Chapter 9: The Hydrosphere

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Chapter 9 The Hydrosphere
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Objectives

• Describe and illustrate the hydrologic cycle
• Learn about oceans
• Describe surface and underground water.
• Study the Ogallala aquifer in the Great Plains
  region

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Outline of the Session

• The Hydrologic Cycle
• The Oceans
• Permanent Ice
• Surface Waters
• Underground Water

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1. The Hydrologic Cycle
A ceaseless interchange of moisture in terms of
its geographical location and its physical state.
These can be conceived as series of storage areas
interconnected by various transfer
processes Surface to Air movement of water Air
to Surface movement of water Movement on and
Beneath Earths Surface Residence times
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The Hydrologic Cycle

• Moisture inventory
• Oceans 97.2
• Glaciers 2.0
• Groundwater 0.5
• Freshwater lakes 0.1
• Saline lakes 0.1
• Soil water 0.04
• Stream, atmospheric, and biological water 0.01

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The Hydrologic Cycle
1 What is in storage? 99 2.  What available
for movement in hydrologic cycle 1
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The Hydrologic Cycle
Movement on, over and Beneath Earths
Surface Condensation The process of water
changing from vapor state to liquid. Cool air
condenses into clouds Precipitation falls on
land and collects on the surface. It is water
being released from clouds as rain, sleet, snow,
or hail. Runoff or Overland flow that portion
of Earths circulating moisture that moves in the
liquid state from land to sea Infiltration
downward movement into the ground.
Evapotranspiration Consumptive use evaporating
from the ground and transpiration by plants.
water vapor re-enters the atmosphere.
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The Hydrologic Cycle
1. What is in storage? 2.  What available
for movement in hydrologic cycle
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The Hydrologic Cycle
Air-to-Surface Water Movement precipitation 77
falls on oceans      23 falls on land P
Evapo-transpiration streamflow change in
storage Balances in time not on space  Why are
oceans not dried up? Precip gt Evapo-transpiration
Precipitation over the ocean
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The Hydrologic Cycle
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The Hydrologic Cycle
Residence Times Glacial ice thousands of
years Ground Water 100-1000s years Atmosphere
a few days Precipitation
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2. The Oceans
How many? Characteristics Movement of ocean
waters Focus Tides
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The Oceans

• Pacific How Extensive? How Big?
• Twice as big as any other water body
• Tropical ? 1/3 the area of the earth. 46 of
  all water present
• 2. Atlantic 23
• 3. Indian 20
• 4. Arctic 4
• Which one is the shallowest and smallest
• Sea denote smaller body of water

