Transcript Volcanoes Powerpoint

• Mountains
that
erupt lava
Lava
ACTIVE
Z
Zz
Rock
DORMANT
EXTINCT
Hawaii
• Measuring the temperature
Heat suit
USGS photo by R.L. Christiansen Jan.9, 1973
vent
cone
conduit
magma
chamber
• A look inside the Earth
Mantle
Outer Core
Inner
Solid
Core
Solid
Crust
Crust
• A look at the
mantle and crust
Mantle
Cold air
Ocean
Hot Melt
Hot Mantle
Cooler
Mantle
• EXPLOSIVE
magma
Sticky
Lots of Bubbles
• EFFUSIVE
magma
Runny
Not many bubbles
Hawaii
Courtesy of www.swisseduc.ch
• ’a’a
• Pahoehoe
Rough
Lots of pieces
Smooth
or Ropy
Courtesy of A. Rust
Courtesy of A. Rust
• World map of volcanoes erupted within the past 10,000 years
Courtesy of Smithsonian Institution Global Volcanism Program
• Making a Volcanic Eruption
• You will need:
• 2 litre bottle of soda or cola
• 1 roll of mints
What helps make explosive eruptions?
• Bubbles
USGS/Hawaiian Volcano Observatory
Photo by J.D. Griggs
Danger to People, Places and Things
• Explosive: Pyroclastic Flow
• Flows sweeping away buildings
Fast flowing rocks!
Bent bars of a broken house.
Which way did the flow go?
• Explosive: Burial
• Flows burying buildings
• Explosive: Burns
• Hot flows burning trees and buildings.
• Explosive: Lahars
• Fast flowing water and rock
• Explosive: Ash Fall
• Ash falling from eruption
USGS/Cascades Volcano Observatory
Photo by David Wieprecht
• Effusive: Lava Flows
Courtesy of Swisseduc.ch
• Noxious Gas
• Magma loses bubbles
• Gas leaks into the air
• Earthquakes
• Magma pushes on crust
• Shakes and breaks buildings and roads
Examples from Past and Present
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• Vesuvius, Italy – 79AD
• Explosive
• Ash and flows covered Pompeii
• Excavations
cc. of Crew Creative
cc. Crew Creative
• Plaster casts of bodies
• Vesuvius today
Naples
• Mt. Pelée,
Martinique - 1902
• 29,000 people died
• 2 survived
Photo by Angelo Heilprin
• Vestmannaeyjer,
Iceland - 1973
• Lava flows caught people by surprise
• Spraying seawater to slow or stop lava flows
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
• Volcano Observatories on Active Volcanoes
• Ground bulging or
popping up
tiltmeter
magma
magma
• Earthquakes
• Gas or Bubbles
• Questions
V____
ent
What is a volcano? Mountains that erupt l a v a .
Lava is very:
hot
A dormant volcano is:
Cone
cold
awake
Conduit
M
________
a g m a chamber
asleep
What is lava and magma? m e l t + bubbles + crystals
Why do volcanoes erupt? Hot magma wants to go:
up
How do volcanoes erupt? Two types: e x p l o s i v e
down
and effusive
What helps make explosive volcanoes erupt? b u b b l e s .
Explosive volcanoes erupt a lot of a s h into the air.
Do effusive volcanoes have runny or sticky lava?
Can lava burn trees and houses? yes
Can you outrun a pyroclastic flow?
no
runny .
.
• Where can people live safely on the island?
C
Active
B
Extinct
A
Extinct
N
3km
• Real-Life Scenario
Courtesy of www.swisseduc.ch