Transcript unit 4 water cycle weathering

Part 1:Water Cycle and Ground
Water
Add the Yellow words to your note
packet.
A. Water Cycle
- condensation- water vapor (gas) turns to liquid
- deposition- 1. water vapor (gas) turns to solid
- sublimation- 2. when solid water turns into water vapor
-_________________solid or liquid water that falls to the
precipitation
Earth’s surface (one of four things an happen to it).
a. ________________water that is stored on the land
storage
surface as ice or snow.
b. ________________water that seeps into the earth
infiltration
and becomes subsurface water.
runoff
c. ________________water that flows on the surface
of the land.
d. evapotranspiration- evaporation of water from
large bodies of water and plants
The Water Cycle
Amount of plants
controls
transpiration
Evaporation
is controlled
by
temperature
A. Water Cycle
regolith- soil and rocks at the Earth surface above the bedrock.
Zone of saturation
________________________area where the pores between
solid particles are filled with water.
Zone of aeration
________________________area where the spaces are
partly filled with water.
Water table
________________________where the two zones meet.
- water under the water table is
called ground water.
Zones of Soil Water
B. Factors Affecting Infiltration
1. Slope of the land- steeper the slope (gradient) the
less the infiltration.
2. The degree of saturation of the regolith- the more saturated
the soil already is, the less the infiltration.
B. Factors Affecting Infiltration
3. The porosity of the regolith
porosity- is the percentage of open space
in a material compared to its total volume.
Generally, the greater the porosity the greater the
infiltration
factors affecting porosity
a. shaperound has greater porosity than angular
b. packing- loosely packed have greater porosity than
closely packed.
sorted has greater porosity than unsorted
c. sortingparticle size has no effect on porosity
B. Factors Affecting Infiltration
permeability
4. __________________the ability of a material to allow
fluids, such as water, to pass through it.
- permeability rate- the speed at which fluids will flow
through a material.
- a material can be porous but impermeable (not
permeable), if the spaces aren’t connected due to
tight packing or cemented particles
- If soil is loosely packed the larger the size of the
soil particles the faster the permeability rate.
B. Factors Affecting Infiltration
5. capillarity- attractive force between water and soil particles
that prevents some of the water from moving
downward.
- smaller particle size the greater the capillarity.
Capillary water
- ____________________water that is stored in some
of the small openings in the zone of aeration.
C. Factors Affecting Runoff and
Stream Discharge
Runoff occurs when
1. rate of precipitation exceeds the permeability rate
of the earth’s surface.
2. the regolith pore space is saturated
3. the slope of the surface is too great to allow
infiltration to occur.
C. Factors Affecting Runoff and
Stream Discharge
Stream discharge- volume of water flowing past a certain spot
in a stream in a specific amount of time.
- most runoff gets into streams and as runoff increases,
discharge increases
Water Pollution
Two main types: point source – pollution from a single point
of origin i.e. improper sewage systems, industrial waste.
Nonpoint source – pollution from widely spread areas i.e.
rainwater that carries pesticides and fertilizers, runoff from
roads and parking lots.
Weathering
- chemical and physical breakdown of rocks
on or at the Earth’s surface into smaller fragments.
- Climate
is the most important factor that
affects weathering.
Physical Weathering
Chemical Weathering
A. Physical Weathering
- occurs when rock is cracked, split, or broken into smaller
pieces called ________________.
sediments
- sediments are classified by size. (boulders, cobbles, pebbles,
sand, silt, clay, colloids, and dissolved particles)
1. __________________breakup of rocks by freezing
Frost Action
and thawing of water.
- water molecule expands by 20% as it freezes
Example of Frost Action
A. Physical Weathering
abrasion
2. __________________physical wearing down of
rocks as they rub or bounce against each other.
-dry windy areas, under glaciers, stream channels.
3. __________________peeling away of large sheets
exfoliation
of loosened material at the surface of a rock.
4. plant roots split the rocks.
Called plant action
Example of Exfoliation
Example of Plant Action
B. Chemical Weathering
- occurs when rock is broken down by chemical action
resulting in a change in the composition of the rock.
- oxygen, rainwater, carbon dioxide, and acids produced
by decaying plants and animals.
oxidation
1. _______________occurs when oxygen unites chemically
with minerals.
- when oxygen combines with iron you get rust.
Fe + O2  FeO2 Mineral - Hematite
2. _______________occurs when water unites chemically
hydration
with minerals.
- hornblende or feldspar, unite with water, they crumble
into small particles of clay.
Oxidation and Abrasion
B. Chemical Weathering
Carbonation
3. _______________-occurs
when carbon dioxide unites
chemically with minerals.
-when carbon dioxide is dissolved in water it forms
weak carbonic acid. This acid dissolves large masses of
limestone, creating caves, caverns, and other structures.
CO2 + H2O  H2CO3 Carbonic Acid
- sink holes- Saucer shaped holes on the surface
of the land are left when acid dissolves limestone
in ground. Area with these sink holes is
Karst topography
called____________________________.
- _________________grow from cave ceilings.
stalactites
stalagmites
- _________________grow up from floor.
Sink Hole Landscape
B. Chemical Weathering
Organic decay
4. ___________________occurs when acids, which are
formed when plants and animals decay, dissolve in
water. These acids dissolve rock.
C. Climate and Weathering
Physical- Moist climates with wide temperature
ranges
Chemical-
Warm, moist climates (tropical like)
Climate controls the type and amount of weathering
Climate and Weathering
List the type of weathering in the column that would allow it
occur in the greatest amount. Use under water and
temperature only once.
