Name: ___________________________________________
Period: ____________
Plate Tectonics/Earthquakes/Volcanoes Study Guide
Composition of the Earth
____________________________________ – outermost layer
Continental crust - thicker
Oceanic crust – ___________________________________________________
___________________________________________ – between the crust and core
Core – mantle to _______________________________________ of the Earth
Made of mostly iron but also nickel, sulfur, oxygen
Continental/Oceanic Crust Diagram
Crust/Mantle/Core Diagram
Fill in the blanks
Name: ___________________________________________
Period: ____________
Structure of the Earth
5 main physical layers (breaks down crust, mantle, and core into more specific layers)
_________________________________ – outermost layer (crust and upper part of mantle) “rock sphere”
(1st 60 miles down)
Divided into tectonic plates
Asthenosphere – “_____________________________________ sphere” (60-430 miles)
Hot, flowing, soft layer of mantle where pieces of the lithosphere moved.
_________________________________ – “middle sphere” (430-1800 miles)
Hot, rigid, strong, lower part of mantle (pressure keeps it from flowing)
Extends to core
Lithosphere/Asthenosphere/Mesosphere Diagram
Fill in the blanks
Name: ___________________________________________
Period: ____________
Outer Core – ________________________________________
1,800 to 3,200 miles
Average temp. is 9000 degrees F
____________________________________ Core - solid, dense center of the Earth
3,200 to 3,960 miles
Avg. temp is 12,000 F
Inner Core and Outer Core Diagram
Wegener’s Continental Drift Theory
_________________________________ drift is a theory, by Alfred Wegener, that continents can drift
apart from one another.
He didn’t take into account the ________________________________ __________________________.
He just thought the continents moved.
Name: ___________________________________________
Period: ____________
Pangaea – all _____________________________________ as one
Greek for “all Earth”
Pangaea Picture
Fill in the blank
Tectonic Plates
Plate Tectonics Theory: The theory that the Earth’s ___________________________________________
is divided into tectonic plates that move.
Think jig saw puzzle.
Each plate fits into another one.
Sea floor spreading – process by which new ______________________________________ lithosphere is
created as older materials are pulled away (the sea floor spreads apart).
Name: ___________________________________________
Period: ____________
_________________________________________ form when the tectonic plates collide and they push
the continental crust upward.
Tectonic Plates Diagram
Seismology is the study of _____________________________________.
Seismos means “to _________________________________________” in Greek.
Earthquakes occur near tectonic plate boundaries or faults.
Name: ___________________________________________
Period: ____________
The most ____________________________________________ activity (earthquakes and volcanoes)
occurs along the Ring of Fire, the area that surrounds the Pacific Plate.
Ring of Fire Diagram
A ________________________________________ is a break in the Earth’s crust along which blocks of
the crust slide.
This sliding along the fault is an earthquake.
Types of Motions and Faults
_________________________________ motion occurs where two plates slip past each other
Convergent motion occurs where two plates ___________________________________ together.
_______________________________ motion occurs where two plates pull away from each
Strike slip faults are caused by ___________________________ motion. Blocks of crust slide
______________________________ faults are caused by convergent motion. Blocks of crust
slide vertically.
Normal faults are caused from divergent motion. Blocks of crust move ____________________.
Name: ___________________________________________
Period: ____________
Motion and Fault Chart
Plate Motion
Prominent fault type
Earthquake characteristics
Strike-slip fault
Moderate, shallow
Strong, deep
________________ fault
Normal fault
_______________, shallow
Earthquake Fault/Motion Video
What did the geologist use to demonstration the 3 types of plate motions? _________________________
At the end of the video, in the pot, what did he use to represent the crust of the Earth?
Earthquake Waves
Seismic waves are waves of ________________________ that travel through the Earth from earthquakes.
___________ Waves (primary/pressure) travel through solids, liquids, and gases and are the fastest. (think
push and pull)
________________ Waves (secondary/shear) waves are created when the rock springs back to its original
position after being deformed. (think side to side)
Surface waves move the ground _____________ and _____________________ in circles. (think up and
down like a roller coaster.)
Name: ___________________________________________
Period: ____________
Earthquake Measurement
Seismographs are ____________________________________________located at or near the surface of
the Earth that record seismic waves.
_______________________________________ is a tracing of earthquake motion created by a
Epicenter is the point on the Earth’s surface directly above an earthquakes starting point.
A ____________________________ is the point inside the Earth where the earthquake begins.
Epicenter Picture
Fill in the blanks
Name: ___________________________________________
Period: ____________
Richter Scale
The __________________________________________Scale is used to measure an earthquakes strength
Named after Charles Richter.
Goes from 1 (weakest) to 10 (strongest)
Each time the magnitude increases by 1 unit, the amount of energy released becomes 31.7 times larger.
Earthquakes Study Jams Video
Quiz Score:
__________ / 7
What is a volcano?
A volcano is a ____________________________ that forms when magma is forced to the Earth’s
____________________________________ is magma that flows on the Earth’s surface.
Types of eruptions
Nonexplosive – ______________________ flows
___________________________________: clouds of hot debris and gases shoot out from the volcano
Volcanoes erupt with either lava or ________________________________________________ material.
Lava–created by nonexplosive __________________________________________.
______________________________________: stiff, jumbled heaps of sharp chunks
Name: ___________________________________________
Period: ____________
Pahoehoe: slow forming, like __________________________________ dripping
Aa - pours quickly and has a jagged and brittle crust.
______________________________________________: rounded lumps that form underwater
Pyroclastic material is rock ______________________________________ created by explosive volcanic
Types of Volcanoes
_______________________________________: built out of layers of lava from repeated nonexplosive
eruptions. (wide base, not steep)
Cinder cone: small volcanic cones made entirely of ____________________________________ material
from moderately explosive eruptions. (narrow base, steep)
Composite (stratovolcanoes): most ________________________________________ that form by
explosive eruptions of pyroclastic material followed by quieter outpourings of lava. (wide base, gets
steeper towards the top)
Types of Volcanoes Picture
Name: ___________________________________________
Period: ____________
What causes a volcano?
Rock melts and forms magma when the temperature of the rock increases or when the pressure on the
rock decreases.
Temperature is usually constant (doesn’t change) so _______________________________ usually
causes magma to form.
Magma ______________________________________ because it is less dense than the surrounding rock.
The tectonic plate ___________________________ are where most volcanoes are formed (Ring of Fire).
Formation of Magma Picutre
Earthquakes Study Jams Video
Quiz Score:
__________ / 7

Plate Tectonics/Earthquakes/Volcanoes Study Guide