Weathering and Erosion

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Transcript Weathering and Erosion

Weathering and
Weathering and Erosion
Weathering- Disintegration and decomposition of rock at or near the earth’s
Erosion- Incorporation and transportation of material by a mobile agent,
usually water, wind or ice.
Mass wasting (or the transfer of rock material down slope under the
influence of gravity) is one of the biggest factors in the cause of erosion.
Mechanical Weathering
Frost wedging- Freezing and thawing
of water causes weathering Because
water expands about 9 percent when
frozen. water works its way into cracks
of a rock, and then freezes causing the
expand water to push out of the rock.
Biological Activity- weathering is
also caused by activities of
organisms like, plants,
burrowing animals, and human
activity, even decaying
organisms produce acids that
contribute to weathering.
Thermal Expansion- Heating a rock
causes it to expand while cooling
causes it to contract. This process of
expanding and contracting from
the daily cycle of temperature is
called thermal expansion.
Chemical weathering
Involves complex processes that alter
the internal structures of minerals by
removing and/ or adding elements.
Water in the most important part of chemical
weathering. Alone pure water in nonreactive but
small amounts of dissolved material is all that is
needed for chemical weathering to occur.
Silicate minerals- The earths crust is mostly made
up of silicate minerals. When chemical weathered
silicate minerals yield sodium calcium potassium
and magnesium ions. These form soluble
products that may be removed by groundwater.
Carbon dioxide- When
carbon dioxide dissolves
in water it forms carbonic
acid. Rain dissolves some
carbon dioxide as it falls
through the atmosphere
and additional amounts
are dissolved from
decaying organic matter
as water percolates
through the soil.
What is Erosion and Deposition
What is erosion and Deposition?
Erosion Is the removal of loosened rock
pieces from a higher elevation to a lower
point with the action of natural agents.
Deposition is when the process of erosion
ends and transported particles settle on the
How dose gravity help erosion?
The energy of erosion comes from several
sources. Gravity acts to vertically move
materials of higher relief to lower elevations
to produce an equilibrium. It also acts on the
mediums of erosion to cause them to flow to
base level.
What is the difference between
erosion and deposition?
Erosion is when the water is eroding away the
bank causing it to get wider and wider over the
Deposition is the build up of sediments of
organically derived matter or chemical
Earth Subsystems
Everything in Earth’s system
can be placed into one of four
major subsystems: Land, Water,
Living things, or air. These four
subsystems are called
Specifically they are
•*Lithosphere- Land( Test question)
•Hydrosphere- Water
•Biosphere -Living things
Lithosphere contains all of the cold, hard solid land of the
planet’s crust (surface), the semisolid land underneath the
crust, and the liquid land near the center of the planet. The
surface of the lithosphere is very uneven. There are high
mountain ranges like the Rockies and Andes, huge plains or
flat areas like those in Texas, Iowa, and Brazil, and deep
valleys along the ocean floor.
Hydrosphere contains all the solid, liquid, and gaseous water
of the planet. It ranges from 10 to 20 kilometers in thickness.
The hydrosphere extends from Earth’s surface downward
several kilometers into the lithosphere and upward about 12
kilometers into the atmosphere. A small portion of the water
in the hydrosphere is fresh (non-salty) This water flows as
precipitation from the atmosphere down to Earth’s surface, as
rivers and strams along Earth’s surface, and as ground water
beneath Earth’s surface. Most of Earth’s fresh water is frozen.
97% of Eath’s water is salty. The salty water collects in deep
valleys along Earth’s surface.
Biosphere contains all the planet’s living things. This sphere
includes all of the microorganisms, plants, and animals of Earth.
Within the biosphere, living things form ecological communities
based on the physical surroundings of an area. These communities
are call biomes. Deserts, grasslands, and tropical rainforests are
three of the many types of biomes that exist within the biosphere.
Atmosphere contains all the air in the Earth’s systems. The upper
portion of the atmosphere protects the organisms of the biosphere
from the sun’s ultraviolet radiation. It also absorbs and emits heat.
When air temperature in the lower portion of this sphere changes,
weather occurs. As air in the lower atmosphere is heated or cooled, it
moves around the planet. The result can be as simple as a breeze or as
complex as a tornado.
*There are minerals found in water
like iron, sulfate, sodium, chloride
and fluoride. Also there are
minerals found in rocks. A mineral
can be any substance found in the
earth. For example aluminum is
the third most abundant mineral in
Earth’s crust.
Affect of surface and ground water
How our use and gathering of
energy, minerals, and rock resources
from the earth affect earth.
Ways resources are gathered.
• Fracking (Fracturing or Hydrofracing)
• Mining
The Affects of Fracking,
How does it Work?
How Does Fracking Work?
First, a hole is drilled into reservoir shale
rock formations. Next, a mixture of water
and chemicals is injected at a very high
pressure, and this causes gas to flow out
for collection or leaching
There are several chemicals used in
Super important
Land dregging: involves miners using a
generator to dig a large hole in the ground.
They use a high pressure hose to expose
the gold-bearing layer of sand and clay.
The gold bearing slurry is pumped into a
sluice box, which collects gold particles,
while mine tailings flow into either an
abandoned mining pit or adjacent forest.
When the mining pits fill with water from
the tailings, they become stagnant water
pools. These pools create a breeding
ground for mosquitoes and other waterborn insects. Malaria and other water-born
diseases increase significantly whenever
open pools of water are nearby. None of
these of these practices do anything to help
the environment or recharge it