Volcano Vocabulary

  1. volcano
    A weak spot in the crust where magma has come to the surface.
  2. magma
    The molten mixture of rock-forming substances, gases, and water from the mantle.
  3. lava
    Liquid magma that reaches the surface; also the rock formed when liquid lava hardens.
  4. Ring of Fire
    A major belt of volcanoes that rims the Pacific Ocean.
  5. island arc
    A string of islands formed by the volcanoes along a deep-ocean trench.
  6. hot spot
    An area where magma from deep within the mantle melts through the crust above it.
  7. element
    A substance that cannot be broken down into other substances.
  8. compound
    A substance in which two or more elements are chemically joined.
  9. physical property
    Any characteristic of a substance that can be observed or measured without changing the composition of the substance.
  10. chemical property
    Any property of a substance that produces a change in the composition of matter.
  11. viscosity
    The resistance of a liquid to flowing.
  12. silica
    A material found in magma that is formed from the elements oxygen and silicon.
  13. pahoehoe
    A hot, fast-moving type of lava that hardens to form smooth, ropelike coils.
  14. aa
    A slow-moving type of lava that hardens to form rough chunks; cooler than pahoehoe.
  15. magma chamber
    The pocket beneath a volcano where magma collects.
  16. pipe
    A long tube through which magma moves from the magma chamber to Earth’s surface.
  17. vent
    The opening through which molten rock and gas leave a volcano.
  18. lava flow
    The area covered by lava as it pours out of a volcano’s vent.
  19. crater
    A bowl-shaped area that forms around a volcano’s central opening.
  20. pyroclastic flow
    The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption.
  21. dormant
    A volcano that is not currently active, but may become active in the future.
  22. extinct
    A volcano that is no longer active and is unlikely to erupt again.
  23. shield volcano
    A wide, gently sloping mountain made of layers of lava and formed by quiet eruptions.
  24. cinder cone
    A steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano’s opening.
  25. composite volcano
    A tall cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials. aka stratovolcano
  26. caldera
    The large hole at the top of a volcano formed when the roof of a volcano’s magma chamber collapses.
  27. volcanic neck
    A deposit of hardened magma in a volcano’s pipe.
  28. dike
    A slab of volcanic rock formed when magma forces itself across rock layers.
  29. sill
    A slab of volcanic rock formed when magma squeezes between layers of rock.
  30. batholith
    A mass of rock formed when a large body of magma cools inside the crust.
  31. geothermal activity
    The heating of underground water by magma.
  32. geyser
    A fountain of water and steam that builds up pressure underground and erupts at regular intervals.
Card Set
Volcano Vocabulary
Volcano Vocabulary