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Internal Geologic Processes

Internal processes get their energy from the Earth's internal heat.

They are:

Magmatism: generation, rise and solidification of molten rock (magma)

formed by partial melting of the Earth’s interior.  Igneous rocks form by

magmatism.

Metamorphism: change of pre-existing rocks by heat, pressure and

fluids. Metamorphic rocks are the product of this process.

Deformation: change in size, shape and location of rocks and regolith.

http://www.mikeneilson.com/Alabama%20Landscapes%201/Geology/igneous%20rocks.htmhttp://www.mikeneilson.com/Alabama%20Landscapes%201/Geology/met%20rocks.htmhttp://www.mikeneilson.com/Alabama%20Landscapes%201/Geology/met%20rocks.htmhttp://www.mikeneilson.com/Alabama%20Landscapes%201/Geology/igneous%20rocks.htm

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Volcano 

A volcano is an opening, or rupture, in a planet's surface or crust, whichallows hot magma, volcanic ash and gases to escape from below thesurface.

Volcanoes are generally found where tectonic plates are diverging orconverging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, hasexamples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergenttectonic plates coming together.

Magma is molten rock within the Earth's crust. When magma erupts through

the earth's surface it is called lava.

Lava can be thick and slow-moving or thin and fast-moving. Rock also comes

from volcanoes in other forms, including ash (finely powdered rock thatlooks like dark smoke coming from the volcano), cinders (bits of fragmented

lava), and pumice (light-weight rock that is full of air bubbles and is formed

in explosive volcanic eruptions - this type of rock can float on water).

http://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Volcanic_ashhttp://en.wikipedia.org/wiki/Volcanic_ashhttp://en.wikipedia.org/wiki/Rupture_(engineering)http://en.wikipedia.org/wiki/Crust_(geology)http://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Volcanic_ashhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Mid-oceanic_ridgehttp://en.wikipedia.org/wiki/Tectonic_plateshttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Mid-oceanic_ridgehttp://en.wikipedia.org/wiki/Divergent_boundaryhttp://en.wikipedia.org/wiki/Divergent_boundaryhttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Pacific_Ring_of_Firehttp://en.wikipedia.org/wiki/Divergent_boundaryhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Pacific_Ring_of_Firehttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://www.enchantedlearning.com/subjects/volcano/glossary/indexp.shtmlhttp://www.enchantedlearning.com/subjects/volcano/glossary/indexp.shtmlhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Pacific_Ring_of_Firehttp://en.wikipedia.org/wiki/Divergent_boundaryhttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-Atlantic_Ridgehttp://en.wikipedia.org/wiki/Mid-oceanic_ridgehttp://en.wikipedia.org/wiki/Mid-oceanic_ridgehttp://en.wikipedia.org/wiki/Mid-oceanic_ridgehttp://en.wikipedia.org/wiki/Convergent_boundaryhttp://en.wikipedia.org/wiki/Divergent_boundaryhttp://en.wikipedia.org/wiki/Tectonic_plateshttp://en.wikipedia.org/wiki/Volcanic_ashhttp://en.wikipedia.org/wiki/Magmahttp://en.wikipedia.org/wiki/Crust_(geology)http://en.wikipedia.org/wiki/Rupture_(engineering)

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Cross-section through a stratovolcano (vertical scale is exaggerated):

1. Large magma chamber2. Bedrock

3. Conduit (pipe)

4. Base

5. Sill

6. Dike

7. Layers of ash emitted by the volcano8. Flank

9. Layers of lava emitted by the volcano10. Throat

11. Parasitic cone

12. Lava flow

13. Vent

14. Crater

15. Ash cloud

http://en.wikipedia.org/wiki/Stratovolcanohttp://en.wikipedia.org/wiki/Stratovolcano

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Extreme Volcanoes: 

The largest volcano on Earth is Hawaii's Mauna Loa. Mauna Loa is about 6 miles (10

km) tall from the sea floor to its summit (it rises about 4 km above sea level). It alsohas the greatest volume of any volcano, 10,200 cubic miles (42,500 cubic

kilometers). The most active volcano in the continental USA is Mt. St. Helens

(located in western Washington state).

Lava: Magma that has reached the surface of the Earth.

Dike: Tabular body of intrusive magma that cuts across layers of a volcanic structure.

Crater (volcanic): Bowl shaped depression or hollow, usually with steep sides at thesummit of a volcano or on its flanks which is produced by volcanic activity.

Conduit (volcanic): Passageway, more or less cylindrical in shape through whichmagma rises from the magma chamber to the surface during volcanic activity.

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Shield Volcano - A gently-sloping volcano that emits mostlybasaltic lava (very fluid lava) that flows in long-lasting, relatively

gentle eruptions - explosions are minimal. Shield volcanoes can bevery big. An example is Mt. Kilauea (in Hawaii, USA).

Cinder Cone - A cone-shaped volcano whose steep sides areformed by loose, fragmented cinders that fall to the Earth close to the

vent. The lava flows through a single vent that is usually only up to

about 1,000 feet tall. There is usually a bowl-shaped crater at the top.

As the gas-filled lava erupts into the air, the lava fragments into pieces

and forms cinders.

Composite or Strato Volcano - A steep-coned volcano that

explosively emits gases, ash, pumice, and a small amount of stiff, silica lava(called rhyolite). This type of volcano can have eruptions accompanied by lahars

-- deadly mudflows. Most volcanoes on Earth are of this type. Stratovolcanoes

kill more people than any other type of volcanoes - this is because of their

abundance on Earth and their powerful mudflows. Examples are Krakatoa in

Indonesia, Mt. Pinatubo in the Philippines, and Mt. St. Helens in Washington

state, USA.

There are many types of volcanoes:

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Rhyolite Caldera Complex - these are the most explosive volcanoes. They do not

look like common volcanoes -- after an eruption, the result is a caldera (crater)

caused when the area around the vent collapses. Examples are Yellowstone inWyoming, USA and Lake Taupo in New Zealand (which erupted around A.D. 80).

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Lava Dome - A bulbous (rounded) volcano that forms when veryviscous lava barely flows. An example is Mont Pelée in Martinique.

Accumulation of lava in the shape of a steep-sided dome

over an eruptive vent.

Fissure volcano 

Structure composed of the accumulation of volcanic material on

the sides of an eruptive fissure, usually associated with a ridge

or rift situation.

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Compound volcano: Volcanic structure composed of two or

more vents or lava domes or stratovolcanoes, often formed at

different times.

Cinder cone 

Cone build up by the accumulation of loose bits of magma (scoria)

that fall around a vent or crater after being expelled into the air

during moderately explosive activity. If still sufficiently hot they meld

when they fall to the ground.

Caldera 

Large depression produced following an eruption by the

collapse of the roof of a magma chamber. Usually circular or

horseshoe shaped when viewed from above.

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