The document outlines oceanography, detailing the significance of oceans as vital ecosystems covering 70% of the Earth's surface and hosting diverse marine life. It discusses the five major oceans, their geographical characteristics, and the interconnectedness with climate regulation and human survival. Various branches of oceanography, including physical, chemical, biological, and geological oceanography, are highlighted, emphasizing their interdisciplinary nature and the tools used by oceanographers to study these environments.

1. OCEANOGRAPHY-
An Outline
By
Prof. A. Balasubramanian
Centre for Advanced Studies in Earth
Science,
University of Mysore, India

2. When we look at
the world map
we see two distinct features as
1)Continents as land frontiers
2)Oceans as large waterbodies
We also can see that the oceans
covermore surface area than the
continents.

3. Oceans are Marine
ecosystems
• Contain 97 % of all the water
available on earth. But it is
mostly saline. Unlike continents
which are mostly detached from
each other, oceans are well-
connected watermasses.

4. Origin of life
• It is a fact that life initially
originated in saline waters on
earth .

5. • The World ocean covers about 70%
of the Earth’s Surface.
• Most of them lie in the Southern
Hemisphere, i .e., south of the
equator.
• The Southern Hemisphere consists in
area about 80% ocean and the
Northern Hemisphere about 60% of
the ocean.
Area of coverage by the
Oceans

6. • Due to this reason, the
• Southern hemisphere is called
as WaterHemisphere and
• the Northern Hemisphere is
called as Land Hemisphere.

7. • Oceans constitute the most important
part of ourphysical environment.
• Ocean wateris saline, dense and
dynamic.
• It is characterized by various types
of horizontal and vertical
movements, such as tides, waves
and currents.
• Any change in sea-level has a great
influence on the land masses.

8. Oceans are rich treasures
• Oceans are full of various kinds of
vegetation and organic life.
• Some of them are very small ortiny
and some of them are large animals.
• Marine food resources are unlimited.
• Fisheries are inevitable aspects in
human survival.

9. • Huge volume of Mineral matter
are deposited in ocean bottoms.
• It is estimated that 40 pounds of
gold and 200 pounds of lead are
present in dissolved form in
every one cubic mile of ocean
water.
• Vast resources of petroleum, coal
and natural gas lie buried deep
below oceans.

10. Oceans &Seas
• Sources forfood, energy and
mineral deposits.
• Swimming, Sailing and recreation
are also done in these systems.
• Ships navigate through these
oceans to carry cargo between
continents.

11. Controlling Global Climate
• One can not learn about the
weatherwithout considering the
ocean and its effects on
controlling it.
• The global climate is maintained
by these large watermasses,
otherwise, the earth would be a
hot and arid wasteland.

12. • Ocean has the ability to absorb,
store, and release heat into the
atmosphere.
• The Top 10 feet of the ocean surface
contains more heat than ourentire
atmosphere.
• Majorclimatic events like El Nino,
result from ocean temperature
changes. These changes have
impacts on the weatherevents such
as hurricanes, typhoons, floods and

13. More habitat is seen
nearthe seas
• More than One-half of the
world’s population lives
within 100 km distance
nearthe coastlines/oceans.

14. World Oceans
The Continents divide the world’s
oceans into five majorparts as
1.The Pacific Ocean
2.The Atlantic Ocean
3.The Indian Ocean
4.The Arctic Ocean
5.The Antarctic Ocean

15. •Each ocean includes
smallerbodies of water
called as seas, gulf and
bays.

16. The Pacific Ocean
• Is the largest of the world’s
oceans.
• Covers about 181 million
sq.km. It is also the deepest
ocean with an average depth
of 3940 m. Contains half the
waterin the world oceans.

17. The Pacific Ocean
• Stretches about 24000 km
from Panama to the Malay
Peninsula. North and South
America borderthe Pacific on
the east and Asia and
Australia lie to the west.

