A volcano can cause many hazard's for people. Lava is the most destutive thing for people and aminal. Ash falling through the air can cover up a city, and even states. Smoke can cause promblems for people, caron dixide can kill people. This is hazard's
 
 

                           Cause's of erouptions
 

             A volacno will  erupt when so much pressure is inside the volacno. After the erouption magma starts to come out of the volcano. And anouther way a volcano will erupt is when the magma is to great and all the chambers are full. After the magma comes out it and the magma is thick the gas can not get out easy. This is my summery on causes of erouption.
 

           Sign's of erouption

       Sign's of erouption are if smoke or earthquake's happen. Earthauake's  happen around the volcano it might be an erouption for the volcano. If you see smoke it might be an erouption. Some volcano's will send out smoke but it will not eroupt. This is my summery on sign's of erouption.