Constructive and Destructive Forces

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Constructive and Destructive Forces
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Layers of the Earth
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Constructive ForcesIdentify surface features
caused by destructive forces.

• Construct means to build up.
• Forces that build up features on the surface of
  the Earth.
• Sediment (Deltas, sand dunes, etc.)
• Volcanoes (makes Islands)
• Tectonic Plates (Mountains)
• Crust deformation (Folding or Faulting)

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Sediment

• The process of sediment being carried causes new
  landforms.
• Wind sand transported by the wind creates sand
  dunes.
• Water bits of soil and rock can be carried
  downstream and deposited causing deltas.
• Ice glaciers pick up and move rock and other
  materials, depositing it elsewhere.

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Wind DepositionSand Dune Cumberland Island, GA
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Water Deposition Sediment is carried by river
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Glacial Deposition
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Volcano

• http//app.discoveryeducation.com/search?Nttvolca
  noerupt
• United Streaming-Fire Down Below

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Volcanoes

• A volcano is an opening in the Earth's surface or
  crust, which allows hot, molten rock, ash and
  gases to escape from deep below the surface.
• Volcanic activity involving the extrusion of rock
  tends to form mountains or features like
  mountains over a period of time.
• Magma (inside)
• Lava (outside)

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Volcanoes

• There are two main types of volcanoes shield and
  composite.
• Shield volcanoes are usually found in the middle
  of tectonic plates. Islands like Hawaii are good
  examples of this type of volcano. These are
  making new islands every yeartakes a long time.
  (Hawaiian Islands)
• There's a hole in the middle of the plate and
  magma moves out and piles on top of itself,
  slowly building a mountain of rock. (Katmai)

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Volcanoes

• 1. Magma reservoir2. Country rock3. Conduit
  (pipe)4. Base5. Sill6. Branch pipe7. Layers
  of ash emitted by the volcano8. Flank9. Layers
  of lava emitted by the volcano10. Throat11.
  Parasitic cone12. Lava flow13. Vent14.
  Crater15. Ash cloud

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HOT SPOT

• http//app.discoveryeducation.com/search?Ntthotsp
  ot
• United Streaming-Hot Spot

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Tectonic Plates

• Mountains can be formed because of moving
  tectonic plates.

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Tectonic Plates
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Faults

• Faults are cracks in the Earths crust.
• The surface of the Earth is made up of tectonic
  plates that are floating on magma (molten rock).
• It is along these fault lines that earthquakes
  and volcanoes occur.

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Destructive ForcesIdentify examples of surface
features caused by destructive processes.

• Destruct means to destroy.
• Forces that destroy features on the Earths
  surface.
• Erosion (water - rivers and oceans, wind)
• Weathering (chemical or mechanical)
• Impact of organisms
• Earthquake

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Earthquakes

• An earthquake is a phenomenon that results from
  the sudden release of stored energy in the
  Earths crust.
• It is caused by a strain on the fault lines of
  the Earths crust. When the energy of the strain
  is released, similar to a rubber band snapping,
  the earthquake occurs.
• At the Earth's surface, earthquakes cause a
  shaking or displacement of the ground and
  sometimes cause the ground to break apart and
  change shape. Earthquake Animation!

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Earthquake
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Weathering and Erosion

• Weathering is the breakdown of the continents and
  the land around you. The breaking down of these
  rocks and land due to forces such as wind and
  water is weathering. When it rains, rocks are
  washed down a mountain or down a stream. Soils
  are washed away. The ocean beats against a cliff
  and breaks it apart. If it is moved elsewhere it
  is called erosion.

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Mechanical Weathering

• Mechanical weathering is the process of breaking
  big rocks into little ones. This process usually
  happens near the surface of the planet.
  Temperature also affects the land. The cool
  nights and hot days always cause things to expand
  and contract. That movement can cause rocks to
  crack and break apart. Roots and plants also push
  into the rocks and break them apart. They act
  like wedges and push the rocks apart. Little
  animals also help by burrowing and digging
  through the ground.

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Chemical Weathering

• Chemical weathering includes the effect of
  weathering on molecules and atoms. As with all
  chemistry, the greater the surface area of an
  object, the more chemical reactions can take
  place. For these chemical reactions to happen in
  nature, moisture, and heat must be present.

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Biological Weathering(Impact of Organisms)

• Biological weathering would include the effect of
  animals and plants on the landscape. This is more
  than roots digging in and wedging rocks.
  Biological weathering is the actual molecular
  breakdown of minerals.

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Earthquakes

• More than buildings collapse when an earthquake
  hits. The land itself is totally changed. You can
  see scars across the landscape. Those scars
  appear when one block of land has moved compared
  to another. Roads often change their placement.
  They either become uneven or just crack. Streams
  can also change course. Sometimes rocks can fall
  and block the stream. Other times, the land is
  even lowered in certain areas. When it's lower,
  it's easier for the water to flow in the new
  direction .

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Earthquakes

• San Andreas Fault line is 810 miles and runs
  along California. It separates the tectonic
  boundary of the Pacific and North America
  boundary.

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Technology andHuman Interventions

• Humans try to CONTROL these forces.
• seismological studies
• flood control (dams, levees, storm drain
  management, etc.)
• beach reclamation (Georgia coastal islands)

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Seismic Waves

• Scientists study earthquakes so that they can
  understand how they work and so that they can try
  to predict future quakes.
• Earthquakes are recorded by instruments called
  seismographs.
• A short wiggly line means a small earthquake and
  a large one means a large earthquake.

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Seismic Waves

• These are waves of energy that travel through
  Earths layers studied by geologist.
• Primary (P waves) travel fast
• Secondary waves (S waves) travel through solids

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Flood Control

• The U.S. Army Corps of Engineers began
  constructing dams in Georgia for navigation and
  flood control in the 1940s and 1950s under the
  Flood Control Act of 1944 and the Watershed
  Protection and Flood Prevention Act of 1954.

Lake Allatoona was created in 1950 by the U.S.
Army Corps of Engineers for flood control. At
more than 12,000 acres, Allatoona is one of the
larger lakes in the state.
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Flood Control Methods

• Dams control the water flow in a stream or river.
• A levee is an embankment designed to prevent the
  flooding of a river.
• Storm drains are for carrying off rainfall
  drained from paved surfaces, roofs, etc.

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Beach Reclamation

• Weather, waves and wind cause the coastline to
  wash away.
• Keeping sand dunes intact helps to keep the
  beaches from eroding.

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Stone Mountainformed by plate tectonics
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Emerson fault
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Gorge
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Providence Canyon, GA
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Appalachian Mountains
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Sand Mountain
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Lime sinks-chemical dissolution of rocks
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Pine MountainChain Rock and KY first state park
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Cumberland FallsOnly Falls with Moonbow
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Beaches
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Brasstown Baldhighest natural point in GA
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Brevard Fault Zone
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Cumberland Plateau
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Lookout Mountainlast battle of Cherokees
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Blue Ridge Mountains
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Mississippi Riverlargest drain in USA