Erosion and Deposition

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Erosion and Deposition

• Before we begin Write down the following
  questions. You will answer these as we go through
  the powerpoint.
• 1. What is erosion? What is deposition?
• 2. What are the four agents that cause erosion?
• 3. What is the most influential agent of erosion?
• 4. What different landforms can streams create?
• 5. What is created when the roof of a cave
  collapses?
• 6. How are sea caves, sea arches, and sea stacks
  created?
• 7. How does wind erode rocks?
• 8. Name three things that gravity can cause due
  to erosion.
• 9. How do glaciers cause erosion?

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Erosion and Deposition
Erosion- process that moves weathered
sediments from one place to another Deposition-
the dropping of sediments that have been
eroded Sediment- The tiny grains of broken down
rock Erosion and deposition are two parts of the
same process. Erosion only occurs when there
is enough energy to carry the sediments.
Deposition occurs when the energy decreases.
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There are four main forces that cause erosion and
deposition 1. Gravity 2. Running Water 3.
Glaciers 4. Wind
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Water

• The most influential force of erosion is water
  due to its ability to move materials from one
  location to another and its vast presence over
  earth.
• Examples include bodies of water such as rivers
  and streams.

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Water

• Rivers and streams in the landscape cause erosion
  and deposition and constantly shaping the land.
• Moving water works with gravity to affect the
  landforms that the water makes.
• Channel- the path that a stream follows due to
  the erosion from water on soil and rock. As the
  channel gets wider and deeper, canyons and
  valleys can form.

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Floodplains

• When a stream floods, a layer of sediment is
  deposited over the flooded land. Many layers of
  deposited sediment can form a flat area called a
  floodplain.

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Delta

• When a stream empties into a body of water, such
  as a lake of an ocean, its current slows and
  deposits its load. Streams often deposit their
  load in a fan shaped pattern called a Delta.

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Alluvial Fan

• Alluvial fan is a fan-shaped deposit that forms
  on dry land when a stream flows onto a flat land
  surface from mountains or hills.

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Groundwater

• Groundwater is the water located within the rocks
  below earths surface.
• Slightly acidic groundwater can cause erosion by
  dissolving rock leading to the formation of caves
• Sinkhole- occurs when the roof of a cave
  collapses, leaving a circular depression.

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Sinkhole Current Event Link

• http//www.cnn.com/2013/11/14/us/florida-sinkhole/

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What forces shape a shoreline?

• Waves play a major part in building up and
  breaking down a shoreline.
• The first parts of the shoreline that waves meet
  are the headlands. The waves slowing waves bend
  towards the headlands, which concentrates the
  waves energy. A huge amount of energy is released
  when waves crash into headlands, causing the land
  to erode.

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What coastal landforms are made by erosion?

• Sea cliff- a cliff that is formed when waves
  strike a cliffs base, wearing away the rock.

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Sea Caves, Arches, and Stacks

• As the rock making up sea cliffs erodes, it
  breaks and cracks. Waves can then cut deeply into
  the cracks and form large holes that continue to
  erode, which are known as sea caves.
• Sea arch- A sea cave that has eroded even
  further.
• Sea stacks- isolated rock that forms when the
  tops of sea arches collapse.

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Wind

• Wind can erode rocks over a long period of time.
• When wind blows sand and other particles against
  a surface, it can wear down the surface over
  time.
• The grinding and wearing down of rock surfaces
  over time is known as abrasion.

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Gravity

• Gravity works with other agents of erosion and
  deposition which can result in landslides,
  mudslides, and sinkholes.
• The force of gravity can move water and ice and
  make rock, soil, snow, or other material move
  downhill.

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Glacier

• A glacier is a large mass of moving ice that
  forms by the compacting of snow.
• As glaciers move due to gravity, they pick up
  materials that become embedded in the ice. As the
  glacier moves forward, the materials scratch and
  abrade the rock and soil underneath the glacier,
  causing more erosion
• Glaciers are also agents of deposition. When a
  glacier melts, it drops materials that it
  carried.
• A Glacial drift is the term for all of the
  materials carried and deposited by a glacier.
• Alpine glacier- A glacier that forms in a
  mountainous area

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Glaciers
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