VOLCANOES
Ever try to hold back a sneeze...or a burp?You feel the pressure building up and you just can't stop it.It's not your fault.It's nature's way.
An active volcano is like a giant sneeze.Melted rock (magma) mixed with gases is forced up from miles underground.As pressure builds,it erupts through the thin crust that separates earth's insides from its outside.Like a runny nose,a small opening may ooze a trickle of hot melted rock.Just as some sneezes are polite little a-choos,sometimes this molten rock relieves its pressure gradually,in small pops.And just as some sneezes are tissue-shredders,sometimes the hot stuff blasts its way out with a force that takes off the top of the mountain.See for yourself what's inside a volcano and what comes out.
volcanos can de divided mainly into three forms or in other word volcano status are DORMANT, ACTIVE, EXTINCT . DORMANT :Has erupted in the past and may erupt again,but is not now erupting. ACTIVE :Currently erupting or dormant. EXTINCT :Has not erupted for a very long period of time. The various components of a volcanos are ERUPTION CLOUD,CONE,LAVA,MAGMA,PYROCLASTIC,CRATER,CENTRAL VENT,SIDE VENT,FEEDER TUBE,CRUST,MANTLE,CORE.
ERUPTION CLOUD-Cloud coming from a volcano that contains tephra (ash) and gas.
CONE-Mountain in a cone shape that is built up layer by layer through many eruptions.
LAVA-Magma that has erupted from a volcano.
MAGMA-Hot liquid rock and gases in Earth,s mantle or crust;the magma chamber is a pool that feeds a volcano.
PYROCLASTIC-Rock fragments blasted out of an exploding volcano.They can form fast-moving flows full of hot gas that are much more quickly destructive than molten lava flows.
CRATER-Top of central vent that has widened over a number of eruptions.
CENTRAL VENT-Hole at the top of a volcano through which magma erupts.
SIDE VENT-Another hole,or crack,in the Earth,s surface that connects with the feeder tube and through which magma can also erupt.
FEEDER TUBE-Long passage in the earth that transports magma to the surface.
The poisonous gases are :
1. Carbon dioxide(CO2).
2. Hydrogen fluoride(HF).
3. Hydrogen sulfide(H2S).
4. Sulfur dioxide(SO2).
5. Hydrogen Chloride(HCL).
The layers of the Earths are crust,Mantle,Core. Crust is the topmost layer of the earth. Mantle begin 3 to 25 miles(5 to 40 km) beneath Earth's surface. And Core begins 1,800 miles(2,900 km) beneath Earth,s surface and extends to the center. Why magma like to be so hot?,Except for all the pressure. Magma is sitting under miles of crust,and it weights billions of tons. Sometimes magma can't take it.So it escape to the surface through a volcano.The instant magma hit the surface,magma turn into lava.They are the same hot stuff : melted rock with a bunch of gases mixed in it. They are two thousand degrees Fahrenheit,or eleven hundred degrees celsius. Magma is everywhere in underground,except for one thin solid pat on the top,the earth mantle is all about magma. We all are sitting on magma right now.but they are at least twenty miles down.
There are Five Hundred Active Volcanoes in the world.About sixty of them blow up every year.volcanoes don,t happen every where,they need the right place in the Earth,s crust.The right place is where the crust is so thin it's cracked,or it's got a hole in it.That's when magma make a move.Either I blast out or spill out,depending on magma type.The magmas are not all same.They have got in Four different types: Andesite,Basalt,Dacite and Rhyolite.Magmas basalt type is thin.It's weak.It makes bubbles and sprays and pretty fountains of lava and stuff when it erupts.Magmas other type is thicker,strong,powerful.They make the best blast,especially Rhyolite,which is the thickest of all.If magmas are thick.They get stubborn.Magma block up the magma chamber.the gases all crowd together below and around magma.They want to get through,and magma won't give .then they bunch up in the pockets and sit there fuming and expanding until finally_BLAMMO!This time it's like you shake and shake your cola and then rip off the top and spray it all over the place!.
Stratovolcano. That's the kind of volcano made by the biggest blast and the thicker kinds of magma. Mount st.Helens is a stratovolcano. So is Mount Vesuvius in Italy,and Mount peel in Martinique,and tons of other big guys. They're tall and steep,with sides all built up by lava and rock. Another name for them is Composite. If thicker magma makes stratovolcanoes,what do volcanoes made by basaltic magma-the thinner kind looks like a kind of round and wide. They are called shield volcanoes. Hawaii is full of them. In fact,the Hawaiian Island are shield volcanoes.
The thickness of a liquid such as magma is called it's viscosity,or resistance to flow. The viscosity of magma depends on its temperature,water content,and the amount of a mineral called silica in in. The thicker the magma,the more silica in it.
