REVOLUTIONS-INDUSTRIAL AND INFORMATION

VOLCANOES     are  natural    phenomenon   that  occur  every where  but  some  places  are    more  prone  than   others.The   molten   rock   and  gas   in   the   mantle  called  magma  pushes  its  way  up words   and  pours  to  the surface through  cracks  in  the  crust.This  is  Volcano.There  are  different  types  of  Volcanoes.some  are  explosive   ,others   are  not,and  all  erupt    as  spectacularly   as   we  see..Some   eruptions   takes  place   unexpectedly ,but  others  can  be  predicted ,  which  is  very   important   for  the   people  living  near   a  Volcano.
DIFFERENT  TYPES   OF  VOLCANOES.-IT  depends   on  the   matter   coming  out  of  the&nbsp ;  Earth's core.if   the  magma  is   more  than  1000Centrigrade  ,it  is  dark  ,thin  and  flows  quietly .sides  of  such  Volcanoes  have   gradual   slopes.If   magma  is   cold  ,then  it   erupts in   explosions .The  volcanic   cone  is  steeper .Because   of  the  heat  in  Earth's  core,geysers,solfatars, and  hot  water  sources   are  found near  the   volcano.
Volcanoes    become  dangerous   when  it  cause    damage   to  human  life  .If  a  Volcano  starts    spewing   hot   gases  and  gas   in  a  densely   populated   area   many  lives  are at  risk.Explosive  volcanic  eruptions   discharge   huge   amount  of   dust  and  ash  ,often  burying    near  by  areas .Thin  dark   magma   can  flow  at  a   speed   of  up  to  100km/h  making  it  impossible   to  escape  .
Volcanic  eruptions   can  also  have  far    reaching    consequences .Some  times    volcanic  ash  can  reached  up  to   a  height  of  80  km  ,which  for  some  time    darkened  the  sky  world  wide,as happened  in  the  case  of Krakatau volcano    erupted  in  1883  ,in  Indonesia.  
VOLCANOES   are  found   primarily,at  the  border   of  the  plates,where  the  oceanic  Earth's  crust  submerges below  another  plate ,melts  in  the  depth   and  magma  rises.This  is  generally    the  case all  around  the  pacific  ocean.Here  the  cocos    and N Nazca   plates  submerge   below  the  middle   and  south  America  ,and  the  pacific  plate  submerge   below  the  small   plates  in  the   southeast   Asia.Volcanoes  are  found    in  areas   ranging   from   Italy   to  Turkey   and   Iran  up  to   the  Indonesian   Islands.Very    rarely  ,volcanoes  are   found  in  the  middle   of   a  plate..These  occur  only  in 'hot  spots' which  are  areas   of  high   volcanic  activity.,such  as  the  Hawaiian  Islands.
PREDICTION   OF  VOLCANOES.-It  is  very  difficult   to  predict  volcanic   eruption  .But  we   can  save  lives .Early  tremors  and  Earthquake   are   often  signs  of a  volcanic  eruption-gases  are   emitted   and  the  volcano   expands  by  a  centimetres   to  a  metre  .The  vulcanologist    carefully  observes  these  signs .In  1991  ,before  the  eruption  of   Pinatubo  in   Philippines  ,these  signs  were  interpreted      correctly    and  over  10,000  people  were  moved  to  safer  places.Often  ,people  do  not  believe    the  scientist's  prediction .In  1985, before  the  eruption  of  Nevada  Del  Ritz  in  Columbia ,though  the  danger   was  predicted     very  early,the  authorities   did  not  react   quickly and  as  a  result  25,000  people died.
VOLCANOES 

VOLCANOES are natural phenomenon that occur every where but some places are more prone than others.The molten rock and gas in the mantle called magma pushes its way up words and pours to the surface through cracks in the crust.This is Volcano.There are different types of Volcanoes.some are explosive ,others are not,and all erupt as spectacularly as we see..Some eruptions takes place unexpectedly ,but others can be predicted , which is very important for the people living near a Volcano. DIFFERENT TYPES OF VOLCANOES.-IT depends on the matter coming out of the&nbsp ; Earth's core.if the magma is more than 1000Centrigrade ,it is dark ,thin and flows quietly .sides of such Volcanoes have gradual slopes.If magma is cold ,then it erupts in explosions .The volcanic cone is steeper .Because of the heat in Earth's core,geysers,solfatars, and hot water sources are found near the volcano. Volcanoes become dangerous when it cause damage to human life .If a Volcano starts spewing hot gases and gas in a densely populated area many lives are at risk.Explosive volcanic eruptions discharge huge amount of dust and ash ,often burying near by areas .Thin dark magma can flow at a speed of up to 100km/h making it impossible to escape . Volcanic eruptions can also have far reaching consequences .Some times volcanic ash can reached up to a height of 80 km ,which for some time darkened the sky world wide,as happened in the case of Krakatau volcano erupted in 1883 ,in Indonesia. VOLCANOES are found primarily,at the border of the plates,where the oceanic Earth's crust submerges below another plate ,melts in the depth and magma rises.This is generally the case all around the pacific ocean.Here the cocos and N Nazca plates submerge below the middle and south America ,and the pacific plate submerge below the small plates in the southeast Asia.Volcanoes are found in areas ranging from Italy to Turkey and Iran up to the Indonesian Islands.Very rarely ,volcanoes are found in the middle of a plate..These occur only in 'hot spots' which are areas of high volcanic activity.,such as the Hawaiian Islands. PREDICTION OF VOLCANOES.-It is very difficult to predict volcanic eruption .But we can save lives .Early tremors and Earthquake are often signs of a volcanic eruption-gases are emitted and the volcano expands by a centimetres to a metre .The vulcanologist carefully observes these signs .In 1991 ,before the eruption of Pinatubo in Philippines ,these signs were interpreted correctly and over 10,000 people were moved to safer places.Often ,people do not believe the scientist's prediction .In 1985, before the eruption of Nevada Del Ritz in Columbia ,though the danger was predicted very early,the authorities did not react quickly and as a result 25,000 people died. VOLCANOES