The document discusses the structure and distribution of Earth's hydrosphere. It notes that 96.5% of water is found in oceans, with the remaining 3.5% being fresh water distributed between ice (1.762%), groundwater (1.7%), surface fresh water (0.014%), and the atmosphere and soil (0.002%). It also describes the locations of fresh water including rivers, streams, lakes, aquifers, and wetlands. Finally, it discusses the roles of the hydrosphere, cryosphere, and atmosphere in weathering land surfaces and influencing climate through ice ages and global warming.

1. The Structure of Hydrosphere
Muhammad Fahad Ansari
12IEEM14

2. The Structure of Hydrosphere
• Oceans—96.5% of • Fresh water
water found here distribution:
– Ice: 1.762%
• Fresh water—3.5% of – Groundwater: 1.7%
water found here – Surface Fresh Water:
0.014%
– Atmosphere and soil:
0.002%

3. Understanding Where Your Water Is
Located—Oceans and Ice
• What bodies of water hold the largest amount of
water?
– Oceans—the largest bodies of water on Earth (contain salt
water only)
• What features house water as ice?
– Icebergs: a large piece of freshwater ice floating in open
waters
– Glaciers: any large mass of ice that moves slowly over land
– *permanent snow areas also “house” water as ice

4. Fresh Water Locations—Surface Water
• What is the difference between a watershed
and a river basin?
– Both terms describe land that drains into a
river, stream or lake
• River Basin: the term used to describe an area that
drains into a large river
• Watershed: the term used to describe an area that
drains into a smaller river or stream

5. Fresh Water Locations—River Basins and
Watersheds
• Larger river basins are made up of many
interconnected watersheds
– Example: Cape Fear and Neuse River Basins are
made of many small watersheds
• The water in a watershed runs to the lowest
point—a river, stream, lake, or ocean

6. Fresh Water Locations—Rivers, Streams, and
Lakes
• What is a river?
– A large channel along which water is continually flowing
down a slope—made of many streams that come together
• What is a stream?
– A small channel along which water is continually flowing
down a slope—made of small gullies
• What is a lake?
– A body of water of considerable size contained on a body
of land

7. Fresh Water Locations--Groundwater
• What is groundwater?
– The water found in cracks and pores in
sand, gravel and rocks below the earth’s surface
• What is an aquifer?
– A porous rock layer underground that is a
reservoir for water

8. Other Surface Waters
• What is a wetland?
– An area where the water table is at, near or above
the land surface long enough during the year to
support adapted plant growth
• What are the types of wetlands?
– Swamps, bogs, and marshes
• Swamp: a wetland dominated by trees
• Bogs: a wetland dominated by peat moss
• Marshes: a wetland dominated by grasses

9. THE EARTH’S HYDROSPHERE
• The Earth’s liquid water constitutes the hydrosphere.
• The vast majority of Earth’s water is in the oceans (salt
water), with smaller, but geologically important, quantities of
fresh water in lakes, rivers, and ground water.
• The components of the hydrosphere, as well as the cryosphere
(frozen water), the atmosphere, and the biosphere, participate
in the global hydrologic cycle.
• Earth’s water supply has had, since Earth was created, major
influences on Earth’s climate, its landscape and mineralogy, the
composition of its atmosphere, and on the origin and evolution
of life.
– The total mass of Earth’s water is about 300 times the mass of the
atmosphere.
– Without water, which facilitates the formation of carbonate
rock, the atmospheric content of CO2 would be far higher than it
is.

