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Volcanoes
By: Mr. Anderson
What is a volcano?A volcano is a mountain that opens downward to a pool of molten rock below the surface of the earth.
When pressure builds up, an eruption occurs!!!
What is an Eruption?An eruption is when molten rock, gases, steam, and lava are ejected out of a volcano.
These eruptions can cause:Earthquakes
Mudslides
Flash floods and more!
What is lava? What is Magma? What’s the difference?Lava- Lava is liquid rock that flows out of the volcano. It glows red hot and changes to white as it goes
Magma- Liquid rock inside the volcano
Magma is inside the volcano and Lava is outside the volcano!
How are Volcanoes formed?1.Magma from the Earth’s mantle is pushed up to the surface
2.At the surface it erupts and turns into lava
3. Lava flows out and ash is put into the air
4. The more a volcano erupts, the bigger it gets!!
The lava cools and continues to form layers on top of itself. SUPER NEAT :)
3 stages of VolcanoesDormant
Extinct
Active
Active VolcanoAn active volcano is one which has recently erupted and there is a possibility that it may erupt soon
Dormant VolcanoA dormant volcano is one which has not erupted in a long time but there is a possibility it can erupt in the future.
Extinct Volcano
An extinct volcano is one which has erupted thousands of years ago and there’s no possibility of eruption.
Why do Volcanoes Erupt?The Earth’s crust is made up of huge slabs or plates and they fit together like a puzzle
When these plates try to move, they cause friction.
This friction causes earthquakes and volcanic eruptions near the edges or fault areas!!!
What is the name of this theory?????
What is plate Tectonics?A theory that the continents drift or move from place to place
They: break apart, collide, and grind against each other.
4 types of VolcanoesCinder Cones
Composite Shield
Lava Volcanoes
Cinder ConesCircular or oval cones
small/single vent in the crustFragments cool and fall around the vent
Composite VolcanoesSteep-sided
Many layers of volcanic rockMade from lava, ash, and rock debris
Shield Volcano
shaped like a bowl or shield in the middlelong gentle slopes made by balastic flow
Lava Volcanoes
The domes are made when lava erupting is to thicksteep sided mounds of lava pile up near the vent
Pyroclastic FlowsA fast
movement of fluidized
mixture that contains gas and rocks.
Ring of Fire
String of volcanoesand sites of seismic activities
This area has lots of Earthquakes and Volcanic Eruptions
Around edges of Pacific Ocean