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)

Rigid 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

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).

Fill in the blank

Name: ___________________________________________ Period: ____________

_________________________________________ form when the tectonic plates collide and they push the continental crust upward.

Tectonic Plates Diagram

Earthquakes

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

Motions

_________________________________ 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 other.

Faults

Strike slip faults are caused by ___________________________ motion. Blocks of crust slide horizontally.

______________________________ 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

Convergent

________________ fault

Strong, deep

Divergent 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 seismograph.

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

Volcanoes

What is a volcano?

A volcano is a ____________________________ that forms when magma is forced to the Earth’s surface.

____________________________________ 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

Eruptions

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 eruptions.

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