Classroom presentations to accompany Understanding Earth , 3rd edition

1. Classroom presentations to accompany Understanding Earth, 3rd edition prepared by Peter Copeland and William Dupré University of Houston Chapter 5 Volcanism

2. Volcanoes

3. Plumbing System of a Volcano Fig. 5.1

4. May 1990 Eruption of Kilauea, Hawaii James Cachero/Sygma

5. Major difference between plutonic and volcanic rocks is texture, a reflection of cooling rate. Volcanic rocks

6. Nonvolatile material Material ejected from volcanoes • Lava: magma that has flowed on the surface of the Earth. • Tephra: fragments that solidified in the air during eruption.

7. aa pahoehoe Types of Lava

8. Aa Lava Pahoehoe Lava Fig. 5.3 Kim Heacox/DRX

9. Columbia Plateau Flow Basalts Fig. 5.2 Martin G. Miller

10. Pyroclastic flow Air-fall Mudflow (lahar) Tephra

11. Mixture of hot gases, ash, and rocks forming a super-heated and dense current capable of moving 150 km/hr. Pyroclasticflow (nueé ardente)

12. Pyroclastic Flow from the 1998 Eruption on Montserrat R.S.J. Sparks

13. Escaping a Pyroclastic Flow at Mount Unzen, Japan, 1991 Fig. 5.9 AP/Wide World Photos

14. Volcanic Bomb Fig. 5.7 Science Source/Photo Researchers

15. Volcanic Breccia Fig. 5.8 Doug Sokell/Visuals Unlimited

16. Pillow basalt Phreatic explosions Submarine eruptions

17. Pillow Lava Fig. 5.4 Woods Hole Oceanographic Institute

18. Phreatic Explosion in the Pacific Fig. 5.18 Maritime Safety Agency, Japan

19. Vesicular Basalt Fig. 5.5 Glen Oliver/Visuals Unlimited

20. Pyroclasic Eruption at Arenal Volcano, Costa Rica Fig. 5.6 Gregory G. Dimijian/Photo Researchers

21. Shield volcanoes Stratovolcanoes (composite) Domes and cones Fissure eruptions (flood basalts) Submarine eruptions Eruptive styles and landforms

22. Low-viscosity lava flows Low-silica magma — mafic Basalt Pahoehoe Aa Gently sloping flanks — between 2 and 10 degrees Tend to be very large Spatter cone — minor feature Shield volcanoes

23. Shield Volcano Fig. 5.10

24. Olympus Mons Shield Volcano NASA, Viking Orbiter 1

25. Formed of pyroclastics only Steep sides — ~30 degrees Relatively small Short duration of activity Cinder cones

26. Cinder Cone Fig. 5.12

27. Cerro Negro Cinder Cone, near Managua, Nicaragua in 1968 Fig. 5.13 Mark Hurd Aerial Surveys

28. Forms above a volcanic vent Viscous lava — usually silica-rich (or cooler magma) Associated with violent eruptions Volcanic domes

29. Fig. 5.11

30. Inyo Obsidian Domes-California P. L. Kresan

31. Lava Dome Fig. 5.11 Lyn Topinka/USGS

32. Alternating pyroclastic layers and lava flows Slopes intermediate in steepness Intermittent eruptions over long time span Mostly andesite Distribution Circum-Pacific Belt (“Ring of Fire”) Mediterranean Belt Composite volcano

33. Composite Volcano Fig. 5.14

34. Mt Fujiyama, Japan Fig. 5.15 Raga/The Stock Market

35. Before May, 1980 Emil Muench/Photo Researchers

36. After May, 1980 David Weintraub/Photo Researchers

37. Depression at top of volcano produced during an eruption May have younger domes within it Caldera

38. Fig. 5.16

39. Crater Lake, Oregon Fig. 5.17 Greg Vaughn/Tom Stack

40. Shiprock, New Mexico an exposed volcanic pipe (diatreme) Fig. 5.19 Fred Padula

41. When low-viscosity lava is issued from cracks in the Earth tens of kilometers long. Fissure eruptions

42. 1971 Fissure Eruption, Kilauea, Hawaii

43. Fissure Eruptions Form Lava Plateaus Fig. 5.20

44. Laki fissure (Iceland) erupted in 1783 extruding the largest lava flow in human history. Fig. 5.21 Tony Waltham

45. Mafic lava — solidifies to basalt Fissure flows Plateau basalts Columnar structure or jointing Lava floods

46. Fig. 5.22

47. Columbia Plateau Flow Basalts Fig. 5.2 Martin G. Miller

48. Welded Tuff: California Fig. 5.23 1 foot Gerals and Buff Corsi/Visuals Unlimited

49. Ash-flow Sheets Draping Topography, Japan Fig. 5.24 S. Aramaki

50. Caution: Volcanologist at Work Fig. 5.25 Maurice Krafft/Photo Researchers