LAB 3: FORCES THAT CAUSE EARTH MOVEMENTS Key Question: Does the rock of the Earth’s mantle move?
Plasticity Today, you will see what happens to a material that has plasticity (the ability to flow) when it is heated from below
Observations The corn syrup warmed & bubbled on the bottom of the pan in the center. The warmed corn syrup rose causing the cardboard to move apart very slowly. This is a model of convection.
*CONVECTION CURRENT* Convection Animation
CONVECTION : When a substance moves because it is heated from below and cooled from above. Warm less dense material rises while cooler more dense material sinks.
Convection in the Mantle: Mid-Ocean Ridge
Earth vs. Model When comparing our model to the earth, what do the following parts of your model represent? The heat source (candle): Core The moving syrup: Mantle Convection The cardboard pieces: pieces of the Earth’s crust Plate Tectonics
Sea Floor Spreading
Mid-Ocean Ridge
Iceland
LAB 3: FORCES THAT CAUSE EARTH MOVEMENTS Key Question: Does the rock of the Earth’s mantle move? Yes, the rock of the earth’s mantle is a solid but it has plasticity (or the ability to flow)
The outermost layer of the Earth is the crust. The Earth’s crust (lithosphere) is like a puzzle. It is made up of a series of plates (Lithospheric plates) that move around the earth slowly due to convection in the mantle (more specifically the asthenosphere)
Plate Tectonics Is the theory that the earth’s crust is broken into plates that move and interact with each other These plates interact with each other at Plate boundaries (areas where plates meet)
There are 3 main types of plate boundaries: Divergent Convergent Transform
Plate Boundaries animations along plate boundaries. Plate Boundary Map - GEOLOGY.COM
Divergent Plate Boundaries Where lithospheric plates move away from each other and new crust is formed Convergent Plate Boundaries Where lithospheric plates move toward each other and collide Transform Boundaries Where lithospheric plates slide/grind past each other side- by-side
LAB 4: Movement of the earth’s lithospheric plates Key Question: What happens where lithospheric plates meet?
Divergent Plate Boundaries Where lithospheric plates move away from each other and new crust is formed CAUSES SEA-FLOOR SPREADING
Convergent Plate Boundaries Where lithospheric plates move toward each other and collide 3 Types Ocean – Ocean Convergence Ocean – continent Convergence continent – continent Convergence
Continental Crust Thicker, less dense lithospheric plate Vs. Oceanic Crust Thinner, more dense lithospheric plate
Ocean plate is subducted below continent. Subduction: The movement when one plate (oceanic crust) dives below another plate A trench forms above the subduction zone in water A volcanic mountain chain forms on land Ocean – continent Convergence
One Plate Subducts Subduction: The movement when one plate (oceanic crust) dives below another plate A trench forms above the subduction zone in water A volcanic island arc forms on the plate that is not subducted Ocean – Ocean Convergence
Ring Of Fire
No subduction because continents are less dense than the mantle Continents collide and fold up (crunch) to form mountains continent – continent Convergence
Ocean – Continent Convergence 1. A. When an ocean plate converges with a continental plate, what happens? (Which plate subducts?) Explain. B. What is a subduction zone? C. What feature is found on the earth directly above the subduction zone? D. What feature forms on land? Explain.
Ocean – ocean Convergence 2.A. When two ocean plates collide, what happens? B. What feature is found on the earth’s surface directly above the subduction zone? C. What feature forms on the ocean plate that is not subducted? Explain.
Continent– Continent Convergence 3.A. When two continents collide, what happens? B. What feature forms on the earth’s surface because of the collision? C. Why don’t continents go down at the subduction zones?
Transform Boundaries Where lithospheric plates slide/grind past each other side-by-side
The San Andreas Fault is a TRANSFORM Fault