1. Volcanoes

3. Hot Spots- area of high temp. lava - made Hawaii

4. View From Space - Klyuchevskaya, Russia

5. Magma – molten rock beneath the surface Lava – molten rock on the surface

6. Types of Volcanoes
Composite Cone or

8. A Cinder Cone: Wizard Island at Crater Lake, Oregon

9. Icelandic Volcanoes

10. Eyjafjallajokull

11. Tuff Ring: Diamond Head, Hawaii

12. Shield Volcano: Mauna Loa, Hawaii

14. Stratovolcano or Composite Cone: Mount Shasta, California

15. Shastina and Landslide Deposit

16. Products of Eruptions Gases Lava Flows Steam Pyroclastic Debris
Carbon Dioxide
H2S
SO2
HCl HF
Lava Flows
Pyroclastic Debris
Bombs
Lapilli
Ash
Mudflows
Landslides

17. Environmental Hazards of Volcanoes
Pollution
SO2, HCl in Water
Lava Flows
Falling Ejecta
Ash Falls
Building Collapse
Crop Destruction
Mudflows
Direct Damage (Colombia, 1985)
Floods (Several Types)
Blast (Mt. St. Helens, 1980)
Pyroclastic Flow (St. Pierre, 1902)
Gas (Lake Nyos, Cameroon, 1986)

18. Pyroclastic Flow or Nuee- Ardente (French: Fiery Cloud)

19. How Calderas Form:

20. Crater Lake, Oregon

21. Colorado Volcanoes ?– La Garita

22. Evolution of Volcanoes
An active volcanic landscape

23. Evolution of Volcanoes
A volcanic landscape after a million years or so

25. Mount Hood is a stratovolcano in the Cascades of northern Oregon

26. The caldera at Crater Lake National Park cuts through the flanks of the former Mount Mazama (composite cone)

27. Layers of tephra on Usu (stratovolcano) in Japan
Layers of tephra on Usu (stratovolcano) in Japan. The crater by the volcanologists was formed in

28. Eruption of Galunggung (stratovolcano) in Indonesia.

29. 1980 eruption of Mt. Saint Helens produced 0. 1 cubic miles (0
1980 eruption of Mt. Saint Helens produced 0.1 cubic miles (0.5 cubic km) of ash.
Stratovolcanoes are associated with subduction zones, areas where dense oceanic plates are pushed beneath more buoyant continental plates.

30. The cinder cone in the above photo is Puu Lilinue on Mauna Kea in Hawaii.

31. Cinder cones are produced by "fire fountains," low-energy eruptions that propel fragments of lava 100s of feet into the air.

32. A volcanic dome is a steep-sided, rounded extrusion of highly viscous lava squeezed out from a volcano to form a dome-shaped, or bulbous, mass of lava above and around the volcanic vent

33. During the eruption of Redpubt volcano (Alaska) several lava domes grew and collapsed near the summit of the volcano.

34. Flood Basalts
The Columbia River basalts cover parts of the states of Oregon, Washington, and Idaho and are a famous example of flood basalts that produced a lava plain.

35. Lava
Eruptions under water or ice produce pillow lava (become pillow basalt)

36. Coastal Flows

37. "Pahoehoe" and "aa" are Hawaiian words used to describe the type of lava volcanoes have

38. Aa Flow

40. Pahoehoe

41. Lava Tubes