Lithospheric Movements

1
Lithospheric Movements
2
Tectonic Plates

• The pieces that the lithosphere is divided into.
• Drift on the asthenoshpere like chunks of ice on
  a pond.

3
Pangea

• Alfred Wegener
• 1915
• Theory of continental drift

4
(No Transcript)
5
Major Tectonic Plates

• Pacific
• North American
• South American
• African
• Eurasian
• Antarctic
• Indian
• Cocos
• Nazca
• Australian
• SEE TEXT, PAGE 62. BE ABLE TO LABEL THEM ON
  MAP!!!!!!!

6
Plate Boundaries

• Where most geologic activity takes place.
• They may separate, collide, or slip past one
  another
• Forms mountains
• earthquakes
• volcanoes

7
Himalayan Mountains

• Began to form when the tectonic plates containing
  Asia collided with the plate containing India 50
  million years ago.

8
Earthquakes

• Fault break in the Earths crust along which
  blocks of the crust slide against each other.
• When rocks suddenly break along a fault,
  vibrations are set off an earthquake occurs.
• Can be so small we dont feel them or enormous
  and cause wide spread damage.

9
Magnitude

• The measure of energy released by an earthquake.
• Smallest able to feel is 2.0, largest ever
  recorded is 9.5.

10
Where do they occur?

• Near tectonic plate boundaries
• San Andreas Fault line where parts of the North
  American Plate and Pacific Plate slip against
  each other.

11
Hazards

• Cannot predict them
• Can predict where they are likely to occur.

12
Volcanoes

• Mountain built from magma, or melted rock, that
  rises from the Earths interior to the surface.
• Located near tectonic plates are colliding or
  separating.
• Occur in land or sea if they break the surface
  of the sea, islands form.

13
Local Effects

• Clouds of hot ash, dust and gases can flow at
  speed of 200 km/hr and sear everything in path.
• Mudflow ash mixed with water.

14
Tsunamis

• Caused by rippling effect of underwater
  earthquakes, volcano eruptions, and landslides.
• Most occur around the pacific rim.

15
Global Effects

• Change climate for several years.
• Reduce the amount of sunlight, leading to a drop
  in global temperature.

16
Erosion

• The removal and transport of surface materials.
• Wears down rocks and makes them smoother.

17
Water Erosion

• Erosion by rivers and oceans.
• Erodes coastline
• Cause deep gorges.

18
Wind Erosion

• Plants hold soil in place in areas without
  plants, wind blows soil away quickly.
• Soft rocks erode faster