1. What is a Volcano?

2. http://video. nationalgeographic. com/video/101-videos/volcanoes-101

3. A Volcano is a place where lava reaches the surface

4. How does it happen?

5. Plate Tectonics & Hotspots
Divergent plate boundaries
Convergent plate boundaries
Hotspots
The pulling apart of plates, causing molten
The
pulling apart of plates, causing molten rock to come to the top of the mantle. Causes mainly submarine volcanic activity and creates new oceanic crust.
rock to come to the top of the mantle. Causes mainly submarine volcanic activity and creates new oceanic crust.
The c The collision of plates, causing
The collision of plates, causing Subduction or one plate to submerge beneath the other late to submerge beneath the other plate to submerge beneath the other ollision of plates, causing Subduction or.
Located away from tectonic plates, over mantle plumes where pipes vent magma.
Volcanoes formed over hotspot go dormant and new ones are formed when plates move overhead.

6. Divergent Plate Boundaries
Most divergent plate boundaries are at the bottom of the oceans, causing most of the volcanic activity to be under water, thus forming new seafloor.

7. Convergent Plate Boundaries
When two plates (usually an oceanic and continental plate) collide, causing the one plate to submerge under the other plate (called subducting). In the case of oceanic-continental, a deep trench just off shore is formed.
When the viscous magma, reaches the surface, a volcano is formed.
*This is what caused the typical Ring of Fire volcanoes.*
Oceanic - Continental convergence
Continental - Continental convergence
Oceanic - Oceanic convergence

8. Hotspots
Located over a mantle plume, where the convection of the Earth’s mantle creates a column of hot material that rises until it reaches the crust. Pipes form in the crust, which vents magma.

9. Ring of Fire
Result of plate tectonics and the movement and hitting of crustal plates.
Area where large numbers of earthquakes and volcanic eruptions occur in a 40,000km horseshoe shape. Contains 452 volcanoes, with over 75% of worlds active and dormant volcanoes.

10. There are 3 types of Volcanoes
Shield Volcano
Cinder Cone Volcano
Composite Volcano

11. Shield Volcano
A gently-sloped volcano

12. Cinder Cone
A volcano made of cinders that are blown into the air

13. Composite Volcano A volcano built of alternating layers of cinders and
lava

14. What kind of volcano is this?

15. Diamond Head is an eroded Cinder (Tuff) Cone
Early sailors mistakenly thought glistening calcite crystals inside the tuff rocks were diamonds, leading to the incorrect name. Diamond Head formed when hot magma rising up a conduit hit ocean water, causing large explosions that threw exploded magma particles (tuff) into a broad ring.

16. What kind of Volcano is this?

17. Mount Shasta is a composite volcano
Over the last 10,000 years, Mt. Shasta has erupted on average once every 800 years. During the 3,500 years the volcano has erupted about once every 300 years. The most recent eruption may have occurred in 1786 A.D.
California

18. What kind of volcano is this?

19. Kohala is a shield volcano.
Kohala is the oldest of the subaerial volcanoes that make up the Island Of Hawaii. Kohala is considered to be extinct because it has not erupted for 60,000 years.
Hawaii