Volcanoes form when magma rises from below the Earth's surface and erupts through openings called vents. As magma accumulates at the vent it builds up a mountain-like structure called a volcano. There are three main types of volcanoes defined by their shape and eruption characteristics: shield volcanoes which have broad bases and gentle slopes formed by fluid basaltic lava flows; cinder cone volcanoes which are steep-sided with a small base formed from explosive eruptions of thick sticky lava; and composite or stratovolcanoes which are large mountains formed by alternating explosive and effusive eruptions that build tall layers of ash and lava.

1. Volcanoes

16. Take a minute to label the parts on the diagram (not all parts are shown)

17. Magma chamber conduit mantle Parasitic Cone Ash Cloud/Gases Vent Lava Flow Crater

23. Can you identify the kinds of lava from the pictures? Circle your choice.

24. #1 AA

25. #2 Pahoehoe

26. #3 Pillow

27. #4 AA & PahoeHoe

43. Explosive Eruptions Mt. St. Helens Mont serrat Mt. Pinatubo

46. Cinder Cone Volcanoes

49. Sketch a Cinder Cone Volcano:

51. Shield volcano on Mars; Taken from space Shield Volcanoes Take a look at these examples: http://www.volcano.si.edu/world/tpgallery.cfm?category=Shield%20Volcanoes The Mauna Loa volcano in Hawaii—the largest volcano on Earth—has the broad expanse characteristic of shield volcanoes. It spreads across half the island of Hawaii.

53. Sketch a sheild Volcano:

56. Sketch a composite Volcano:

58. Mt St. Helens

61. Crater Lake