a weak spot in the crust where magma has come to the surface
a molten mixture of rock-forming substances, gases, and water from the mantle
Liquid magma that reaches the surface; also the rock formed when liquid lava hardens.
Ring of Fire
a major belt of volcanoes that rims the Pacific Ocean
A string of islands formed by the volcanoes along a deep ocean trench
an area where magma from deep within the mantle melts through the crust above it
a substance in which all the atoms are the same that cannot be broken down into other substances
a substance in which two or more elements are chemically joined
A characteristic of a substance that can be observed without changing it into another substance.
any property of a substance that produces a change in the composition of matter
A liquid's resistance to flowing
a material found in magma that is formed from the elements oxygen and silicon
a hot, fast-moving type of lava that hardens to form smooth, ropelike coils
a slow-moving type of lava that hardens to form rough chunks; cooler that pahoehoe
the pocket beneath a volcano where magma collects
a long tube through which magma moves from the magma chamber to Earth's surface
The opening through which molten rock and gas leave a volcano
the area covered by lava as it pours out of a volcano's vent
a bowl-shaped area that forms around a volcano's central opening
The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption
A volcano that is not currently active, but may become active in the future.
a volcano that is no longer active and is unlikely to erupt again
a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions
a steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening
a tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials
The large hole at the top of a volcano formed when the roof of a volcano's magma chamber collapses.
a deposit of hardened magma in a volcano's pipe
a slab of volcanic rock formed when magma forces itself across rock layers
a slab of volcanic rock formed when magma squeezes between layers of rock
A mass of rock formed when a large body of magma cools inside the crust
the heating of underground water by magma
A fountain of water and steam that erupts from the ground