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Red Sea  L.   Pacific Ocean  A.   Hudson
Bay  B.   Sea of Okhotsk  K.   Indian Ocean 
F.   Black Sea  H.   Sea of Japan  D.  
Yellow Sea  M.   South China Sea  E.   Gulf
of Mexico  G.   Atlantic Ocean  N.   Baltic
Sea  I.   Caribbean Sea  J.   Mediterranean
Sea  C.  
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The Oceans
Movement of ocean waters
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The Oceans
Characteristics Chemical Composition Salinity
concentration of dissolved salts      mostly
sodium chloride 3.5 Where will it be lowest?
/ Highest?  Temperature Depends on lat (80o F in
tropics  28o F in poles Western sides warmer
than eastern margins Density Depends on
temperature, salinity, and depth High density
when low temperatures, high salinity, deep
water Surface layers of seawater contract and
sink in cold regions deeper water rises to
surface in warm areas The Persian gulf may soon
run out of fresh water http//water1.geol.upenn.ed
u
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Movement of ocean waters
1. TidesRhythmic fluctuations or bulges in the
sea level. How are they caused? 2. Currents Are
a continuous flow of water along a definite path
based on energy gradient. Role of wind flow,
Temperature and salinity contrasts, size and
shape of ocean, configuration and depth of sea 3.
Waves Propagating disturbance in the medium due
to transfer of energy without net movement of the
mass. How about Tsunami ?How does the Coriolis
effect ocean waters?
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Focus Tides
Role of gravity Depends on Distance and Mass 44
daily tide cause by sun, 56 by moon Ocean
bulges, 2 high tides and 2 low tides every 25
hours Flood tide Movement of water toward the
coast High tide Maximum water level Ebb
tide Movement of water away from the
coast Low tide Minimum water level Tidal
range difference between high and low
tide Spring tides highest tide, 2x/month near
full and new moon Neap tides lower than normal
tidal range Sun and Moon at right angles Perigee
when moon at nearest to Earth Apogee when
farthest point from Earth Tidal bore A wall of
seawater (several inches to several feet) rushing
up a river  Tidal range Normal 5-10 feet,
Largest 50 feet
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3. Permanent Ice
2nd largest storage reservoir.     3 types 1.
Ice on land10 of Earths land, alpine
glaciers, ice sheets, ice caps 2. Ice floating
on ocean a.      fresh water salt not taken up
when water freezes Largest ice pack The Arctic
Ocean 3.     Permafrost permanently frozen
subsoil Where do you expect permafrost? Why and
when?
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3. Permanent Ice
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4. Surface Waters Lakes
Surface Waters Lakes Lakes Surrounded by
land 40 lake water is saline      Caspian
Sea 75 of non-oceanic saline Saline When no
outlet or drainage Distribution Glaciated
areas Rift valleys Africa Sinkholes in
limestone areas Worlds largest and deepest
freshwater lake Baykal, Siberia What do you
think the Human impact on lakes are likely to be?
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4. Surface Waters Lakes
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Surface Waters Swamps
B Swamps and Marshes Flat areas submerged in
water at least part of the time but shallow
enough to permit the growth of water tolerant
plants Swamp trees dominate Marsh grasses and
rushes dominate Where do you find them? Coastal
areas, river valleys, or recently glaciated
areas Why do you think are wet lands vanishing?
What are their functions?
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Surface Waters Rivers and Streams
Dynamic part of the hydrologic cycle Drainage
basin all the land area drained by a river and
its tributaries 2 dozen great rivers produce ½
worlds total stream discharge Amazon River 20
(3x all US rivers) Mississippi River largest in
N America Drainage basin covers 40 land area of
48 states Accounts for 1/3 discharge of all US
rivers
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Rivers and Streams
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5. Underground Water
Ground water flow function of Porosity Permeabili
ty Groundwater flow rate permeability X
hydraulic gradient Interstices openings Clay
high porosity but low permeability  
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Underground Water
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Underground Water
Aquifer a permeable rock layer stores, transmits
and supplies water Aquiclude an impermeable
rock layer that is so dense as to exclude
water Hydrologic zones zone of aeration zone
of saturation zone of confined water waterless
zone
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Underground Water
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Underground Water
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Underground Water
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Underground Water
Hydrologic zones zone of aeration zone of
saturation zone of confined water waterless zone
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Underground Water
Hydrologic zones Zone of aeration Top most
zone below the surface, Mixture of solids,
water and air Pores are partly filled with air
and partly with water Water may be held in
suction because of capillary action
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Underground Water
Hydrologic zones Zone of Saturation 1.      all
pore spaces are fully saturated with
water 2.      water table top of the saturated
zone Follows the general configuration of the
land Lakes, swamps, marshes, or permanent
streams form where water table intersects the
surface 3.      Perched water table localized
zone of saturation that develops above an
aquiclude 4.      Cone of depression water table
drop surrounding a well
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Underground Water
Hydrologic zones Zone of Confined Water 1.     
not in all parts of the world 2.      separated
from zone of saturation by impermeable
rock 3.      artesian well free flowing well
created when pressure in confined aquifer is
sufficient to force the water to the
surface.  Piezometric surface the elevation to
which water will rise under natural confining
pressure.  Sub-arteisan well Free flow when a
well is drilled.
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Underground Water
Artesian well free flowing well created when
pressure in confined aquifer is sufficient to
force the water to the surface. Piezometric
surface the elevation to which water will rise
under natural confining pressure.  Sub-artesian
well Free flow when a well is drilled.
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Underground Water
Hydrologic zones Waterless Zone 1.     
overlying pressure increases rock density so
there are no pores 2.      begins several miles
below land surface
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People and the Environment
Ogallala aquifer, largest US aquifer, 225,000
mi2 in the Great Plains Geology Limey and sandy
layers Few inches (TX) to 1,000 feet (NE) 30,000
years of accumulation Tapping early 1930s, rapid
spread in high-yield farming 170,000
wells Farmers shifting to crops that require less
water Water and energy conserving
measures Estimate in next 4 decades 5 million
acres now irrigated will revert to dry-land
production Geographic differences Nebraska
Sandhills Deepest aquifer, minimal water use,
relatively rapid recharge rate, Southwestern
Kansas withdrawal 22x recharge estimate water
will run out 2019,  
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People and the Environment
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People and the Environment
problem groundwater does not respect of property
boundaries     "San Antonio Water Rights" -
"Talk of the Nation - Science Friday" segment
from Dec. 4, 1998 discusses the tension between
urban and rural demands on groundwater pumped
from the Edwards Aquifer in south Texas.
(RealAudio)  
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Further readings

• Test your knowledge at http//wps.prenhall.com/es
  m_mcknight_physgeo_8/0,9340,1445231-,00.html  You
  find answers to thinking spatially also
• http//wps.prenhall.com/esm_christopherson_element
  algeo_4/0,7618,683781-,00.html

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Some questions
1. What are unique Properties of water? What
happens when there is change of state? 2. Compare
and contrast the effect of oceans in the Northern
and Southern Hemisphere 4. Prepare a sketch of
the natural and Human impacted hydrologic cycle?
How will pollution impact water resources
locally? What will be its impact on the
ecosystem? 5. How are tides formed. What are the
differences between tides, currents, and
waves? 6. Show different zones of underground
water 7. What lessons did you learn from the
study of the Ogallala aquifer?