Volcanoes and Earthquakes Topic: Earthquake Magnitude Objectives: Day 1 of 4Objectives: Day 1 of 4 –I will review the definition of an earthquake –I.

Volcanoes and Earthquakes

Volcanoes and Earthquakes

Topic: Earthquake Magnitude Topic: Earthquake Magnitude• Objectives: Day 1 of 4Objectives: Day 1 of 4

– I will review the definition of an earthquakeI will review the definition of an earthquake– I will know the difference between the focus I will know the difference between the focus

and epicenterand epicenter– I will understand the different ways we I will understand the different ways we

measure earthquakesmeasure earthquakes

Unit: Earthquakes & Volcanoes Unit: Earthquakes & Volcanoes

Quick Write:Quick Write:Answer a question of your choice in 2-3

sentences:• How many earthquakes do you think we get a day How many earthquakes do you think we get a day

in California??????in California??????

• What do you think would happen if a major What do you think would happen if a major earthquake struck Roseville????earthquake struck Roseville????

• What do you know about earthquakes????What do you know about earthquakes????

Breaking RockBreaking RockBreaking RockBreaking Rock• Stress on rock is Stress on rock is

greatest at plate greatest at plate boundariesboundaries

• When rock breaks, it When rock breaks, it forms a faultforms a fault

• Rocks break and Rocks break and move along flat move along flat surfaces called surfaces called faultsfaults

Fault

What is a Fault?What is a Fault?

• Rocks break Rocks break and move and move along ____ along ____ surfaces called surfaces called faultsfaults

Fault

Answer Bank

WavesaboveFlat

locating31

Focusinside

flat

Breaking RockBreaking RockBreaking RockBreaking Rock• When faults break they When faults break they

release energy in the form release energy in the form of seismic waves of seismic waves

• These waves cause the These waves cause the ground shake creating an ground shake creating an earthquakeearthquake

• An Earthquake is the An Earthquake is the movement of the ground movement of the ground caused by waves of caused by waves of energy released as rocks energy released as rocks move along faultsmove along faults

Seismic Waves

Stress on rock is greatest at Plate BoundariesStress on rock is greatest at Plate Boundaries

= Earthquakes

What is an Earthquake?What is an Earthquake?What is an Earthquake?What is an Earthquake?

• The movement of the ground The movement of the ground caused by ______ of energy caused by ______ of energy released as rocks move along released as rocks move along faultsfaults

• Earthquakes happen at plate Earthquakes happen at plate boundaries where stress on boundaries where stress on rock is greatestrock is greatest

Answer BankWavesaboveFlat

locating31

Focusinside

waves

Focus!!!!!Focus!!!!!Focus!!!!!Focus!!!!!• The location where The location where

earthquakes originate earthquakes originate is called the is called the focusfocus

• Focus: The point or Focus: The point or location inside the location inside the earth’s interior where earth’s interior where energy is releasedenergy is released

• It is the location It is the location where earthquakes where earthquakes originate (focus) originate (focus) producing producing seismic seismic waveswaves

Focus

Epicenter!!!!!Epicenter!!!!!Epicenter!!!!!Epicenter!!!!!• As we just learned,

the focus of an earthquake lies below the surface

• The point on the earth’s surface directly above an earthquake’s focus is the epicenterepicenter

Focus

Epicenter

What is the difference between the FocusFocus and the Epicenter

What is the difference between the FocusFocus and the Epicenter

• FocusFocus is the point ______ the is the point ______ the earth’s interior where earthquake earth’s interior where earthquake energy is releasedenergy is released

• Epicenter Epicenter is the point or location is the point or location directly above an earthquake’s focusdirectly above an earthquake’s focus

• Please draw:Please draw:

