Signs of an Eruption
 Signs of an eruption are that magma is collecting in a magma chamber.  Also there would be heat and gasses coming out of a volcano.
 
 

Causes for eruptions
    Causes for eruptions: are heat and pressure making magma then since it is lighter than rock it rises to the magma chamger then it becomes what is called an eruption.
 

 
  The Hazards of volcanoes
The Hazards of volcanoes are that if lava touches you, you will disintegrate or in other words burn very fastly. Volcanoes also have gasses that are poisonis and if you inhale to much it can be dangerouse.  Volcanoes are also dangerouse because the can make big explosions of rock and sent it flying far without warning and wipe out everything.