chapter 9: plate tectonics review
DESCRIPTION
Chapter 9: Plate Tectonics Review. Feb 11, 2013. What to study?. Layers of the Earth Convection Currents Continental Drift Sea-floor Spreading Theory of Plate Tectonics Plate Boundaries Crustal Features Shadow Zone http://txstar.cpo.com/ Username: mustang Password: science - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/1.jpg)
Chapter 9: Plate Tectonics Review
Feb 11, 2013
![Page 2: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/2.jpg)
What to study?• Layers of the Earth• Convection Currents• Continental Drift• Sea-floor Spreading• Theory of Plate Tectonics• Plate Boundaries• Crustal Features• Shadow Zone• http://txstar.cpo.com/
– Username: mustang– Password: science– Study Plate Tectonics 8.9A and 8.9B
![Page 4: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/4.jpg)
From the Earth’s Crust to the Inner Core:Depth IncreasesPressure IncreasesTemperature Increases
Layers of the Earth Temp.
(°C)Crust 0- 860 °C
Mantle 870°C
OuterCore
2200°C
InnerCore
5000°C
![Page 5: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/5.jpg)
Lithosphere
• This layer is broken down into several large tectonic plates
![Page 6: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/6.jpg)
Asthenosphere
• The asthenosphere is the semi-rigid part of the middle mantle that flows like hot asphalt under a heavy weight.
• The tectonic plates float on this semi-liquid layer.
![Page 7: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/7.jpg)
Lithosphere Vs. Asthenosphere
Lithosphere= rigidAsthenosphere= semi-soft
![Page 8: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/8.jpg)
Convection Currents in the Mantle
• According to scientists, convection currents is the driving force behind the movement of the Earth’s plates.
http://www.absorblearning.com/media/item.action?quick=12p#
![Page 9: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/9.jpg)
Convection
• Heated water is less dense therefore rises while Cooled water is more dense, which sinks.
• This is also true with air
![Page 10: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/10.jpg)
Alfred Wegener’s hypothesis on Continental Drift
• Evidence from Landform• Evidence from Fossils• Evidence from Climate
All the continents had once been joined in a single landmass, called Pangaea, and have since drifted apart.
![Page 11: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/11.jpg)
Evidence of Continental Drift A mountain range lines up between Argentina in South America and
Africa. Fossils of the reptiles Mesosaurus and Lystrosaurus have been found in
places now separated by oceans. Fossils of the fernlike plant, Glossopteris, have been found in rocks in
Africa, South America, Australia, India, & Antarctica. Deep scratches in rocks show that continental glaciers once covered South
Africa.
![Page 12: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/12.jpg)
Continental CoastlinesWhy don’t the continents look like they did millions of years ago?
• Coastlines change over time due to beach erosion.
![Page 13: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/13.jpg)
Pangaea
• A supercontinent, meaning “all lands”, that existed about 300 million years ago.
![Page 14: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/14.jpg)
Scientists Reject Wegener’s Hypothesis
• Wegener could not provide a satisfactory explanation for the force that pushes or pull the continents.
![Page 15: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/15.jpg)
Sea-Floor Spreading
Molten material rises from the mantle and erupts along the mid-ocean ridge
![Page 16: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/16.jpg)
Mid-Ocean Ridge
![Page 17: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/17.jpg)
Subduction• Process by which the ocean floor sinks
beneath a deep-ocean trench and back into the mantle.
![Page 18: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/18.jpg)
Plate Tectonics
• Geological theory that states that pieces of Earth's lithosphere are in constant, slow motion
![Page 19: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/19.jpg)
Earthquakes
• Occur usually when 2 plates slide past each other, however, can happen at all plate boundaries.
• Release of energy when the lithosphere suddenly breaks and slides
![Page 20: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/20.jpg)
Convergent Boundaries
• Two plates collide• Example: Himalayan Mountains• Folding mountains, volcanoes, and trenches
can form as a result of plates colliding.
![Page 21: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/21.jpg)
Divergent Boundaries
• Plate boundary where 2 plates move away from each other.
• Is the result of new ocean floor, such as the mid-ocean ridge and valley’s on land.
![Page 22: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/22.jpg)
Transform Boundaries
• Plate boundary where two plates slip past each other, moving in opposite directions.
• Earthquakes frequently occur along these boundaries.
![Page 23: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/23.jpg)
Cause of Deep Ocean Trenches
• When an ocean plate collides with a continental plate, the plate is subducted under the continent.
![Page 24: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/24.jpg)
Ring of Fire
Volcanoes form where tectonic plates meet other plates.
![Page 25: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/25.jpg)
Seismic Waves (PreAP)• Scientists use the properties of waves to study the
internal structure of Earth. Seismic waves are sound waves that may be generated by earthquakes.
• Primary waves, also known as P-waves, are longitudinal waves and can travel through both solids and liquids.
• Secondary waves, also called S-waves, are transverse waves that only travel through solids.
• As these waves pass through the interior of Earth, they change speed or may become refracted or reflected.
![Page 26: Chapter 9: Plate Tectonics Review](https://reader036.vdocuments.us/reader036/viewer/2022081512/56816232550346895dd26783/html5/thumbnails/26.jpg)
Shadow Zone• A wave-free shadow zone exists because the waves are
refracted from their original path as they pass through the boundary between the mantle and the core where they experience changes in density.
Earthquake Epicenter
P- and S- Waves P- and S- Waves
P-Waves only
shadow zoneshadow zone
103 º 103 º
143º 143º