Answer BankWavesaboveFlat

locating31

Focusinside

inside

1 – 1.91 – 1.9Not felt, but

can be recorded>600,000 per year

2 – 3.92 – 3.9Can be felt,

damage begins>400,000 per year

4 – 4.94 – 4.9 Can be Strongly felt, Same energy as a

strong tornado About 14,000 per year

Insignificant

Minor

Small

6 – 6.96 – 6.9Can be damaging

In wealthy countries,Same energy as a nuclear explosion About 110 per year Moderate

5 – 5.95 – 5.9 Can be damaging in poor countries,

About 1,500 per yearStrong

7 – 7.97 – 7.9 Can cause serious damage and loss of life

Same energy as MountSt. Helens EruptionAbout 12 per year

8 – 9.58 – 9.5Cause serious damage

Great earthquakes 0 - 1 per year

Major

Great

Largest Known EarthquakeChile Magnitude 9.5

Magnitude

Earthquake MagnitudeEarthquake Magnitude

• To measure the To measure the amount of energy amount of energy released from an released from an earthquake, earthquake, scientists us the scientists us the Richter ScaleRichter Scale

• The Richter scale The Richter scale measures the measures the magnitude or amount magnitude or amount of energy released of energy released from an earthquakefrom an earthquake

• Thousands of Thousands of Earthquakes happen Earthquakes happen everyday but only the everyday but only the destructive destructive earthquakes receive earthquakes receive attentionattention

• The graph to the right The graph to the right displays earthquake displays earthquake magnitude & the magnitude & the number of number of earthquakes earthquakes worldwideworldwide

-1 0 1 2 3 4 5 6 7 8 9

1,000,000

500,000

10,000

1,000

100

10

1

Num

ber

of

Eart

hquake

s e

very

year

-1 0 1 2 3 4 5 6 7 8 9

Insignificant

Minor

Small

Moderate

Strong

Major

Great

Magnitude

A magnitude 8 is 31 times more powerfulThan a magnitude 7

A magnitude 7 is 31 times more powerfulThan a magnitude 6

A magnitude 6 is 31 times more powerfulThan a magnitude 5

Earthquake MagnitudeEarthquake Magnitude

1,000,000

500,000

10,000

1,000

100

10

1

Num

ber

of

Eart

hquake

s e

very

year

• How many more How many more times powerful is times powerful is an earthquake with an earthquake with

a magnitude a magnitude 88 than than an earthquake with an earthquake with

a magnitude a magnitude 55??????

Answer:31 x 31 x 31 = 29,791 times

more powerful!!!!!

What is the Richter Scale?What is the Richter Scale?What is the Richter Scale?What is the Richter Scale?

• A measure of the energy or A measure of the energy or magnitude released at the ______ of magnitude released at the ______ of an earthquakean earthquake

• Magnitude 8 is ___ times more Magnitude 8 is ___ times more powerful than a magnitude 7powerful than a magnitude 7

• 1-2 = weak not felt1-2 = weak not felt

• 7- 9 = Highly destructive7- 9 = Highly destructive

Answer BankWavesaboveFlat

locating31

Focusinside

31

focus

Mercalli ScaleMercalli Scale• The Mercalli scale.

Invented by Giuseppe Mercalli in 1902 uses the observations of the people who experienced the earthquake to estimate its intensity and epicenter

• The great 1906 San Francisco took place long before the Richter scale was invented

• So how do we know the strength of the earthquake?

• By the Mercalli Scale!!!!

• I.I. People do not feel any Earth movement.

• II.II. A few people might notice movement if they are at rest and/or on the upper floors of tall buildings.

• III. Many people indoors feel movement. Hanging objects swing back and forth. People outdoors might not realize that an earthquake is occurring

• IV.IV. Most people indoors feel movement. Hanging objects swing. Dishes, windows, and doors rattle. The earthquake feels like a heavy truck hitting the walls. A few people outdoors may feel movement. Parked cars rock.

• V.V. Almost everyone feels movement. Sleeping people are awakened. Doors swing open or close. Dishes are broken. Pictures on the wall move. Small objects move or are turned over. Trees might shake. Liquids might spill out of open containers.

