Volcanoes SEM1 CS 2012

8/3/2019 Volcanoes SEM1 CS 2012

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B Y B O O N A N D D E N Z E L

Volcanic Eruptions



Def inition of Volcanoes

y A volcano is an opening, in a planet's surf ace or crust, which allows hot magma, volcanic ash and gases to escape f rom below the surf ace. Volcanoes are generally f ound

where tectonic plates are div erging or conv erging.



Def inition of Volcanic Eruption

y The sudden occurrence of a violent discharge of steam and volcanic material.





During Volcanic Eruptions

y During a volcanic eruption, lava, tephra, volcanic bombsand various gases are expelled f rom a volcanic v ent orf issure. Se v eral types of volcanic eruptions hav e beendistinguished by volcanologists. These are of ten namedaf ter f amous volcanoes where that type of behavior has

been observ ed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity,

while others may display an entire sequence of types all in

one eruptiv e series.



Common Classif ication of Volcano

y A CTIVE

y EXTINCT

y DORM ANT



Activ e

y Activ e Volcanoes is a volcano that is erupting or isexpected to do so in the near f uture.



Extinct

y Extinct volcanoes are those that scientists considerunlik ely to erupt again, because the volcano nolonger has a lava supply .



Dormant

y It is diff icult to distinguish an extinct volcano f rom adormant one. Volcanoes are of ten considered to be extinct if there are no written records of its activity .

Ne v ertheless, volcanoes may remain dormant f or along period of time.



Cross-section through a stratovolcano :

1.Large magma chamber 2.Bedrock 3.Conduit (pipe) 4.Base 5.Sill 6.Dik e 7.Lay ersof ash emitted by the volcano 8.Flank 9.Lay ers of lava emitted by the volcano10.Throat 11.Parasitic cone 12.Lava f low 13. V ent 14.Crater 15. Ash cloud



Benef its of Volcanoes

y It provide resources f or energy extraction(Geothermal Resources)

y The ash contains many usef ul minerals

(Fertile Soil)y It produce v ery spectacular scenery

(Attract tourist)



Harm of Volcanoes

y Earthquak es and Tsunami that created may destroy island

y Unstoppable Lava can create f ire to e v erything in

their pathy Mudf low with consistency of cement can destroy e v erything in their path





Mount V esuvius

Mount Vesuvius:

The eruption of 79 A D destroy ed the city of Pompeii and

Herculaneum. It is the only volcano on the European

mainland to hav e erupted within the last hundred y ears. Nomuch inf ormation available since it¶s a v ery old eruption.



Mount Tambora

Mount Tambora:

It¶s erupted in 1815, lef t nearly 71,000 people dead. It was the largest eruption in the history of

volcano. The eruption created a volcanic winterand turn the y ear without summer.





MoralHazard f rom Eruption

y As a natural disaster, may happen at any time. W e only can predict when it will be happen, e v en thoughthe measure time cannot be 100% accurate. The

technology help us to avoid more lost of liv es and belongings. On the other hand w e hav e to see the positiv e of the nature giv e, it come as a circle.



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Volcanoes SEM1 CS 2012

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