10. THE EARTH’S HYDROSPHERE:
Distribution of Water on Earth
Volume Percent of Total
OCEANS 1,350 x 1015 m3 97.3
CRYOSPHERE 29 x 1015 m3 2.1
(Glaciers & Polar Ice)
UNDERGROUND 8.4 x 1015 m3 0.6
(Aquifers)
LAKES & RIVERS 0.2 x 1015 m3 0.01
ATMOSPHERE 0.013 x 1015 m3 0.001
BIOSPHERE 0.0006 x 1015 m3 4 x 10-5

11. Distribution of Water on Earth

12. The Hydrologic Cycle

13. Typical Elevation Profile of Oceanic Margins

14. Echo Sounders for Measuring Ocean Depths and Floor Profiles

15. The World’s Ocean Floors

16. THE EARTH’S HYDROSPHERE
• The hydrosphere, along with the atmosphere and
cryosphere, are primarily responsible for weathering and
erosion of land surfaces.
• Rain water, in combination with atmospheric CO2, is primarily
responsible for chemical weathering by carbonic acid, H2CO3.
• The amount of CO2 dissolved in the oceans is much larger than
that currently in the atmosphere. Since the solubility of CO2 in
water decreases with temperature, global warming could
produce a positive feedback effect by releasing oceanic CO2.
• Man-made and volcanic pollution can increase weathering by
providing much stronger acids (“acid rain”; e.g. H2SO4), and by
increasing atmospheric CO2.
• Rain, plus the river and stream components of the
hydrosphere, also provide mechanical erosion of rocks and
convert them to soils and sediments.

20. Wave and Underwater Motions

21. Production of Tsunami Waves by Earthquakes

22. LIFE IN THE OCEANS
• Throughout Earth’s history, the oceans have had major
influences on the evolution and propagation of life, and vice
versa.
• Early in Earth’s history, before the advent of photosynthesis on
a large scale, there was no atmospheric ozone layer to protect
life forms on the surface from damaging solar ultraviolet
radiation.
• Therefore, the oceans (and other large bodies of water)
provided the only UV-protected (but visible light illuminated)
habitats for the original procaryotic life forms, as well as
essential nutrients.
• Life forms have also had significant influences on the oceans
and ocean beds, because of their capabilities to convert carbon
dioxide and soluble calcium compounds into limestone (calcium
carbonate, CaCO3).

26. THE EARTH’S CRYOSPHERE
• Earth’s supply of frozen water, the cryosphere, is second only to
the oceans in water content.
• The cryosphere consists mainly of the permanent ice caps of
Antarctica and Greenland, with much smaller amounts in Arctic
and mountain glaciers.
• Major changes in sea level can occur during times of global
climate change (ice ages and global warming), due to
associated changes in the water content of the cryosphere.
• During ice ages, glaciers can cover major parts of Earth’s land
area year-round for hundreds or thousands of years.
• The advance and retreat of glaciers can also produce major
erosion and re-configuration of the landscape.
• Ice ages and global warming can have major effects on the
biosphere as well.

27. Permafrost in Land Areas
• Land areas in polar
regions, such as
Antarctica and
Greenland, and the
north slopes of Alaska
and Siberia, have
zones below their
surfaces in which
ground water remains
frozen year-round.
• Regions in which soil
water is permanently
frozen constitute what
is known as
permafrost.

28. Ice Cover of Greenland and Antarctica

30. Ice Age North Polar Coverage

31. ICE AGES AND GLOBAL WARMING
• The most recent “ice age” ended about 12,000 years ago, which
was prior to the advent of civilized human history.
• It is still unknown as to what causes the advent of ice ages, and
the extent that they occur in cycles independent of human
activities.
• At the current time, we are experiencing a slow global
warming, but it is not known to what extent this is part of a
natural cycle as distinct from human-induced (by increasing the
amount of carbon dioxide and other “greenhouse gases”, due to
combustion of fossil fuels and other human activities).
• There is concern that the increasing use of fossil fuels might
induce a “runaway greenhouse” effect, because heating of the
atmosphere could, by heating of the oceans and other water
bodies, result in increasing water vapor in the atmosphere (which
is also a “greenhouse gas”)!
• Global warming would also result in melting of the polar ice
caps, which would raise the water level of the oceans and cause
flooding of coastal areas of the continents.