ash cloud - an ash cloud is the cloud of ash that forms in the air after some volcanic eruptions.
conduit - a conduit is a passage through which magma (molten rock) flows in a volcano.
crust - the crust is Earth's outermost, rocky layer.
lava - lava is molten rock; it usually comes out of erupting volcanoes.
magma chamber - a magma chamber contains magma (molten rock) deep within the Earth's crust.
side vent - a side vent is a vent in the side of a volcano.
vent - a vent is an opening in the Earth's surface through which volcanic materials erupt.