Title: Continental Drift and Plate Tectonics
1Continental Drift and Plate Tectonics
2What is Plate Tectonics
- Early Ideas
- Alfred Wegener
- Continental Drift
- Earths lithosphere moves over time - Pangaea
(break up) - Theory of Plate Tectonics
3Wegeners Theory
4Evidence of Plate Movement
5Fossil Evidence
6Convection at a Ridge
7Sea-Floor Spreading
8Discovery of Sea-Floor Spreading
9Theory of Plate Tectonics
- The crust is divided into plates
- The plates move (a few cm/yr)
- Movement caused by mantle convection
- Different events occur at plate boundaries
10What is a Plate
- Large slab of rock/Lithosphere
- Floats on crust (Asthenosphere)
- Oceanic is dense basalt
- Continental is lighter granite
- Size and thickness vary
- Oceanic is thin (15 KM)
- Continental is thick (200 KM)
11The Earths Plate Boundaries
Plate Movement
12Ring of Fire
13Earthquakes
Volcanoes
14Mantle Convection
15What Drives It Convection
16Divergent Boundaries
- Plates move apart
- Ocean
- Sea floor spreading
- Land
- Rift Valleys
- Characteristic features
- Fracture zones
- Mid-ocean ridges/rift valleys
- Earthquakes and Volcanoes
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18The Plate Tectonics Model
19The Plate Tectonics Model
20Convergent Boundaries
- Plates move towards each other
- Subduction Boundary
- One plate moves underneath another
- Ocean/ocean - trenches form
- Ocean/Continent (subduction)
- Continent/Continent (Mountains)
21Convergent Examples
22Push and Pull
23Transform Boundaries
- Platespast each other
- Earthquake activity
- Faults
24Transform Plate Movement
25San Andreas Fault
262004 Asian Earthquake
- 9.0 magnitude
- Resulted in multiple tsunamis
- Up to 30 feet in height
- Traveling at speeds of 500 mph
- 700 miles of faultline slipped 50 feet vertically
- India plate pushed under the Burma plate (click
to view map of plate movement)
27Eyewitness Video
Click to view video of tsunami as it strikes
Patong Beach Thailand. This video takes a few
minutes to download 10MB (windows media player)
28Effects of 2004 Asian Earthquake
- Human loss
- Over 140000 lost their lives
- Hundreds of thousands more were injured
- Millions were left homeless
- Threat of disease for survivors
- Destruction of property
- Click for video (realplayer)
29Arial of Tsunami Floodplain
Indonesian Coastline after 2004 tsunami
30Asian Tsunami 2004
Click on image for original movie
31Causes of Plate Movement
- Mantle Convection
- Ridge Push
- Slab pull
32Plate Movement and Continental Growth
- Reconstructing the past
- Pangaea
- Craton
- Material sources of continental growth
- Igneous rocks
- River sediments
- Terrranes (crustal block or fragment)
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34Learn More
- Try it for yourself
- Take an online quiz
- Labeling Quiz - Divergence
- Labeling Quiz - Convergence
- Flash cards
- Matching
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36Present Day Atlantic
37How Plates Move
38Fit of Continents Across the Atlantic
39Atlantic 65 m.y. ago
40A Subduction Zone
41Why Mountains are High
42Where the Plates Meet
43Hot Spots
44Hot Spots Hawaii
45Pacific Hot Spot Tracks
462004 Asian Earthquake
- 9.0 magnitude
- Resulted in multiple tsunamis
- Up to 30 feet in height
- Traveling at speeds of 500 mph
- 700 miles of faultline slipped 50 feet vertically
- India plate pushed under the Burma plate (click
to view map of plate movement)
47Eyewitness Video
Click to view video of tsunami as it strikes
Patong Beach Thailand. This video takes a few
minutes to download 10MB (windows media player)
48Effects of 2004 Asian Earthquake
- Human loss
- Over 140000 lost their lives
- Hundreds of thousands more were injured
- Millions were left homeless
- Threat of disease for survivors
- Destruction of property
- Click for video (realplayer)
49Arial of Tsunami Floodplain
Indonesian Coastline after 2004 tsunami
50Asian Tsunami 2004
Click on image for original movie