Mercalli ScaleMercalli Scale I

II

IIIIV

V

III

III

IV

IV

V

V

II

• VI.VI. Everyone feels movement. People have trouble walking. Objects fall from shelves. Pictures fall off walls. Furniture moves. Plaster in walls might crack. Trees and bushes shake. Damage is slight in poorly built buildings. No structural damage.

• VII.VII. People have difficulty standing. Drivers feel their cars shaking. Some furniture breaks. Loose bricks fall from buildings. Damage is slight to moderate in well-built buildings; considerable in poorly built buildings.

• VIII.VIII. Drivers have trouble steering. Houses that are not bolted down might shift on their foundations. Tall structures such as towers and chimneys might twist and fall. Well-built buildings suffer slight damage. Poorly built structures suffer severe damage. Tree branches break. Hillsides might crack if the ground is wet. Water levels in wells might change

Mercalli ScaleMercalli Scale

VI

VIIVIII

VI

VII

Mercalli ScaleMercalli Scale

• IX.IX. Well-built buildings suffer considerable damage. Houses that are not bolted down move off their foundations. Some underground pipes are broken. The ground cracks. Reservoirs suffer serious damage.

• X.X. Most buildings and their foundations are destroyed. Some bridges are destroyed. Dams are seriously damaged. Large landslides occur. Water is thrown on the banks of canals, rivers, lakes. The ground cracks in large areas. Railroad tracks are bent slightly.

• XI.XI. Most buildings collapse. Some bridges are destroyed. Large cracks appear in the ground. Underground pipelines are destroyed. Railroad tracks are badly bent.

• XII.XII. Almost everything is destroyed. Objects are thrown into the air. The ground moves in waves or ripples. Large amounts of rock may move.

X

XIXII

IX

IX

X

What is the What is the Mercalli Intensity Mercalli Intensity Scale?Scale?

What is the What is the Mercalli Intensity Mercalli Intensity Scale?Scale?

• A way of measuring and _______ earthquakes based on eyewitness observations, damage reports and ground motion

Answer BankWavesaboveFlat

locating31

Focusinside

locating

TsunamisTsunamisTsunamisTsunamis• A tsunami is a giant A tsunami is a giant

wave created by an wave created by an underwater earth quakeunderwater earth quake

• When a fault is near the When a fault is near the ocean surface, it can ocean surface, it can displace the water, displace the water, generating a huge wavegenerating a huge wave

• These waves only These waves only become dangerous as become dangerous as they approach shore they approach shore

What is a What is a Tsunami?Tsunami?What is a What is a Tsunami?Tsunami?

• A giant wave created by A giant wave created by an underwater earth an underwater earth quakequake

Answer BankWavesaboveFlat

underwater31

Focusinside

Summarize:Summarize:

• The ____ of an earthquake is inside the The ____ of an earthquake is inside the earth and the ______ is above the focusearth and the ______ is above the focus

• The Richter scale measures the amount of The Richter scale measures the amount of ____ released from an earthquake____ released from an earthquake

• A magnitude 9 is _____ times more powerful A magnitude 9 is _____ times more powerful than a magnitude 8. than a magnitude 8.

• The Mercalli scale is based on ______ The Mercalli scale is based on ______ reportsreports

Answer Bank31

EyewitnessFocus

Epicenterenergy

Topic: Seismic Waves & Triangulation

Topic: Seismic Waves & Triangulation

• Objectives: Day 2 of 4Objectives: Day 2 of 4– I will know the 3 types of seismic wavesI will know the 3 types of seismic waves– I will know how scientists find the epicenter I will know how scientists find the epicenter

of an earthquake using the different speed of of an earthquake using the different speed of seismic wavesseismic waves

– I will understand triangulation and how it is I will understand triangulation and how it is used to find earthquake locationused to find earthquake location

Unit: Earthquakes & Volcanoes Unit: Earthquakes & Volcanoes

Quick Write:Quick Write:Answer a question of your choice in 2-3

sentences:• Where do you think the safest place to be is during an Where do you think the safest place to be is during an

earthquake??????earthquake??????

