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Ocean
Definition: An ocean is the largest body of salt water on Earth, covering
approximately 71% of the planet’s surface. Oceans separate continents and
play a critical role in regulating climate, weather patterns, and supporting
marine ecosystems.
Key Characteristics of an ocean
•Extremely vast and deep (e.g., the Mariana Trench is the deepest point)
•Contains salt water
•Influences global weather and climate
•Includes features like waves, currents, and tides
•Rich in marine biodiversity and resources (e.g., fish, oil, gas)
Major Oceans of the World:
1.Pacific Ocean (the largest and deepest)
2.Atlantic Ocean
3.Indian Ocean
4.Southern (or Antarctic) Ocean
5.Arctic Ocean
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Oceanography
Definition:
Oceanography is the
scientific study of the
ocean.
It explores the physical,
chemical, biological, and
geological aspects of
oceans and seas, including
their interactions with the
atmosphere and the Earth's
crust.
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Main Branches of Oceanography
Physical Oceanography
>>Studies ocean currents, waves, tides, and temperature distribution.
Chemical Oceanography
>> Examines the chemical composition of seawater, including salinity, pH,
nutrients, and dissolved gases.
Biological Oceanography
>> Focuses on marine organisms, ecosystems, food chains, and biological
productivity.
Geological Oceanography
>>Studies the structure and composition of the ocean floor, including plate
tectonics, undersea volcanoes, and sediment layers.
Marine Engineering / Ocean Technology
>> Involves the development of tools and technology for exploring and utilizing
ocean resources (e.g., ships, submarines, underwater robots).
What is the Marine Environment?
The marine environment refers to the oceans, seas, and coastal areas,
including all the physical, chemical, biological, and geological components
found within them. It is a complex ecosystem that supports a vast range of
biodiversity and plays a critical role in regulating the Earth's climate, weather,
and life-support systems.
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Ocean
Definition: An ocean is the
largest body of salt water on
Earth.
Size: Vast — it covers about
71% of the Earth’s surface.
Examples: Pacific Ocean,
Atlantic Ocean, Indian Ocean.
Features: Deep, wide, and
contains major currents,
ecosystems, and weather
systems. Oceans connect
continents and support global
climate regulation.
Sea
Definition: A sea is a smaller
part of an ocean, partially
enclosed by land.
Size: Smaller than an ocean
but larger than a bay.
Examples: Arabian Sea, South
China Sea, Mediterranean Sea.
Features: Often located where
the ocean meets land. Seas
may be connected to oceans or
other seas, and they usually
have shallower waters
compared to oceans.
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Bay
Definition: A bay is a body of
water that is partially surrounded
by land and opens into a sea or
ocean.
Size: Smaller than seas and
oceans.
Examples: Bay of Bengal, San
Francisco Bay, Hudson Bay.
Features: Sheltered and often
used for harbors because they
provide calm waters. The Bay of
Bengal is one of the largest bays
in the world.
