1. Chapter 17 Review

2. What was the name of the early mapmaker that looked at coastlines?
Abraham Ortelius
What early scientist discussed that the southern continents were once together and what did he call them?
Edward Seuss
Gondwanaland
What was the name of Alfred Wegener’s idea?
Continental Drift

3. What was the Wegener’s supercontinent called?
Pangaea
How long ago did this supercontinent break up?
200 million years ago
What were Wegener’s major pieces of evidence?
Climate evidence (Glossopteris)
Animal fossil (Lystrosaurus)

4. What was Wegener’s 2 missing pieces?
Where are the tears
How are the continents moving
What technology came along to help Wegener?
Sonar
What did Harry Hess come up with to help?
Seafloor spreading
What are mid-oceanic ridges and what is happening there?
The “tears” on the ocean floor/new crust created

5. What are trenches and what is going on there?
Deepest parts of Earth/old crust is being destroyed
What are plates?
Large slabs of Earth’s crust that move
What are plate boundaries?
Where the plates meet each other and interact
List the 3 plate boundaries and explain each.
Convergent – plates coming together
Divergent – plates spreading apart
Transform – plates slide past one another

6. List the 3 types of convergent plate boundaries:
Continental/Continental – cause mountains
Oceanic/Continental – can cause volcanoes
Oceanic/Oceanic – can cause volcanoes
What is mantle convection?
Movement of magma under the crust that is caused by temp differences
How do scientists believe the plates move?
They move along with the “currents” from mantle convection

7. What is a subduction zone?
What is ridge push?
Happens along ridges as convection current “push” plates apart
What is slab pull?
Happens at trenches where the convection currents “pull” slab/plates into Earth
What is a subduction zone?
Area at a trench or oceanic/continental and oceanic/oceanic plate boundaries where slab pull is occurring