• How you ever felt an earthquake??? Describe the How you ever felt an earthquake??? Describe the Experience?Experience?

• If you drop a rock in a pond, what happens to the water?If you drop a rock in a pond, what happens to the water?

• What are some famous earthquakes or tsunamis you have What are some famous earthquakes or tsunamis you have heard of????heard of????

Seismic Waves Seismic Waves • Waves are all around

us, light waves, ocean waves, and sound waves

• If you throw a pebble in a lake, the waves or energy will move out in all directions

• Another kind of wave are Seismic Waves

• Seismic Waves are generated or created by earthquakes

Focus

Epicenter

Seismic Waves

• Energy waves that move outward from an Energy waves that move outward from an earthquake’s _____ causing the ground to earthquake’s _____ causing the ground to Shake!Shake! Answer Bank

Focus3

GreaterSlower faster

What are What are Seismic Waves?Seismic Waves?What are What are Seismic Waves?Seismic Waves?

focus

Seismic WavesSeismic Waves• When an earthquake goes off it

releases seismic waves• 3 types of seismic waves exist:

Primary, Secondary, and Surface

• Primary wavesPrimary waves are the fastest waves and cause rock to compress and stretch rock

• Secondary wavesSecondary waves are slower than primary waves and move rock up and down

• Surface wavesSurface waves are the most destructive because they travel through rock at the surface causing rock to move up and down and side to side

What are the 3 types of Seismic Waves???What are the 3 types of Seismic Waves???What are the 3 types of Seismic Waves???What are the 3 types of Seismic Waves???

• Primary wavesPrimary waves are the fastest waves, cause rock to compress and stretch

• Secondary wavesSecondary waves are ______ than p-waves and move rock up and down

• Surface wavesSurface waves most destructive, travel along the surface and move rock up and down, side to side

Answer Bankfasterslowerfocusslower

Recording Seismic WavesRecording Seismic Waves

• After an earthquake seismic waves are released

• Seismic stations record these earthquakes with a seismograph

• These seismographs record P waves first since they are the fastest, the S-Waves second, and the destructive surface waves last

P-Waves S-Waves

Surface-Waves

P-Waves S-Waves

Surface-Waves

What is Seismograph?What is Seismograph?What is Seismograph?What is Seismograph?

• Instrument to record Instrument to record seismic waves from an seismic waves from an earthquakeearthquake

• It records p-waves first, s-It records p-waves first, s-waves______, and surface waves______, and surface waves lastwaves last

• Please draw & label seismograph below:Please draw & label seismograph below:Answer Bank

FocussecondGreaterSlower Faster

P-Waves S-Waves

Surface-Waves

P-Waves S-Waves

Surface-Waves

second

Distance To Earthquake EpicenterDistance To Earthquake Epicenter

• Scientists use the seismograph to locate the epicenter of an earthquake

• Remember, the P-wave is faster and arrives first at a seismic station

• Every Seismograph records a time delay between the P and S and waves

• The farther from the earthquake epicenter, the greater the time delay

• This time delay between the P and S wave is used to find the distance to the earthquake epicenter P-Waves S-Waves

Surface-Waves

P-Waves S-Waves

Surface-Waves

P-WaveP-WaveArrival TimeArrival Time

S-WaveS-WaveArrival TimeArrival Time

S-P Time Delay =Distance to Epicenter

Distance To Distance To EpicenterEpicenter

Distance To Distance To EpicenterEpicenter

---------- = S - waves--------- = P - waves

P-Waves

Epicenter

Distance toDistance to EpicenterEpicenter

Distance toDistance to EpicenterEpicenter

S-Waves

Seismic Station

Epicenter

S-P Time Delay =Distance to Epicenter

The time delay between the

SS and PP wave gives us the Distance to the epicenter

In other words, S-P Time Delay = Distance to Epicenter

Seismic

Station A

P-Wave S-Wave

Distance toDistance to EpicenterEpicenter

Distance toDistance to EpicenterEpicenter

What is the What is the S – P Time Delay IntervalS – P Time Delay Interval??What is the What is the S – P Time Delay IntervalS – P Time Delay Interval??