Water
Needs water
Frost Action
Temperature
Does not
Consistent
Variable
need water Temperature Temperature
Abrasion*
Plant Action
Frost Action
Exfoliation
Plant Action
Exfoliation
Oxidation
Hydration
Oxidation*
Hydration
Carbonation
*Could be both
Carbonation
Abrasion does not depend
on temperature.
D. Weathering Rate
-the smaller the particles (greater surface area), the greater the
weathering rate.
-hard rocks weather more slowly than soft rocks.
Metamorphic rocks weather the slowest, sedimentary
rocks weather the fastest.
- weathering occurs faster in humid climates than in dry ones.
Humid – round, smooth sediments
Arid – jagged, angular sediments
Climate and Landscape
Humid Climate
Arid Climate
II Soils
-part of the weathered regolith in which rooted plants will
grow.
- made of pieces of rocks , minerals , and organic matter
residual soil- soil formed by weathering of the bedrock found
beneath it
Soil minerals same as bedrock minerals.
transported soil- soil formed from rocks that were
moved to their present locations
Soil minerals (different from bedrock).
Basic Soil Make Up
minerals
air
water
organic matter
Soil Profile
-series of soil layers (more complex as soils mature)
-- soil horizon- layer of soil
A-horizon (topsoil)- contains organic matter
and the most weathered rock, plant and animal life
B-horizon (subsoil)- below A-horizon
- doesn’t contain much organic matter
- contains minerals that rainwater carried out of the
A-horizon.
C-horizon (bottom layer)- partly weathered bedrock
Soil Changes as it Matures
Weathering breaks up rock.
Plants and organisms die to
add organic matter.
Rainwater carries
minerals from A horizon
to B horizon.
Soil Profile Diagram
Humus (organic matter)
A Horizon - Zone of Leaching
B Horizon – Zone of
Accumulation
C Horizon – slightly
weathered bedrock (parent
material)
Soil Conservation
Crop rotation
1. _______________________by changing the crops from
year to year helps prevent depletion of nutrients.
Contour plowing
2. _______________________crops are planted in rows
parallel to the contours of the land. (helps prevent
erosion)
Strip cropping
3. _______________________low cover crops are planted
between strips of other crops. (helps prevent erosion)
Soil Conservation
Terracing
4. ___________________series of steps cut into a hill.
(helps prevent erosion)
Windbreaks
5. _______________________belts of trees along the edge
of farming areas. (helps prevent erosion by wind)
III Erosion
-the
transportation of loose sediments or rocks
- - Caused by gravity, running water, glaciers, wind,
and waves
-- the most common sediments are
Transported sediments
____________________________
(rock material that has
been transported from its place of origin to another location.)
Residual sediments
-The other sediments are ___________________________
which is weathered rock that has remained in its place of
origin.
A. Transported Material
- are unlike
the rocks on which they are deposited.
abrasion
- _____________grinding and hitting of one rock against
another.
- gravity, water, wind, and ice are the major forces, or agents,
affecting the transportation of weathered material.
1. Gravity
Mass Movement Animation
-the primary driving force behind erosion.
-pulls rocks down a slope (causes particles to be angular).
- gravity causes water to flow downhill.
- gravity causes glaciers to flow outward.
Slow – soil creep
Fast – landslide, mudslide
2. Running Water
Virtual River
- responsible for most erosion.
- causes particles to be rounded and smooth.
- carrying power- the ability of a stream to move particles
of different sizes.
- depends mainly on velocity
- stream velocity- depends on stream discharge and
gradient.
Volume of the water in a stream
- stream discharge- flowing past a specific point
Greater discharge equals faster velocity
- gradient- Steepness of the slope down which the stream
is flowing
Steeper gradient equals faster velocity
2. Running Water
- channel shape and velocity
- the velocity of a stream is generally greatest
just beneath the surface near the center of the channel
, where there is less friction with the banks of the river
and the atmosphere.
- water near the outside
of a curve has greater
velocity than water near the inside
of the curve.
- erosion takes place on the outside
of the curve
and deposition takes place on the inside
Stream Channel and Velocity
Cross section
Greatest velocity
Cross section
Arial/Map View of a Stream
Channel
Meandering Stream
Oxbow Lake
2. Running Water
velocity and sediment size
- the size of particles that can be carried by a stream
increases as the velocity of the stream increases.
Watch out
for this
scale!
2. Running Water
stream load
- material carried by a stream.
1. Dissolved particles in solution.
2. fine sediments of clay, silt, and colloids in
suspension
_________________.
3. larger sand and pebbles that are bounced ,
along the stream
pushed , or rolled
Called bed load
bed.
3. Wind
the greater the velocity of the wind, the larger
particles it can carry.
- causes particles to be frosted and angular
On Mars
On Earth
the
4. Ice/Glaciers
widespread over Northern North America.
- most of New York State shows evidence of glacial
erosion.
- carries the largest things, boulders
- cause particles to be partly rounded , with some
scratches
Glacial Erosion Animation
Glacial Features
Wave Action
-Erosion and deposition cause changes in
shoreline features, including beaches,
sandbars, , and barrier islands. Wave action
rounds sediments as a result of abrasion.
-Waves approaching a shoreline move sand
parallel to the shore within the zone of
breaking waves.
Longshore Drift
Longshore drift is the movement of sediment
parallel to the shore as waves strike the
shoreline at an angle.
Jetties- rock walls designed to protect the
entrance of a harbor from sediment
deposition and storm waves.
Groins- walls built to protect beaches that are
losing sand from longshore drifting.
Jetty
BreakwaterSand piles up against one jetty while the beach beside
the other erodes back into the shore.
Groin
Groins are built perpendicular to the shore to trap moving
sand and widen a beach.
Animation
Beach Erosion
Beautiful vacation home, or costly death trap?