A weak spot in the crust where magma has come to the surface.
Liquid magma that reaches the suface; also, the rock formed when liquid lava hardens.
The molten mixture of rock-forming substances, gases, and water from the mantle.
A string of islands formed by the volcanos along a deep-ocean trench
An area where magam from deep within the mantle melts through the crust above it.
A material found in magam that is formed from the elements oxygen and silicon.
An explosive volcanic eruption of ash, cinders, bombs, and gases.
A volcano that is not currently active, but that may become active in the future.
A volcano that is no longer active and is unlikly to erupt again.
A wide, gently sloping mountain made of layers of lava; formed by quiet eruptions.
cinder cone volcano
A steep, cone shaped hill or small mountain made of volcanic ash, cinders, and bombs.
A tall, cone shaped mountain in which layers of lava and ash alternate
The large hole at the top of a volcano formed when the roof of a magam chamber collapses.