• Time Delay between the Time Delay between the PP and and SS waves on a seismographwaves on a seismograph

• This time delay equals the distance to This time delay equals the distance to the epicenterthe epicenter

• The farther from the epicenter, the The farther from the epicenter, the ______ the time delay______ the time delay

Answer BankFocus

3 GreaterSlower faster

greater

Epicenter

Seismic

Station A

Seismic

Station B

Seismic

Station C

P-Wave S-Wave

P-Wave S-Wave

P-WaveS-Wave

Epicenter

TriangulationTriangulationTriangulationTriangulation

What is What is TriangulationTriangulation??What is What is TriangulationTriangulation??

• Method used to locate an earthquake Method used to locate an earthquake epicenter using 3 seismic stationsepicenter using 3 seismic stations

• The ________ is located where all 3 The ________ is located where all 3 circles intersectcircles intersect

• Radius of each circle = distance to Radius of each circle = distance to epicenterepicenter

Answer BankFocus

3 GreaterSlower Faster

distanceepicenter

epicenter

EpicenterEpicenterEpicenterEpicenterEpicenterEpicenter

---------- = S - waves--------- = P - waves

EpicenterEpicenter

OnlyOnly P-wavesP-waves RecordedRecorded

PP andand SS WavesWaves RecordedRecorded

S-waves cannot pass through liquid, and are not recorded around the world

An earthquake releases Seismic Waves--P & S waves P-waves have the ability to pass through the core, liquid outer core, and mantle whereThey are recorded at Seismic stations around the world

Because S-Waves Cannot Pass through liquid, we know the earth’s outer core is liquid Iron Shadow ZoneShadow Zone

LiquidOuterCore

LiquidOuterCore

Mantle Core Mantle

Earth’s InteriorEarth’s InteriorEarth’s InteriorEarth’s Interior

PP andand SS WavesWaves RecordedRecorded

How do we know the outer How do we know the outer core is made of Liquid Iron?core is made of Liquid Iron?How do we know the outer How do we know the outer core is made of Liquid Iron?core is made of Liquid Iron?

• Because S-waves cannot pass Because S-waves cannot pass through ______creating a through ______creating a shadow zone where no S-waves shadow zone where no S-waves are recorded are recorded

Answer BankFocusliquid

GreaterSlower Fasterpass

liquid

Who’s Been Listening?Who’s Been Listening?Not a summary!!!!!!Not a summary!!!!!!

Who’s Been Listening?Who’s Been Listening?Not a summary!!!!!!Not a summary!!!!!!

D

1.1. Letter _______ represents the deadly surface wavesLetter _______ represents the deadly surface waves2.2. Letter _______ represents the time delay between Letter _______ represents the time delay between the primary and secondary wavesthe primary and secondary waves3. Letter _______ represents the fast primary waves3. Letter _______ represents the fast primary waves4. Letter _______ represents the slower secondary waves4. Letter _______ represents the slower secondary waves

Summarize:Summarize:• Seismic stations farther from the

epicenter record a greater S-P time delay• _____ seismic station are needed to

locate an earthquake _______• The radius of each circle equals the The radius of each circle equals the

______ from the seismic station to the ______ from the seismic station to the epicenterepicenter

• The epicenter is located where all three The epicenter is located where all three _____ intersect_____ intersect

Answer Bank3

CirclesDistanceepicenter

Volcanoes and Earthquakes

Volcanoes and Earthquakes

Topic: Topic: Volcano Locations & Magma Composition Topic: Topic: Volcano Locations & Magma Composition

