the large hole at the top of a volcano formed when the roof of a volcano’s magma chamber collapses.

a weak spot in the crust where magma has come to the surface.

said of a volcano that is unlikely to erupt again.

wide, gently sloping mountain made of layers of lava and formed by quiet eruptions.

a type of hot spring that builds up pressure underground and erupts at regular intervals as a fountain of water and steam.

said of a volcano that does not show signs of erupting in the near future.

a steep, cone-shaped hill or mountain made of volcanic ash, cinders, and bombs piled up around a volcano’s opening.

a major belt of volcanoes that rims the Pacific Ocean.

a hot, fast-moving type of lava that hardens to form smooth, ropelike coils.

a tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials.

a pool formed by groundwater that has risen to the surface after being heated by a nearby body of magma.

said of a volcano that is erupting or has shown signs of erupting in the near future.

the opening through which molten rock and gas leave a volcano.

a slow-moving type of lava that hardens to form rough chunks.

a bowl-shaped area that forms around a volcano’s central opening.

the pocket beneath a volcano where magma collects.

a mass of rock formed when a large body of magma cooled inside the crust.

an area where magma from deep within the mantle melts through the crust above it. (Stationary Weakness)