Volcanoes

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Volcanoes
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What is a Volcano?
Hot Lava

• Mountains that
• erupt lava

Cold Rock
ACTIVE
Z
Z
z
DORMANT
EXTINCT
Hawaii
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How Hot is Lava?

• Measuring the temperature

1160C
Heat suit
USGS photo by R.L. Christiansen Jan.9, 1973
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Inside and below a Volcano
vent
cone
magma chamber
conduit
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What is lava and magma?
melt
bubbles
crystals
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Where does magma come from?

• A look inside the Earth

Mantle
Solid that flows
Runny
Outer Core
Crust
Solid
Inner Core
Solid
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Where does magmacome from?

• A look at the mantle and crust

Crust
Mantle
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Why do volcanoes erupt?
Hot air
Cold air
Ocean
Cold Crust
Hot Melt
Hot Mantle
Cooler Mantle
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How do they erupt?

• EXPLOSIVE

• EFFUSIVE

magma
magma
Sticky Lots of Bubbles
Runny Not many bubbles
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How do they erupt?

• EFFUSIVE

• EXPLOSIVE

Sticky Lots of Bubbles!
Runny Not many Bubbles
Hawaii
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Explosive Volcanoes
Montserrat
Montserrat
Ash Fall
Pyroclastic Flow
Pyroclastic Flow
Courtesy of www.swisseduc.ch
Pyroclastic Flow
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Effusive Volcanoes

• aa

• Pahoehoe

Aa flows
Pahoehoe flows
Rough Lots of pieces
Smooth or Ropy
Courtesy of A. Rust
Courtesy of A. Rust
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Where can we find volcanoes?

• World map of volcanoes erupted within the past
  10,000 years

Courtesy of Smithsonian Institution Global
Volcanism Program
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Activity
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Activity

• Making a Volcanic Eruption
• You will need
• 2 litre bottle of soda or cola
• 1 roll of mints

What helps make explosive eruptions?
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Activity

• Bubbles

USGS/Hawaiian Volcano Observatory Photo by J.D.
Griggs
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Volcanic Hazards

• Danger to People, Places and Things

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Volcanic Hazards

• Explosive Pyroclastic Flow
• Flows sweeping away buildings

Bent bars of a broken house. Which way did the
flow go?
Fast flowing rocks!
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Volcanic Hazards

• Explosive Burial
• Flows burying buildings

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Volcanic Hazards

• Explosive Burns
• Hot flows burning trees and buildings.

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Volcanic Hazards

• Explosive Lahars
• Fast flowing water and rock

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Volcanic Hazards

• Explosive Ash Fall
• Ash falling from eruption

USGS/Cascades Volcano Observatory Photo by David
Wieprecht
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Volcanic Hazards

• Effusive Lava Flows

Pahoehoe flows
Courtesy of Swisseduc.ch
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Volcanic Hazards

• Noxious Gas
• Magma loses bubbles
• Gas leaks into the air

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Volcanic Hazards

• Earthquakes
• Magma pushes on crust
• Shakes and breaks buildings and roads

Japan
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Volcanoes

• Examples from Past and Present

Courtesy of www.swisseduc.ch
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Pompeii

• Vesuvius, Italy 79AD
• Explosive
• Ash and flows covered Pompeii

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Pompeii

• Excavations

cc. of Crew Creative
cc. Crew Creative
Gladiators Barracks
Pompeii
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Pompeii

• Plaster casts of bodies

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Pompeii

• Vesuvius today

Naples
Vesuvius
Bay of Naples
Pompeii
Courtesy of www.swisseduc.ch
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Pelée

• Mt. Pelée,
• Martinique - 1902

Before
After
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Pelée

• 29,000 people died
• 2 survived

Why?
Photo by Angelo Heilprin
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Heimaey

• Vestmannaeyjer,
• Iceland - 1973

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Heimaey

• Lava flows caught people by surprise

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Heimaey

• Spraying seawater to slow or stop lava flows

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Question
?

• What can we do to help people who live near
  active volcanoes?

Mt. St. Helens
1. Look and Learn
2. Watch Active Volcanoes
3. Escape Plans
4. Find out why people live near volcanoes
5. Teach
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Volcano monitoring
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Volcano Monitoring

• Volcano Observatories on Active Volcanoes

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Volcano Monitoring

• Ground bulging or popping up

tiltmeter
magma
tiltmeter
tiltmeter
magma
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Volcano Monitoring

• Earthquakes

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Volcano Monitoring

• Gas or Bubbles

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Brain Challenge

• Questions about Volcanoes

Photo Tom Pfeiffer / www.volcanodiscovery.com
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Brain Challenge

• Questions

V____
e n t
What is a volcano? Mountains that erupt
.
l a v a
Cone
Lava is very hot cold
Conduit
A dormant volcano is awake asleep
________ chamber
M a g m a
What is lava and magma? m bubbles
crystals
e l t
Why do volcanoes erupt? Hot magma wants to go
up down
How do volcanoes erupt? Two types e
and effusive
.
x p l o s i v e
What helps make explosive volcanoes erupt?
.
b u b b l e s
Explosive volcanoes erupt a lot of
into the air.
a s h
Do effusive volcanoes have runny or sticky lava?
.
r u n n y
Can lava burn trees and houses?
yes
Can you outrun a pyroclastic flow?
no
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Danger on the Island

• Where can people live safely on the island?

C Active
B Extinct
A Extinct
N
3km
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Montserrat

• Real-Life Scenario

Pyroclastic Flow
Courtesy of www.swisseduc.ch
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The End