18. The Atlantic Ocean
• Covers about 94 million sq.km
excluding the waters of the
Arctic.
• Europe and Africa lie to the east
of the Atlantic and north and
South America lie to the west.
• It is the shallowest ocean with an
average depth of 3580 m.

19. The Indian Ocean
• Has an area of about 74 millionHas an area of about 74 million
sq.km.sq.km.
• Africa lies to the west.Africa lies to the west.
• Australia and Indonesia lie to theAustralia and Indonesia lie to the
east.east.
• Asia borders the Indian Ocean onAsia borders the Indian Ocean on
the North.the North.
• The average depth is 3840 m.The average depth is 3840 m.
• It is the Indian ocean which bridgesIt is the Indian ocean which bridges

20. The Arctic Ocean
• It is the smallest ocean in the
world.
• It covers about 9.5 million sq.km.
• It lies north of Asia, Europe and
North America.
• North Pole is nearthe centre of it.
• It is a frozen sea throughout the
year.
• It is the shortest airroute between

21. The Antarctic Ocean
• Is the name given to the waters
surrounding the Antarctic Continent.
• A mixerof the three majoroceans.
• Contains 150 to 300 m thick icebergs
• Constant temperature of -2 Deg. C.
• Surface freezes in winter and breaks
into pack ice in summer.

22. Notable Seas
• Red Sea
• Mediterranean sea
• Arabian Sea / Bay of Bengal
• Persian Gulf
• Baltic Sea / Bering Sea
• Hudson Bay
• Marginal Seas

23. Understanding the
Oceans
• Requires a basic knowledgeRequires a basic knowledge
of geological, chemical,of geological, chemical,
physical and biologicalphysical and biological
processes and how theyprocesses and how they
interact in different parts ofinteract in different parts of
the ocean environment.the ocean environment.

24. Oceanography
• The subject of studying the
physical, chemical and biological
conditions of oceans is called as
Oceanography.
• It is an inter-disciplinary subject
and an emerging area formarine
engineering. It is the science of

25. Oceanography
• Is a science concerned with the
physico-chemical characteristics of
oceanic water, its depth, temperature,
salinity, movements like tides, waves
and currents, flora and fauna found at
various zones of seas and oceans.
• As it deals with the distribution and
processes of these waterbodies, it
comes underearth sciences in

26. Oceanography is a part of
the subjects like
• Physical Geography
• Marine biology
• Marine geology
• Fishery biology
• Marine Engineering
• Marine Geophysics

27. Oceanographers
• Are the scientists who study these
aspects in a detailed way.
• They use several types of
instruments on research ships.

28. Oceanographers
• Operate underwatercameras to
photograph the sea floor.
• They use echo sounders to
measure the depth of water
column.
• They also use some special
devices to collect watersamples
in seas at different depths.

29. Today
• People use satellites and satellite
data to analyse ocean dynamics.
• GPS and GIS tools are fully used by
them.
• Use of submersibles enable them to
observe the features of sea floors.
• Exploring the oceans is a challenging
and adventurous activity to all
scientists, engineers and mariners.

30. Divisions of
Oceanography
1.Physical Oceanography
2.Chemical Oceanography
3.Biological Oceanography
4.Geological Oceanography
5.Marine Biology
contd..

31. Divisions of
Oceanography contd..
6. Applied Oceanography
7. Marine Meteorology
8. Palaeo-oceanography

32. 1. Physical Oceanography1. Physical Oceanography
• Study of physical properties andStudy of physical properties and
dynamics of the ocean. Describesdynamics of the ocean. Describes
the physical processes influencingthe physical processes influencing
the oceans and coastal regions,the oceans and coastal regions,
• The interaction of the ocean with theThe interaction of the ocean with the
atmosphere. The distribution ofatmosphere. The distribution of
oceanic winds, currents, heat fluxesoceanic winds, currents, heat fluxes
and watermasses.and watermasses.