Objectives: Day 1 of 4– I will understand the 3 locations where

volcanoes can be found– I will know how magma composition

effects whether a volcano will erupt violently or quietly

– I will know how silica effects the viscosity or thickness of magma

Unit: Unit: Earthquakes & Volcanoes

Quick Write:Quick Write:Quick Write:Quick Write:Answer a question of your choice in 2-3

sentences:• Have you or your family ever visited a volcano? If

so where at? Describe the experience:• How do volcanoes grow in size????• What do you think volcanoes are made of?????• Where do you think volcanoes form at???• What do you think makes a volcano erupt with

deadly explosive force???• Why do you think soda cans explode when you

shake them up???

• A volcano is an opening in the earth’s surface that often forms a mountain when layers of lava and ash build up over time

Volcanoes and YouVolcanoes and You Volcanoes and YouVolcanoes and You

What is a Volcano?What is a Volcano?What is a Volcano?What is a Volcano?

• An opening in the earth’s surface that forms a mountain as ______of lava and ash build up over time

Answer Bankapart

constantrises

collidelayers

layers

Volcano LocationsVolcano LocationsVolcano LocationsVolcano Locations

• Volcanoes form at:- Divergent plate boundaries Here plates pull apart as new magma rises

(Ex—Iceland)- Convergent plate boundaries

Here plates collide and one plate subducts where it melts feeding volcanoes at the surface

(Ex—Mt. St. Helens WA)-Hot spots

Here a constant steady flow of magma rises to the surface to form volcanoes

(Ex—Hawaii)

Volcano Volcano LocationsLocationsVolcano Volcano LocationsLocations

•Volcanoes form at:- Divergent plate boundaries Here plates pull apart as new magma rises

(Ex—Iceland)

Iceland Iceland Hot SpringsHot SpringsIceland Iceland Hot SpringsHot Springs

Volcano LocationsVolcano Locations

• Volcanoes form at:- Convergent plate boundaries

Here plates collide & one plate subducts where it melts feeding volcanoes at the surface (Ex—Mt. St. Helens)

Cascade VolcanoesCascade Volcanoes Cascade VolcanoesCascade Volcanoes

• From Northern California up to Canada lies a series of volcanoes called the Cascade Mountain Range

• Here the Juan de fuca plate subducts under the north American plate forming a series of volcanoes

• As the Juan de fuca plate subducts, it melts, feeding the volcanoes at the surface froming the cascade volcanoes

Volcano Volcano LocationsLocationsVolcano Volcano LocationsLocations

•Volcanoes form at:- Hot Spots

Here a constant steady flow of magma rises to the surface to form volcanoes(Ex—Hawaii)

Hot SpotsHot SpotsHot SpotsHot Spots

Lithospheric Plate

Ocean

• Hawaii formed as the Pacific plate slowly moved over a Hot Spot

• Over Ten Million Years, A chain of Islands formed

Stationary Hot Spot

Where are the 3 locations Where are the 3 locations volcanoes form?volcanoes form?

Where are the 3 locations Where are the 3 locations volcanoes form?volcanoes form?

- Divergent plate boundaries Plates pull apart as new magma rises

(Ex—Iceland)- Convergent plate boundaries

Plates collide and one plate subducts where it melts feeding volcanoes at the surface

(Ex—Mt. St. Helens WA)-Hot spots

Pacific plate moves over a________steady flow of magma rises to the surface to form a chain of volcanoes (Ex—Hawaii)

Answer Bankapart

constantrises

subductslayers

constant

= Volcanoes

Ring of FireRing of FireRing of FireRing of Fire• Convergent plate

boundaries are located all around the Pacific Rim

• Because of this, volcanoes are located all around the Pacific Ocean

• These volcanoes make up the Ring of Fire

What is the Ring of Fire?What is the Ring of Fire?What is the Ring of Fire?What is the Ring of Fire?

