Introduction to volcanoes, shape, lava, landforms, resources.

1. Volcanoes

3. Geyser (Old Faithful)

6. Lava flows

7. Basalt

8. Aa lava

9. Mr..Cooke will be in school late today

10. Rhyolite (left) and Basalt (right)

11. Andesite

13. Volcano Irazu Costa Rica

15. Pyroclastic flow

17. Pyroclastic flow Mount Pelee

19. Lahar

21. Lahar

22. Case study of Mount Hood Mount Hood from Portland, Oregon. When Mount Hood next erupts, Portland could be affected by light ashfalls similar to those it experienced during the 1980 eruptions of Mount St. Helens. The city will not be directly affected by lava flows, pyroclastic flows, or lahars, but regional transportation and water supplies could be disrupted. (Photo by David Wieprecht, USGS)

24. Subduction of the Juan de Fuca Plate under the North American Plate controls the distribution of earthquakes and volcanoes in the Pacific Northwest. Mount Hood is just one of several recently active, major volcanic centers in the Cascade Range.

26. Note that most of the volcanic hazards have been displayed by Mount Hood at one time or other. The volcano very often changes the materials it erupts – this is due to complex changes in the chemistry of the magma supply.

27. One way to protect against volcanic hazards is to zone the land around them

28. Gas eruptions

34. Lake Nyos (Cameroon)

36. Mt. Pinatubo

38. Effect of dust emissions from Pinatubo

42. Shield volcano (Mauna Loa)

44. Shield volcano - features

47. Mount St. Helens

49. Composite or strato volcano

50. Cinder cone (Mt. Paricutin, Mexico)

53. Pinatubo

56. St. Helens (before and after)

58. Paricutin (Mexico)

61. Here is one of the volcanoes which has been developed as a water resource in New Zealand

62. Mineral deposits Sulphur mine not far from Mt. Hood

65. Geothermal energy

66. Geothermal project in the US

67. Soils – agricultural potential

69. Tourism (let’s go!)

70. Tourism (great fishing spot!)

71. Tourism

72. Lava fountains (Mauna Loa)

73. Kilauea (Hawaii)

74. Lava flow, Kilauea

78. Devil’s Tower Wyoming

79. Mount Rushmore (granite outcrop)

80. Granite