Name     : Istihatul Mufidah
Class     : XII RPL 2
Number     : 12

VOLCANIC ERUPTION

Volcano or volcanoes in general is a term that can be defined as a system of hot fluid channel ( in the form of molten rock or lava ) that extends from a depth of about 10 km below the earth's surface to the earth's surface , including the results of accumulated sediment material issued on when erupted .
When a volcano erupts , magma contained in magma room beneath the volcano erupted out as lava or lava . Other than lava flows , the destruction caused by the volcano through a variety of ways such as the following :

  * The flow of lava .
  * The eruption of the volcano .
  * The flow of mud .
  * Abu .
  * Wildfires .
  * Gas poisonous .
  * Tsunami waves .
  * Earthquakes .

The Causes Volcano

Almost all volcanic activity related to the active seismic zone because it related to plate boundaries . At this plate boundary change in pressure and temperature are very high so as to melt the surrounding material that is the incandescent liquid ( magma ) .

Magma will mengintrusi surrounding rock or soil through cracks close to the surface of the earth .

Formed from volcanic magma , the molten rock deep within the earth . Magma is formed due to the heat in the Earth's interior temperature . At a certain depth , the temperature is very high heat so as to melt the rocks in the earth . When the molten rock , gas then mixed with magma . Most of the magma formed at depths of 60 to 160 km below the earth's surface . Others are formed at depths of 24 to 48 km .
Magma containing gas , gradually rising to the surface because of its mass is lighter than solid rocks around him . When magma rises , the magma melts the rocks nearby , forming a large cabin at a depth of about 3 km from the surface . Cabin magma ( magma chamber) which are part of the warehouse ( reservoir ) where volcanic eruptions originating materials .
Magma containing gas in magma cabin is in a condition under heavy pressure rocks that surround it . This pressure causes the magma erupts or melt conduit ( channel ) on the rocks brittle or cracked . Magma moves out through the channel leading to the surface . When magma close to the surface , the gas content in it regardless . Gas and magma burst together and form a hole called the main hole (central vent ) . Most of the magma and other volcanic material then gush out through this hole . After bursts of stops , crater ( crater ) that resemble bowls typically form on the top of the volcano . While there are major holes in the bottom of the crater .
Formed after the volcano , magma is not all that appears on the next eruption rose up to the surface through the main hole . When magma rises , most likely broken through the wall cracks or branched through smaller channels . Magma through this channel may be out through another hole formed on the side of a mountain , or may remain below the surface .

Impact of Volcanic Eruption
The impact of volcanic eruptions on the environment can be a negative impact and positive . The negative impact of a volcanic eruption can be a danger that can be felt by humans such as hot clouds , pyroclastic fallout , toxic gas that comes out of volcanoes and so forth , while the danger is not immediate after the eruption ended , such as lava rain , destruction of agricultural land , and various diseases caused by pollution . The positive impact of the activity on the environment is a volcanic mineral extractive industry , panas bumi energy , arable land resources , nature areas , and as a water resource .

1 . Negative impact :

    Immediate danger , occurs at the time of eruption ( lava , heat clouds , pyroclastic fallout / bomb , lava eruptions and
    poisonous gas ) .
    Indirect hazard , occurs after the eruption ( lava rain , famine due to damage to land
    agricultural / plantation / fisheries ) , panic , air pollution / water by toxic gas : yellow teeth / loss ,
    endemic goiter , etc.

2 . Positive Impact :

    Minerals : such as stone and sand building materials , housewares , sculptures , and others .
    Minerals : welirang , gypsum , zeolite and also mas ( epithermal gold ) .
    Geothermal energy : electricity , heating , agribusiness
    Hot springs : treatment / health therapy .
    Tourist areas : natural beauty
    Arable land : agriculture and plantations
    Water resources : water , agriculture / animal husbandry , etc.