1. Mt. St. Helens, Washington

2. Plug

3. Cascades

4. Bomb Aerodynamically shaped

5. Pyroclastic Flow >1000 o F >100MPH Poisonous gas

6. Mount Pelee 1902 Damage done by pyroclastic flow

7. St. Helens 1 Mt. St. Helens eruption First signs of an eruption: 1) Gas emissions, the more the better. 2) Increased seismic activity.

8. St. Helens Bulge Bulge grew up to 3 feet per day!

9. St. Helens Lateral Blast Bulge collapsed, resulting in a large landslide. Magma chamber exposed.

10. St. Helens Main Blast

12. St. Helens Before Mt. St. Helens before…

13. St. Helens After Mt. St. Helens after.

14. Mt. Rainier 4X Mt. St. Helens Steepest part of mountain faces Seattle

15. Villarrica volcano, Chile

16. Lahar Hot mud flow

17. Nevado del Ruiz volcano

18. Lahar Consistency of flowing concrete

19. Village

20. Rainier Lahars

22. Volcanoes of The World

23. Famous Volcanic Eruptions Year without a summer in NE Sound heard 4000 miles away Largest eruption in past 100 years

24. Caldera Volcanoes Yellowstone: Eruption every 600,000 years Last eruption: 2500km 3 of material Toba: 90,000 years ago. Reduced Earth’s human population to about 5000 people.

25. Long Valley Caldera Map

26. Long Valley Caldera

27. Caldera Collapse

28. Bishop Tuff

29. Yellowstone Hot Spot

30. Yellowstone

31. Yellowstone Fallout

32. Volcanic Aerosols SO 2 Mt. Pinatubo, 1991: 20 tons 1.5 0 F cooling for two years Tambora, 1815: >100 tons 2 0 F cooling

33. Zones of Volcanism