1. Volcanic Landforms 6 th Grade

2. 2 Kinds of Volcanic Eruptions Quiet Eruptions: – If magma is low in silica – Lava is low in viscosity and flows easily Explosive Eruptions: – If magma is high in silica – Lava is high in viscosity and flows slowly – Explosive eruptions breaks lava into fragments that quickly cool and harden into pieces of different sizes like ash, cinders, bombs in a pyroclastic flow

3. Pyroclastic Flow: when an explosive eruption hurls out a mixture of hot gases, ash, cinders, and bombs Ash: fine, rocky particles as small as a speck of dust Cinders: pebble-sized particles Bombs: large particles that range from the size of a baseball to the size of a car

4. Volcanic Ash Cloud http://www.youtube.com/watch?v=Jav4- GLXecQ http://www.youtube.com/watch?v=Jav4- GLXecQ

5. Volcanic Eruptions create landforms made of lava, ash, and other materials. 4 Types of Landforms: 1) Shield Volcanoes 2) Cinder Cone Volcanoes 3) Composite Volcanoes 4) Lava Plateaus

6. Types of Volcanoes: Composite, Cinder Cone, and Shield

7. Shield Volcano

8. Shield Volcanoes

9. Shield Volcano

12. Shield Volcanoes

13. Characteristics of a Shield Volcano A short, but wide, broad volcano (can be as much as 4 miles wide!) Caused by thin layers of basaltic lava with low viscosity Caused by quiet eruptions has a caldera (large, cauldron-shaped crater) on top Hawaiian Islands are made up of shield volcanoes (including Mt. Kilauea and Mouna Loa –2 of the most active volcanoes in the world!) Very little pyroclastic material

14. Cinder Cone Volcanoes

20. Cinder Cone

21. Cinder Cone Volcanoes A volcano with a steep slope and a large crater Lava has a high viscosity Ex. Paricutin in Mexico built up a cinder cone 400 meters high

22. Composite Volcanoes

26. Tall volcanoes with small craters Alternate between quiet eruptions and explosive eruptions Alternate between lavas that contain basalt and lavas that contain rhyolite ex. Mount St. Helens in Washington State and Mount Fuji in Japan

27. Composite Volcano

29. Lava Plateaus Eruptions of lava that form flat, level areas Thin, runny lava flows out of long cracks and then cools and solidifies Ex. Columbia Plateau covers parts of the states of Washington, Oregon, and Idaho

30. Lava Plateaus