AN OPENING IN THE EARTH'S CRUST WHICH MELTED MATERIAL ERUPTS

ERUPTS CONSTANTLY

ERUPTS ON A REGULAR BASIS

HASN'T ERUPTED IN A WHILE BUT COULD AT ANY TIME

NOT ERUPTED IN RECORDED TIME

FORMED BY EXPLOSIVE ERUPTIONS

FORMED BY ALTERNATING LAYERS OF ROCK AND LAVA

LAVA FLOWS QUICKLY OVER A LARGE AREA

HUGE CRATER FORMED WHEN SIDES OF VOLCANO COLLAPSE

ERUPTION OF LAVA SO THICK IT BULGES UP TO SURFACE