1. High Cascades Modern Volcanoes of the Pacific NW Mt. St. Helens, July 27, 2005

2. Volcanic Episodes 65 55 45 35 25 15 0 5 Age (Myrs) Western Cascade Arc (37-15 Myrs) Challis Arc (55-42 Myrs) High Cascade Arc (5-0 Myrs) Columbia River Basalts (17-6 Myrs, Most 17-14 Myrs) Yellowstone Hot Spot (14-0 Myrs)

3. West & High Cascades G-1 West Cascade Arc (37-15 Myrs) High Cascade Arc (5-0 Myrs)

4. Cascade Volcanoes G-1

5. Why Do Cascade Volcanoes Exist at All? Subduction

6. Cascade Eruptions 4000yrs

7. Historic Cascade Eruptions G-4

8. Cascade Volcanoes G-1

9. Mt Baker

10. Glacier Peak

11. Glacier Peak Ash Fall 13,100 yr tephra - in inches

12. Mt. St. Helens April 1980

13. 1980 Eruption - Ash Cloud

14. 1980 Eruption

15. Damage

16. Blast / Pyroclastic Flow

17. Lahars

18. 2004-6 Eruption October 1, 2004

19. 2005 Dome 81 Million Cubic Meters as of April, 2006

20. 2005 Dome February 22, 2005

21. July 27, 2006 Feb, 2005 Current Dome Growth

22. Thermal Image - July 27, 2006 Time-lapse animation

23. June 29, 2006