Ever try to hold back a sneeze...or a burp?You feel the pressure building up and you just can't stop it.It's not your fault.It's nature's way.
An active volcano is like a giant sneeze.Melted rock (magma) mixed with gases is forced up from miles underground.As pressure builds,it erupts through the thin crust that separates earth's insides from its outside.Like a runny nose,a small opening may ooze a trickle of hot melted rock.Just as some sneezes are polite little a-choos,sometimes this molten rock relieves its pressure gradually,in small pops.And just as some sneezes are tissue-shredders,sometimes the hot stuff blasts its way out with a force that takes off the top of the mountain.See for yourself what's inside a volcano and what comes out.
volcanos can de divided mainly into three forms or in other word volcano status are DORMANT, ACTIVE, EXTINCT . DORMANT :Has erupted in the past and may erupt again,but is not now erupting. ACTIVE :Currently erupting or dormant. EXTINCT :Has not erupted for a very long period of time. The various components of a volcanos are ERUPTION CLOUD,CONE,LAVA,MAGMA,PYROCLASTIC,CRATER,CENTRAL VENT,SIDE VENT,FEEDER TUBE,CRUST,MANTLE,CORE.
ERUPTION CLOUD-Cloud coming from a volcano that contains tephra (ash) and gas.
CONE-Mountain in a cone shape that is built up layer by layer through many eruptions.
LAVA-Magma that has erupted from a volcano.
MAGMA-Hot liquid rock and gases in Earth,s mantle or crust;the magma chamber is a pool that feeds a volcano.
PYROCLASTIC-Rock fragments blasted out of an exploding volcano.They can form fast-moving flows full of hot gas that are much more quickly destructive than molten lava flows.
CRATER-Top of central vent that has widened over a number of eruptions.
CENTRAL VENT-Hole at the top of a volcano through which magma erupts.
SIDE VENT-Another hole,or crack,in the Earth,s surface that connects with the feeder tube and through which magma can also erupt.
FEEDER TUBE-Long passage in the earth that transports magma to the surface.
The poisonous gases are :
1. Carbon dioxide(CO2).
2. Hydrogen fluoride(HF).
3. Hydrogen sulfide(H2S).
4. Sulfur dioxide(SO2).
5. Hydrogen Chloride(HCL).
The layers of the Earths are crust,Mantle,Core. Crust is the topmost layer of the earth. Mantle begin 3 to 25 miles(5 to 40 km) beneath Earth's surface. And Core begins 1,800 miles(2,900 km) beneath Earth,s surface and extends to the center. Why magma like to be so hot?,Except for all the pressure. Magma is sitting under miles of crust,and it weights billions of tons. Sometimes magma can't take it.So it escape to the surface through a volcano.The instant magma hit the surface,magma turn into lava.They are the same hot stuff : melted rock with a bunch of gases mixed in it. They are two thousand degrees Fahrenheit,or eleven hundred degrees celsius. Magma is everywhere in underground,except for one thin solid pat on the top,the earth mantle is all about magma. We all are sitting on magma right now.but they are at least twenty miles down.
There are Five Hundred Active Volcanoes in the world.About sixty of them blow up every year.volcanoes don,t happen every where,they need the right place in the Earth,s crust.The right place is where the crust is so thin it's cracked,or it's got a hole in it.That's when magma make a move.Either I blast out or spill out,depending on magma type.The magmas are not all same.They have got in Four different types: Andesite,Basalt,Dacite and Rhyolite.Magmas basalt type is thin.It's weak.It makes bubbles and sprays and pretty fountains of lava and stuff when it erupts.Magmas other type is thicker,strong,powerful.They make the best blast,especially Rhyolite,which is the thickest of all.If magmas are thick.They get stubborn.Magma block up the magma chamber.the gases all crowd together below and around magma.They want to get through,and magma won't give .then they bunch up in the pockets and sit there fuming and expanding until finally_BLAMMO!This time it's like you shake and shake your cola and then rip off the top and spray it all over the place!.
Stratovolcano. That's the kind of volcano made by the biggest blast and the thicker kinds of magma. Mount st.Helens is a stratovolcano. So is Mount Vesuvius in Italy,and Mount peel in Martinique,and tons of other big guys. They're tall and steep,with sides all built up by lava and rock. Another name for them is Composite. If thicker magma makes stratovolcanoes,what do volcanoes made by basaltic magma-the thinner kind looks like a kind of round and wide. They are called shield volcanoes. Hawaii is full of them. In fact,the Hawaiian Island are shield volcanoes.
The thickness of a liquid such as magma is called it's viscosity,or resistance to flow. The viscosity of magma depends on its temperature,water content,and the amount of a mineral called silica in in. The thicker the magma,the more silica in it.
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