Show:
Density
Continental Drift
Plate Boundaries
Seafloor Spreading
Plate Tectonics
100
What is the mathematical formula for finding Density?
Density equals Mass divided by Volume. (D=M/V)
100
Who was the scientist that came up with the Theory of Continental Drift?
Alfred Wegener
100
List the three categories of Plate Boundaries.
1) Divergent Boundary, 2) Transform Boundaries, 3) Convergent Boundaries
100
What is Seafloor Spreading?
Seafloor spreading is the process that pushes two divergent plates apart. It creates new oceanic crust as the plates are pulled apart.
100
Write a definition for "Plate Tectonics."
Answers will vary, but should be similar to "Earth's crust is made of large sections of rock (plates) that move in respect to each other."
200
Write a definition for the word "Density."
Answers will vary, but should be similar to "density is a ratio of an objects mass to its volume. Density is the amount of matter an object has in relationship to its size."
200
What is the Theory of Continental Drift?
The theory of continental drift says that the continents are in constant motion. They were once all connected in a supercontinent called Pangea.
200
Describe what happens at a Transform Boundary.
At a Transform Boundary, two plates are moving side by side.
200
Where does seafloor spreading occur?
Seafloor spreading occurs at a divergent plate boundary.
200
What is subduction?
Subduction is the process of a denser plate sinking below a less dense plate.
300
What happens to the density of an object if it is heated and expands?
Since the Volume (denominator) increases, the overall density of the object decreases.
300
Identify the four pieces of evidence that Wegener used to support his theory of Continental Drift.
1) The Apparent Fit of Continents (puzzle pieces), 2) Fossil Clues, 3) Rock Clues, 4) Climate Clues
300
Explain what happens at a Divergent Plate Boundary.
At a divergent plate boundary rising heat from the core creates a convection current that brings magma to the surface. The magma solidifies as lava pillows and pushes the two plates apart, creating a mid-ocean ridge.
300
What type of land form is formed by the process of seafloor spreading?
A mid-ocean ridge is formed by seafloor spreading.
300
Explain why there are large trenches along convergent boundaries.
Answers will vary, but should include information about differences in density causing one plate to subduct below the other plate. This subduction causes part of the less dense plate to be dragged down with the denser plate and creates a deep trench.
400
What happens to the density of the asthenosphere as it cools?
As the asthenosphere cools, the molecules slow down and move closer together. This creates a smaller volume, and an overall greater density.
400
Explain how Fossil Clues supports Wegener's Theory of Continental Drift.
Answers will vary.
400
Explain what happens at a Continental-Continental Convergent Plate Boundary.
At a Continental-Continental Convergent Plate Boundary two equally dense plates crash into each other. Since neither plate is denser than the other, neither plate will sink below the other plate. Both plates are uplifted and form a new mountain range.
400
Complete this sentence: "As you travel farther away from a mid-ocean ridge, the rock is ___________ and has _______ sediment built up on top of it."
"As you travel farther away from a mid-ocean ridge, the rock is older and has more sediment built up on top of it."
400
Compare the Lithosphere to the Asthenosphere.
The Lithosphere is the outermost layer of the Earth, while the Asthenosphere is below the Lithosphere. The Lithosphere is very cool and rigid, while the Asthenosphere is hot and similar to molten plastic.
500
Explain how changes in density creates convection currents in the mantle.
Answers will vary, but should include information about the core heating the mantle and causing it to expand and have a smaller density. It then rises toward the crust and cools off. As the mantle cools off, it contracts, becomes more dense, and sinks back toward the core.
500
Explain how two different Climate Clues support Wegener's Theory of Continental Drift.
Answers will vary but must include both Glacial Striations and Coal Deposits.
500
Explain what happens at an Oceanic-Continental Convergent Plate Boundary.
At an Oceanic-Continental Convergent Plate Boundary, two plates come together. The denser plate (oceanic) sinks below the less dense plate (continental). The denser plate subducts and goes back into the mantle.
500
Explain how seafloor spreading supports Alfred Wegener's theory of Continental Drift.
Answers will vary.
500
Explain how convection currents lead to basal drag.
Answers will vary, but should be similar to: The rising material in a convection current hits the lithosphere and moves to the side. As the cooling mantle material is moving to the side, it grabs onto the rigid lithosphere and "drags" it along with the cooling asthenosphere.