• A chain or ring of volcanoes ______ the pacific ocean created by convergent boundaries

Answer Bankapart

constantrises

Collidearoundlayers

2 Types of Eruptions2 Types of Eruptions

• Some volcanic eruptions are explosive, & violent and while others are non-explosive erupting quietly

• For example, Mt. Saint Helens erupt violently (explosive)

• Kilauea in Hawaii erupts quietly (non-explosive)

Explosive!

Non-Explosive

What are the 2 types of Volcanic Eruptions?What are the 2 types of Volcanic Eruptions?

-Explosive, ______eruptions:

(Ex: Mt. Saint Helens)

-Non-Explosive, quiet eruptions (Ex: Kilauea)

Answer BankTrapssilicaQuiet

Releasesgasesviolent

violent

Magma CompositionMagma Composition• Why do some

volcanoes erupt explosively and others non-explosively?

• It has to do with 3 factors:*The amount of trapped gases in the magma

*Viscosity or thickness of the magma

*Silica content

Rhyolitic Magma = Explosive Eruptions

Basaltic Magma = Non-Explosive Eruptions

What factors make volcanoes explosive?What factors make volcanoes explosive?

• Amount of trapped gases in the magma

• Viscosity or thickness of magma

• ______ content

Answer BankTrapssilicaQuiet

Releasesgasesviolent

Silica

Magma CompositionMagma Composition Magma CompositionMagma Composition

•Rhyolitic Felsic magma is high in silica, therefore it has a high viscosity (thick) and traps gases producing violent explosive eruptions

•Basaltic Mafic (dark

color) magma is low in silica, therefore it has a low viscosity and releases gases producing quiet non-explosive eruptions

Rhyolitic Magma = Explosive Eruptions

Basaltic Magma = Non-Explosive Eruptions

What is the difference between What is the difference between Rhyolitic and Basaltic magma?Rhyolitic and Basaltic magma?

What is the difference between What is the difference between Rhyolitic and Basaltic magma?Rhyolitic and Basaltic magma?

• Rhyolitic magma: – High in silica – High Viscosity (thick)– Traps gases (increasing pressure)– creates violent, explosive eruptions

• Basaltic magma: – Low in silica– Low Viscosity (Very fluid)– ________ gas (reducing pressure)– creates quiet, non-Explosive

eruptions

Answer BankTrapssilicaQuiet

Releasesgasesviolent

Releases

Who has been listening?Who has been listening?Which one has the most silica?Which one has the most silica?Which one has the least silica?Which one has the least silica?

Who has been listening?Who has been listening?Which one has the most silica?Which one has the most silica?Which one has the least silica?Which one has the least silica?

Basaltic Rhyolitic1. Which magma

traps gases?

2. Which magma Releases gases?

3. Which magma contains more silica?

Silica Silica

Summarize!Summarize!

Explosive Eruptions?

High in Silica?

Traps gases?

High or low Viscosity?

Example

Rhyolitic ___ Yes ___ ____ Viscosity

Mt. St.

Helens

Basaltic ___ No ___ ____

Viscosity

Kilauea

Hawaii

Answer BankThickHighsilica

viscosityYes(2)Fluidlow

No(2)

Volcanoes and Earthquakes

Volcanoes and Earthquakes

Topic: Volcano Types Topic: Volcano Types

Objectives: Day 2 of 4

– To understand the differences between the 3 major types of volcanoes

– To understand how magma affects the shape and steepness of a volcano

Unit: Volcanoes& Earthquakes

Quick Write:Quick Write:Answer a question of your choice in 2-3

sentences:• Have you ever visited a volcano? Was it big or

small? Steep or flat sloping?

• What are some famous volcanoes you have heard of? Are they large or small in size?

Types of VolcanoesTypes of Volcanoes

• There are three basic types:– Cinder Cone Volcano– Composite Volcano– Shield Volcano

What are the 3 types of Volcanoes?What are the 3 types of Volcanoes?

