The totality of water surrounding the
Earth, comprising all the bodies of
water, ice and water vapor in the
atmosphere i.e. water held in oceans,
rivers, lakes, glaciers, ground water,
soil, and air.
Atmospheric water vapors
Figure 1. The location of some major global water reservoirs: oceans
and surface water drainage basins (after Ernst, 2000)
THE EARTH’S HYDROSPHERE:
Distribution of Water on Earth
Percent of Total
1,350 x 1015 m3
(Glaciers & Polar Ice)
29 x 1015 m3
LAKES & RIVERS
8.4 x 1015 m3
0.2 x 1015 m3
0.013 x 1015 m3
0.0006 x 1015 m3
4 x 10-5
Volume of hydrosphere
1386 Million km3
Total surface area of Earth= 510 million km2
Oceans= 361 million km2 (71%)
Land = 149 million km2 (29%)
Northern hemisphere= 61%
Southern hemisphere= 81%
Origin of Water (Theories)
argon, Hydroden came to Earth during lava
degassification resulting into Water.
Acid rains to underlying water results to alkali Earth.
Collisions with camets 4-40% of water.
The surface layer of the ocean is known as the
epipelagic zone and extends from the surface to 200
meters (656 feet).
It is also known as the sunlight zone because this is
where most of the visible light exists. With the light
This heat is responsible for the wide range of
temperatures that occur in this zone.
Animals that live in the twilight zone must be able to
survive cold temperatures, an increase in water
pressure and dark waters.
Octopus, squid, and the hatchet fish are some of the
animals that can be found in this zone.
Below the epipelagic zone is the mesopelagic zone,
extending from 200 meters (656 feet) to 1000 meters
The mesopelagic zone is sometimes referred to as the
twilight zone or the midwater zone. The light that
penetrates to this depth is extremely faint.
It is in this zone that we begin to see the twinkling
lights of bioluminescent creatures. A great diversity of
strange and bizarre fishes can be found here.
It is sometimes referred to as the midnight zone or the dark
This zone extends from 1000 meters (3281 feet) down to
4000 meters (13,124 feet).
Here the only visible light is that produced by the creatures
themselves. The water pressure at this depth is immense,
reaching 5,850 pounds per square inch. In spite of the
pressure, a surprisingly large number of creatures can be
Sperm whales can dive down to this level in search of food.
Most of the animals that live at these depths are black or
red in color due to the lack of light.
It extends from 4000 meters (13,124 feet) to 6000 meters
The name comes from a Greek word meaning "no bottom".
The water temperature is near freezing, and there is no
light at all. Very few creatures can be found at these
Most of these are invertebrates such as basket stars and
tiny squids. Three-quarters of the ocean floor lies within
this zone. The deepest fish ever discovered was found in
the Puerto Rico Trench at a depth of 27,460 feet (8,372
This layer extends from 6000 meters (19,686 feet) to
the bottom of the deepest parts of the ocean.
The deepest point in the ocean is located in the
Mariana Trench off the coast of Japan at 35,797 feet
The temperature of the water is just above freezing,
and the pressure is an incredible eight tons per square
inch. In spite of the pressure and temperature, life can
still be found here. Invertebrates such as starfish and
tube worms can thrive at these depths.
Sea Surface Temperature April 06, 2005 derived
from satellite data
-2°C to 40°C
< ±3 dbar
30g/kg to 42 g/kg
0 dbar to 11000
IOC, SCOR and IAPSO, The international thermodynamic equation of seawater 2010: Calculations and use of thermodynamic properties. Intergovernmental
Oceanographic Commission, Manuals and Guides No. 56, UNESCO (English),
196 pp. (2010).
maxi thickness=4000m Antarctica
Permafrosts NE Asia, N Canada, Green land,
What is Groundwater?
Groundwater is water that has drained through surface
layers of soil and rock until it reaches a layer of rock
material through which it cannot pass, or can pass only
This results in the accumulation of water in the rock
layers above this impermeable layer. The water is
stored in gaps in the rock, or between the particles of
which the rock is composed. Rock which retains water
in this way is called an aquifer.
There are 145 large lakes across the globe with an area
of 100 square km
Holding 168 cubic km of water.
Swamps and bogs are widespread across the Earth
with a total area of about 2.7 million square km or
about 2 % of land area.
The most swampy continent is South America.
The soil moisture is an integral part of the
hydrosphere. This water occurs mainly in the top 2
metres of the soil.
Categories of lakes
low food value
full of soil particles
water is usually brown
very clear water
lots of plankton
Antarctica include penguins, skuas, Wilson's petrel,
fulmar and cape pigeons,
Frog, Gar, Catfish, alligators, river dolphin, Turtle
Green Heron catches Dragonfly
The Bacillus stratosphericus - usually found 20 miles above the Earth - is
believed to have been brought to the surface by atmospheric cycling, which
causes evaporated water rise into the stratosphere and then fall again.
December 10 - USA = Steller sea lions threatened
Nature shows that 90 percent of all large fishes have
disappeared from the world's oceans in the past half
century, a result of overfishing.
The Arctic fox is one of nine animals the IUCN says is
threatened by global warming
Vuglinsky, V. S. Hydrosphere structure and its relationship
to the global hydrological cycle. Hydrological cycle, Vol 1,
Shiklomanov, I. A. Forthcoming. World water resources at
the beginning of the 21st century. Cambridge, Cambridge
University Press UNEP.
World Water Assessment Programme (2003) Water for
people, water for life: The United Nations World Water
Development Report. UNESCO - Berghahn Books. Paris