Volcanoes

By Le Vinh

Contents

• Introduction• Types of volcanoes• Types of volcanic eruptions• Where can you find volcanoes• Why volcanoes erupt• What drives these volcanoes• What does a mountain need to count as a volcano• Diagram of a volcano• Impacts on people when a volcano erupts

Introduction• Volcanoes are a mountain that bursts with lava. Some are active,

some are dormant, and some are extinct• Active volcanoes can erupt any time• Dormant volcanoes have not erupted for many years but an eruption

is still possible• Extinct volcanoes are rather, eroded/worn away by old structures

turning brittle, completely destroyed, or have their magma chambers completely solidified

Types of volcanoes

Complex VolcanoShield Volcano

Stratovolcano

Cinder Cone Lava Dome

Supervolcano

Shield Volcano• Shield volcanoes have a semicircular shape which is basically

formed by viscous lava turning into layers of the gentle sloped volcano. It is known for its shield like structure and low profile

Complex volcano• Complex volcanoes are volcanoes with multiple vents or

explosion craters which overlap each other and pour lava which flows from the cone to the whole volcano

Stratovolcano• Stratovolcanoes are the most common type of volcano than

any other volcano, and the most dangerous volcano type, human evolution has ever witnessed

Cinder cone• Cinder cones are the smallest volcano type in the planet,

standing less than 1,000ft. They blast lava fragments in mid air then toss them down

Lava Dome• Lava domes are inflated piles of molten rock or magma that

rises to the surface and cools, Some are volcanoes with craggy cliffs gently curving and some are hot domes with trapped gasses

Supervolcano• Supervolcanoes are the most terrifying volcanoes on Earth,

They may be outnumbered but their never outmatched

Types of eruptions

HawaiianStrombolian

Plinian Fissure

Hawaiian• Hawiian eruptions are gentle lava flows which goes to the

bottom of the volcano

Fissure• Fissure eruptions erupt in a line form flooding with loads of hot

lava

Plinian

• Plinian eruptions form a mushroom cloud raining with burning rock and thick ash sheets

Strombolian• Strombolian eruptions throw lava bombs hundreds of meters

into the air and spew out sticky lava

Where can you find volcanoes• Volcanoes are found in geothermal zones or uninhabitable

places or near a fault line. They can be found in a hotspot region surrounded by water. They can be part of a volcano group like the Cascade Volcanic Range which stretches out from California to Washington or the Aleutian Volcanic Arc which stretches out from Alaska Peninsula to Kamchatka Peninsula that are merged to form the Pacific Ring Of Fire which surrounds the rim of the Pacific Ocean

Why Volcanoes erupt

• Volcanoes erupt because of two factors. One is that magma that is less dense than the rock surrounding it tries to float to the surface. The magma contains dissolved gases and water from tectonic movement. The volcano pushes the magma towards the surface and when the magma reaches the surface, the dissolved gases and water will now expand into steam and gas causing a huge eruption

• Two is that the magma increases in volume and the magma that’s lighter is pushed towards the bottom of the crater. The lighter magma reaches the rim of the crater and is now lava and overflows

What drives these volcanoes?• Volcanoes are either driven by tectonic activity which swirls magma to

form volcanoes. Then the magma pushes all the way to the Earths surface, bursting lava upwards to form the volcano. There are hundreds of submarine volcanoes which are in a volcanic group like the Hawaiian volcanic ridge or the Mid Atlantic Volcanic Ridge. These submarine volcanoes were able to burst lava upwards but stopped growing before the cone went above sea level.

What does a mountain need to count as a volcano• Volcanoes are not the same as those that are formed in

landmass collisions. Yet they need requirements to count as a volcano

1: It needs to spill lava, molten rock and ash2: Its base needs to be round although fissure vents are line shaped3: It needs to be separate from other mountains although some

mountains have extra vents or close to other mountains 4: It needs to have a magma chamber underneath to support it5: It needs to be constructed out of a type of ash, lava, molten rock

Diagram of a volcano• Here’s my attempt of making a volcano diagram

Magma chamber

Ash Deposit LayersCrater

Extra vent (if possible)

Central Vent

Conduit

Affects on people when a volcano erupts• Volcanoes affect people in either good or bad, The good thing

about the affects of volcanoes is it can produce rich soils for crop growing and farming and the bad thing about its affect is that it can consume houses. Luckily, it is too slow to run over people

Resources

• http://en.wikipedia.org/wiki/Main_Page http://volcano.oregonstate.edu/how-do-volcanoes-affect-people http://www.universetoday.com/77111/why-do-volcanoes-erupt

/

Conclusion

• Thanks for watching this presentation and I hope you enjoyed it