– Cinder Cone Volcano– Composite Volcano– Shield Volcano

0.5 miles wide

Cinder Cone Volcanoes

Cinder Cone Volcanoes are made of cinder (hot rock) and ash

The eruption of cinder produces very steep sided volcanoes

Because of their size, cinder cone eruptionsare not considered hazardous

Paricutin Cinder Cone, Mexico

Paricutin Cinder Cone, Mexico

Sunset CraterCinder Cone,Arizona, USA

Sunset CraterCinder Cone,Arizona, USA

What is a Cinder Cone Volcano?What is a Cinder Cone Volcano?

-____ in size-Made of layers Cinder (hot rock) and ash which produce _____slopesEx. Paracutin Mexico (Draw picture below)

Answer basalticSteepSmall

Rhyolitic

0.5 miles wide

20 miles wide

Composite VolcanoesComposite VolcanoesComposite Volcanoes are made of layers of

ash and High viscosity lava

The thicker, high viscosity magma gives Composite volcanoes relatively steep slopes

Thick high viscosity Rhyolitic lava traps gases producing explosive, violent eruptions

Mt. Saint Helens,

Composite Volcano,

Washington, USA

Mt. Saint Helens,

Composite Volcano,

Washington, USA

Mt. Fuji, Composite Volcano, JapanMt. Fuji, Composite Volcano, Japan

What is a Composite Volcano?What is a Composite Volcano?

-Volcano Made of layers Ash, and _____(thick) lava which produce moderately steep slopes-Thick, ____viscosity magma traps gases producing very explosive & violent eruptionsEx. Mt. St. Helens (Draw picture below)

AnswerBank small

massivebasalticrhyolitic

high

20 miles wide

Shield Volcanoes are large and flat in shape made only of layers of lava that travel long distances

Magma from shield volcanoes is very fluid and runny (low viscosity), traveling large distances

These layers of runny, low viscosity lava give shield Volcanoes their characteristic flat, gentle slopes

Shield VolcanoesShield VolcanoesShield VolcanoesShield Volcanoes

100 miles wide

Fluid, basaltic lava releases gases, producingQuiet, non-explosive eruptions

Big Island Hawaii, USABig Island Hawaii, USABig Island Hawaii, USABig Island Hawaii, USA

Big Island, HawaiiBig Island, HawaiiBig Island, HawaiiBig Island, Hawaii

Olympus Mons & Arizona?Olympus Mons & Arizona?Olympus Mons & Arizona?Olympus Mons & Arizona?

Is it steep? Or not steep? Why?Is it steep? Or not steep? Why?Is it steep? Or not steep? Why?Is it steep? Or not steep? Why?

What is a Shield Volcano?

-Shield Volcanoes are ______ volcanoes built up only from layers of ______ (fluid) lava giving them a flat gentle sloping shape

-low viscosity magma releasing gases producing quiet, non-explosive eruptions

-Ex: Big Island of Hawaii, USA

AnswerBanksmall

massivebasalticreleases

low

100 miles wide

Review:Review: 1. Where is a Cinder Cone Volcano?

2. Where is a Composite Volcano

3. Where is a Shield Volcano

4. Which volcano erupts explosively?

5. Which volcano is made of layers of lava, producing flat sides

A

BC

Cinder Cone Composite cone Shield -____ in size

-made of Cinder & ash

-Steep

Ex. Paracutin Mexico

-____ in size

-Made of Ash and thick_____ magma producing ____slopes

- High viscosity magma produces ______ eruptions

Ex. Mt. St. Helens

-____ in size

-made of layers of runny_____magma

-flat, gentle sloping

-Low viscosity magma produces non-explosive ____ eruptions

-Ex. Big island Hawaii

Summarize:Summarize: please draw tableplease draw table

Answer Bank

RhyoliticModerate(2)

violentSmall

basalticExplosive

quietmassive

Shield

Composite Cinder Cone