y8 wk33 plate_tectonics_ppp
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Today: 1. Review notes for 3 min.2. Quiz for 4 min. m.socrative.com /52593/Real Name3. Introduce Plate Tectonics review the power point presentation at home (on Edmodo)! There will be a quiz next week
Homework: Hand in Answers to Question #2a.b.cTell Ms. Melanie your project group members.
Lab work: 1. Build 12 sugar cube houses. Stick them together with
Peanut Butter, Nutella, or margarine. Build each one on a piece of WAX paper.
2. Create Clay (Play Do) Soil Tray.
Warm Up Quiz: 4 minutes1. What is your name? __________
2. Which layer of the Earth is the densest?3. What are two differences between
Compositional Layers and Physical Layers?4. Earth’s Crust layer is also called the
___________.5. Which layer does the crust (tectonic plates)
move on?
Please sign your name and hand in
Or Complete on your cell phone!
Plate TectonicsPg. 202 – 213 in
Dynamic Earth textbook
Can you name all continents? What are they? With a partner, try to list as
many as you can.
Continents
Continents – Correct your work
Like continents, the Earth’s Crust is also divided into Continental plates.
How many continental plates are there?* main ones _______15
In1800, Alfred Wegener thought about this idea
Continents were once 1 land form (Pangaea)
They moved apart over time!
Evidence to support his hypothesis◦ Fossils found across the ocean on another
continent◦ Location of mountain ranges and rock formations
across the ocean, rocks are the same age◦ Tropical fossilized plants found in Arctic zones.
Continental Drift (<- Video)
Single landmass
Thought to exist 245 million years ago
Began to drift apart
Himalayas formed from Indian plate colliding with Eurasian plate.
Pangaea (< click for video)
Pangaea
The plates movedue to convectioncurrents in themantle.
Movement over time
Lava (magma) rises through the cracks in the oceanic crust.
It cools and forms new crust (lithosphere).
Mostly occurs in the sea.
Evidence:-Rock samples are young (not old)
- sea floor is not smooth, but rough with large trenches
Sea Floor Spreading
Sea Floor Spreading –> creates mid ocean ridges (new crust!)
WHY ISN’T EARTH GETTING BIGGER?
If new crust is being made…
Mid Ocean Ridge
Ocean Trenches: deep canyons in ocean floor
Older crust is sinking (subducting) into the asthenosphere at the same rate new crust is forming.
Ocean Trenches: Why isn’t Earth getting bigger?
Describes large scale movement of Earth’s lithosphere (by Convection in the Mantle)
Explains volcanoes, mountains, and earthquakes
Tectonic Plate: lithosphere is divided into rock pieces
Plates move on asthenosphere in different directions and speeds.
Theory of Plate Tectonics
Tectonic Plates:
Click above fora short video!
Most crustal changes occur at plate boundaries
3 main types: *Divergent (Drift Apart) *Convergent (Come Together) *Transform (Sliding)
Plate Boundaries
2 plates move away from each other Sea floor spreading, mid ocean ridge is
created (if 2 oceanic plates). New crust is created
Divergent
Occurs when 2 plates collide. 2 continental plates colliding = mountains 2 oceanic plates colliding = ocean trenches
(subduction) Ocean and continental plate colliding = oceanic
plate subducts continental plate. Volcanoes occur.
Convergent Boundary:
2 plates slide past each other horizontally Ex: San Andreas Fault in California (USA) Sudden movement becomes earthquakes
Transform
http://ees.as.uky.edu/sites/default/files/elearning/module04swf.swf
Click the above link to watch pangaea unfold. Look at where volcanoes and earthquakes
commonly occur. Find the plate boundaries and note the
countries on them. Where is Thailand? Is there a connection between land
formations (mountains, volcanoes, earthquakes) and plate boundaries?
Interactive Map:
1. What theory did Alfred Wegner form in the 1800s?
2. What was the single landmass called that broke apart 245 million years ago?
3. What happens at Divergent boundaries?
4. Give 2 pieces of evidence for Continental Drift.
5. If the sea floor spreads and new crust is created, why isn’t the lithosphere getting bigger?
Quiz
He formed the theory of Continental Drift.
It was called Pangaea.
Plates move apart. In the ocean, the is called sea floor spreading. New crust is formed.
1. Rocks the same age were found on both sides of the ocean.2. Tropical plants were found in Arctic zones.
Some oceanic plates are subducting continental plates at Convergent boundaries.The oceanic plate is being destroyed in the asthenosphere.
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