33. 1. Physical Oceanography
• Physics of the Ocean,
• Oceanographic Exploration,
Evolution of scientific concepts
• Physical setting of seas and oceans-
dimensions, sea-floor, bathymetry,
databases.
• Sound in oceans
»Contd..

34. 1. Physical Oceanography …
contd
• Atmospheric influences, wind
systems, wind stress.
• Oceanic Heat Budget, fluxes, heat
transport.
• Temperature, Salinity and Density
• Light in the ocean and absorption of
light
Contd..

35. 1. Physical Oceanography …
contd
• Dominant forces forocean dynamics-
types of flow in oceans, conservation
of mass and salt
• Equations of motion with continuity-
viscosity, turbulence, mixing,
stability concepts.
Contd…

36. 1. Physical Oceanography …
contd
• Response of the upperocean to
winds. Geostrophic currents-
hydrostatic equilibrium. Wind
driven ocean circulation- ocean
waves.
• Vorticity and Deep circulation in the
ocean. Equatorial processes, El Nino
effects. Mathematical models.
• Tides and coastal processes.

37. 2. Chemical Oceanography
• Is the study of everything about the
chemistry of the ocean
• distribution and dynamics of the
elements, isotopes, atoms and
molecules.
• This ranges from fundamental
physical, thermodynamic and kinetic
chemistry to two-way interactions of
ocean chemistry with biological/

38. 2. Chemical Oceanography
….contd
• Interactions between oceans,
lithosphere, atmosphere and
biosphere
• Sea waterchemistry
• Controls in Chemical distribution
• Components of marine sediments
• Chemical controls in biological
production Contd…

39. 2. Chemical Oceanography
….contd
• Temperature, salinity of sea water
• Density structure &Ocean Circulation
• Majorions and dissolved gases in
water
• Nutrients, Conservative elements,
gas exchange
• Mass-balance, residence time,
processes

40. 2. Chemical Oceanography
….contd
• Ocean’s Biological carbon Pump
• Sediment traps/ocean carbonate
system
• Oxygen mass-balance, Chemical
equilibrium and solution chemistry-
free energy of reactions, Acids and
bases, Deep ocean fluxes, Redox
chemistry, hydrothermal circulation
• Chemical tracers, radionuclides .

41. 3. Biological
Oceanography
• Basic ecological concepts are central to
many studies of biological oceanography
• Study of marine life, habitat, interactions
• Abiotic Environment
• Phytoplankton and primary production
• Zooplankton, migrations and changes
• Energy flow &mineral cycling
Contd…

42. 3. Biological Oceanography
….contd
• Marine Food Chains, Food Webs
• Nektons, marine reptiles, mammals
• Seabirds, Mariculture
• Benthic plants and animals
• Inter-tidal environments, beaches
• Coral Reefs, Estuaries, mangroves
• Deep sea ecology, marine pollution
Contd…

43. 4. Geological Oceanography
• Basic Concepts- lithosphere &
hydrosphere
• The oceanic crust, continental
margins, ocean bottom relief, ocean
basins
• Oceanic ridges, rift-valleys, Island
Arcs
• Sea water, marine sedimentation

44. 4. Geological Oceanography
….contd
• Factors affecting ocean circulation
• Waves and currents, tides and
energy Coastal erosion and drifting of
sediments
• Sea level changes, depositional
environments, marine deposits
• Oil-Traps and energy sources
• Tectonic movements- underwater

45. 5. Marine Biology
• Study of the life in marine waters
• Ecosystem components
• Energy flow, productivity, trophic
levels
• Fishery biology, aquaculture,
mariculture
• Growth and biological process
• Forms, communities, migration, etc

46. 6. Applied
Oceanography
7. Marine Meteorology
8. Palaeo-oceanography

47. Marine Engineering

48. Marineexploration

49. Applied aspectsin
oceanography

50. Thank You