Ch. 23.1 Water

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Transcript Ch. 23.1 Water

Ch 23.1 Water & the Water Cycle
EARTH IS UNIQUE – ITS TEMPERATURES & PRESSURES ALLOW
FOR WATER TO EXIST IN ALL THREE STATES: SOLIDS, LIQUID,
AND GAS
WATER MOVES
THROUGH EARTH’S
ATMOSPHERE,
BODIES OF WATER,
AND LAND IN THE
WATER CYCLE.
.
TRANSPIRATION
Most of our drinking
water comes from
GROUNDWATER
(wells) and Surface
Water Reservoirs
(Lakes)
Video: http://www.cbsnews.com/stories/2010/01/08/eveningnews/main6073416.shtm
Video: http://www.msnbc.msn.com/id/21494919/ns/us_news-environment/t/crisisfeared-us-water-supplies-dry/
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Watersheds and Water Quality
Watershed: an area of land (and all of the streams,
lakes, etc on it) that drain into a particular river
system.
Watersheds are divided by mountains or ridges.
Watersheds and Water Quality
What degrades water quality in a watershed?
1. IMPERVIOUS SURFACES impact WATER
QUALITY
Surfaces like concrete or road that prevent water
from soaking into the ground (infiltrating).
As water moves through layers of rock, soil, and
leaves it is purified. More impervious surface 
less filtering of groundwater  poor water quality
Watersheds and Water Quality
2. IMPERVIOUS SURFACES impact
FLOODING
Surfaces like concrete or road that prevent
water from soaking into the ground
(infiltrating).
More impervious surface  less ground
water more run off going into streams 
flooding  more erosion
Watersheds and Water Quality
3. Point & Non-Point Pollution
Point Pollution: Pollution (chemicals, fertilizers,
bacteria, etc) from a SPECIFIC SOURCE/Location.
Examples:
• Mercury from an oil refinery
• Hexoflourine from a power plant
Non-Point Pollution: Cannot pin-point source;
Mutliple sources
Examples:
• Motor oil from road surfaces
• Pesticides/fertilizers from lawns, farms, or golf courses
• Fecal bacteria from farm animals
• Pharmacueticals flushed into waste water.
Watersheds and Water Quality
3. Point & Non-Point Pollution
Point & Non-point pollution enter water supply
by:
1. Carried by RUN-OFF that joins streams/rivers. (Pesticides,
Fertilizers)
2. INFILTRATES GROUND WATER.
Ground Water Terms (MCP)
AQUIFER = A large porous rock layer
that serves as a ground water source .
People use aquifers for drinking water
and agriculture (watering crops).
SPRING = A place where groundwater is
bouncing back to the surface.
Ground Water Concepts and Terms
Permeable Rock (Porous) = Limestone or Sandstone
- Allows water to flow through and stores water like a sponge
-Make up AQUIFERS (Large underground water storage that people use
for agriculture or personal wells)
Impermeable Rock = Slate or Granite
-Does not allow water to easily pass through
- Underlies permeable layers to make SPRINGS (where water bounces
back to the surface from the ground).
Ground Water Concepts and Terms
Unsaturated Zone= Layers of rock where there is room for
more water. There are still air spaces.
Saturated Zone= Layers of rock that are completely filled with
water. No air spaces.
Water Table = Top of the saturated zone; Rises after rain/
Drops during drought.
Ch 23.2 Weathering & Erosion
Weathering
• Process of chemically changing
or physically breaking down rock.
• Water and wind weather rock.
• Weathering happens on the
surface.
Erosion
Erosion = process that wears down and
carries away rock and soil fr. one place to
another
Agents of Erosion (What’s doing the
erosion?):
• Water – streams, rivers, oceans, glaciers
• Wind
• Gravity
End product of erosion = SOIL or SEDIMENT
TYPES OF Weathering
• Mechanical: physically break down rocks
into smaller fragments.
A. Frost wedging
B. Abrasion
C. Plant roots
• Chemical: Chemical reactions dissolve
minerals in rock
Acid rain
Examples or Mechanical Weathering
Expanding ice
and expands
Plant roots: Physically
break apart rock layers
Abrasion – water / wind carries
sand & rocks over surface &
smoothes it (sand blasting)
Hoodoos were created by frost wedging over a long period of time
Examples of Chemical Weathering
Red rock layers formed
by iron reacting w/
oxygen
Iron reacts w/ oxygen to
make blue soil.
Caves form when
limestone is dissolved
by acidic water
1. ACIDIC RAIN WATER will dissolve calcium
containing rocks (limestone, & marble). This is how
caves are made.
2. Oxidation (chemical reactions w/ O2) of Iron
containing rocks (Makes rust)
Weathering & Climate
Chemical Weathering & Climate
• Carbonic acid weathers rock and particles usually
end up on the bottom of the ocean floor..
• Carbonic acid forms when CO2 is dissolved in
water. This CO2 comes from the ATMOSPHERE.
• More chemical weathering = More CO2 removed fr.
Atmosphere.
• When “NEW” land is exposed to Earth’s surface,
weathering rates increase; temps. Decrease.
•
Mt. Building exposes new land.
Rates of Weathering depend on…
1. Temperature – Warmer temps. Increase
chem. Weathering / Alternating freezing
& warm temps. increase mech.
Weathering.
2. Availability of Water – More water, more
weathering
3. Type of Rock – Calcium containing rocks
(limestone, calcite, marble) are prone to
chemical weathering
Mass Movements= Erosion w/ help
of gravity. Once weathering has
broken rock up, gravity can move
rocks down slopes! (H2O usu. helps)
• Land slides – rapid, large amounts of
rock & soil
• Mudflows – rapid, large amounts of soil,
sediments & water
• Creep – gradual, soil moves down slope
(alt. freezing & cold temps)
• Slump – rapid, small amount of hillside
move down a “step” (Wet soil)
Types of Mass Movement (aka, mass wasting)
More rain means greater chance of mass movement
Creep
Slope
Landslide