

·      One-third of the earth is covered by this ocean. It covers an area of 166 million sq.km and has a volume of 696 million cubic km.

·      The outer boundary of the deep ocean-type structure is called the andesite line, so named after the andesite rock that us found only in the ocean bottoms and not on the continents

·      The name ‘Pacific’ was given by Magellan who was the first European to cross it in 1521 to reach Philippines

·      The Mariana Trench in the Challenger Deep of the Pacific Ocean is the deepest point on the earth

·      In shape, it resembles a broad triangle with its apex in the north at the Bering Strait and the base to the south

 

Atlantic Ocean

·      This is the second largest ocean in the world

·      It is the busiest ocean route in the world

·      The Atlantic Ocean separates American continents from Europe and Africa

·      The greatest depth in the Atlantic is Milwaukee depth in the Puerto Rico Trench

·      Bermuda Triangle is located in the Atlantic Ocean

·      Atlantic Ocean has the shape of the English alphabet ‘S’

·      The Atlantic Ocean covers about 1/6^th of the earth’s total surface

·      The Atlantic ocean has the longest submarine ridge, known as Mid Atlantic Ridge. It has two parts, Dolphine ridge in the north and Challenger ridge in the South.

 

Indian Ocean

·      Indian Ocean is the third largest ocean in the world and the only ocean named after a country, India

·      The greatest depth in the Indian Ocean is the Java (Suda) Trench (7725m)

·      Madagascar is the largest island in the Indian Ocean

·      It is small in size and has an average depth of 4000m

·      The two great bays on either side of the Indian Peninsula, namely, the Bay of Bengal and the Arabian Sea belong to the Indian Ocean

·      Indian Ocean is mostly confined to the Southern Hemisphere while in the northern Hemisphere, it extends only to a few degrees of latitude. Due to this fact, the Indian Ocean is often called half an ocean

 

Arctic Ocean

·      This ocean is the smallest and is limited by the continents of Asia, Europe and North America

·      It is 1/12 of the area of the Pacific Ocean

·      It has an average depth of 4000 meters. The deepest part is 6512 meters’ deep

·      The Arctic Ocean is connected to the Pacific Ocean through the narrow Bering Strait and to the Atlantic Ocean through large openings of the Barents Sea, Greenland Sea and numerous straits in the Canadian archipelago

·      This ocean is roughly circular in shape and it surrounds the North Pole

 

Antarctic Ocean (Southern Ocean)

·      The Antarctic Ocean flows in the eastern direction

·      The Antarctica Ocean is the fourth largest among the five main oceans

·      The current, popularly known as West Drift moves the ocean from west to east all around Antarctica. This current mixes the ends of the Pacific, the southern ends of the Atlantic and the Indian Ocean

KERALA PSC / PHYSICAL GEOGRAPHY / OCEANOGRAPHY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE