Download Plate Tectonic, Earthquakes, and Volcanoes Test Review

Plate Tectonics Unit Study Guide
Describe each layer--
Layers of Composition
Layers of Physical Structure
Crust
Lithosphere
Mostly silicon and oxygen
Continental is thickest
Oceanic is thinnest
Thinnest of all layers
Brittle rock
Hard/rigid
Broken into pieces are called tectonic plates
Mantle
Asthenosphere
Mostly iron and magnesium
Thickest of all layers
“Plasticity”- rock can bend/move without breaking
Less rigid – plasticity. Flows slowly. Soft layer
Mesosphere
Stronger layer- largest section.
Core
Outer Core
Mostly iron and nickel
Divided into two parts
Liquid layer makes our magnetic field
Hot, liquid iron
Inner Core
Hot, solid, and dense iron
1. What are the two types of crust? Which one is most dense? Continental and Oceanic (most dense)
2. Oceanic crust is most similar to _basalt____ , and continental crust is most similar to _granite____.
3. Which layer means “Rock sphere”? “Weak sphere”? “Middle Sphere”?
Lithosphere
Asthenosphere
Mesosphere
4. Who discovered the theory of continental drift? When did he do this?
Alfred Wegener (early 1900’s)
5. What are the three pieces of evidence that he used to support his theory? Give examples.
1. Landforms from other continents fit well together like puzzle pieces (South America/Africa)
2. Found the same fossil species on multiple continents that are separated by large bodies of water
(Glossopteris, Mesosaurus, or Lystrosaurus)
3. Some fossils were found in a completely different climate than which they required to thrive
(tropical plants found in Arctic)
6. What is Pangaea? How long ago had it formed?
300 million years ago all the landmasses of today were joined together in a single landmass
7. What sea surrounded Pangaea (means “all sea”)? Panthalassa
8. What was right and wrong about the Continental Drift theory?
Right—Continental Drift explained that landmasses we have today were not like that long ago—
the Earth’s surface is moving
Wrong—No explanation about how they move was given- just observations that they do. Also, the
continents are not “drifting” apart from the ocean floor
9. What major discovery in the mid 1900’s made scientists revise our theory of “drifting continents”?
Mid-ocean ridges—discovered that the ocean floor is actually changing too!
10.
Sea Floor Spreading
Feature Description:
Mid-Ocean Ridges…underwater mountain
ranges. Longest mountain ranges on Earth.
Subduction
Feature Description:
Trenches…deep underwater canyons. Deepest
spots in all of the oceans.
Plate Boundary:
Divergent
Plate Boundary:
Convergent
Additional Facts:
New crust is created when the two plates move
away from each other. Older rock is pushed away
from ridges.
Additional Facts:
When two plates collide, the densest one gets
pulled underneath where it will remelt into the
mantle. Destroys crust.
11. The (newest/ oldest) crust is farthest away from the mid-ocean ridges.
12. How do oceanic magnetic stripes provide proof of sea floor spreading?
When new oceanic crust is still molten, the magnetic grains will align with the magnetic poles (like
a compass). Throughout Earth’s history, the poles have reversed several times, so the direction of
alignment changes too. Giving us multiple “stripes” on the ocean floor. This proves that the ocean
floor has been changing and growing throughout earth’s history—not all formed at once.
13. How is our current Plate Tectonics Theory different from the Continental Drift Theory?
Plate Tectonics allows for explanation about how the Earth’s crust is moving. It explains that both
continental and oceanic crust is moving as “plates”. Where they split apart new crust is made and
where they collide old crust is destroyed. This movement is steady and slow. Its being driven by
convection currents that move the mantle beneath the crust.
Continental Drift could not provide any explanation for why they move and only believed the
continents move, not the ocean.
14. The heat source for the convection currents in the mantle is the __core____________.
15. Warm materials (rise/ sink) and cooler materials (rise/ sink). This motion creates a _circular motion__.
16. How is plate movement measured each year (meters, centimeters, millimeters, kilometers)?
Plate Tectonics Study Guide II
The test on Thursday will consist of two parts:
 Main Test (multiple choice, true/false, matching)
 Drawings
The first study guide will help you prepare for the first component.
On the test, you will be expected to draw some illustrations of the three types of plate boundaries. You will be
expected to label the main parts, and neatness will definitely count!!
Below, I’ve given you room to draw your pictures. Don’t forget your labels and also write the words from the word
bank below next to the boundary picture.
_____________________________________________________________________________________________
For each plate boundary, you must draw a diagram representing the plate motion. Draw arrows to show the
direction of motion. Also, you must write which words from the “word bank” below are associated with that
boundary.
Volcanoes
Trench
Earthquakes
Tsunamis Mid-Ocean Ridges
San Andreas Fault
Mid-Atlantic Ridge
Mountains
Himalayas
Mariana Trench
Makes New Crust
Subduction Zones
1. Divergent Boundary:
3. Convergent Boundary: ~Oceanic/Continental
2. Transform Boundary:
4. Convergent Boundary:
~Continental/ Continental
Destroys Crust