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 1/6th 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
