VOLCANOES

 

       A volcano is a mountain. It has an opening or "vent" into the Earth's interior. When pressure occurs, the volcano erupts. Magma shoots through the opening and spills over. When magma overflows it is called lava.                                    

      They are formed when magma flows from the Earth's upper mantle up into the Earth's surface. Gas, pieces of rock, dust and ash come out of a volcano along with magma when it erupts. Lava also can be thick or thin. 

       

      An eruption can trigger many things such as tsunamis, flash floods, earthquakes, mudflows, and rockflows.

        

      Most active volcanoes in the world lie in a huge belt around the Pacific Ocean. It is called the "Ring of fire" Some volcanos, are even hidden under the ocean.

       

     After a volcano erupts thousands of times it is said to be dormant, or in other words "sleeping." Some of them may become active again.