Kinds of Volcanoes
  Kinds of
Lava Flows		 Disaster
Agencies
 
 
                 
USGS Photograph   USGS Photograph    
Stratovolcano   Cinder Cone Volcano    
Stratovolcanoes are shaped like a cone, but have very steep sides. They are formed during violent eruptions by lava flows, tephra, and pyroclastic flows. They are formed by several vents that lead from deep underground and may form cinder cones nearby.   Cinder cones are steep sided hills made up of fragments from a volcanic eruption. The fragments that form these cinder cones are blown down wind from an eruption from a stratovolcano. You can see the stratovolcano that formed this cinder cone in the background.  
       
       
USGS Photograph   USGS Photograph  
   
Shield Volcano   Mud Volcanoes  
Shield volcanoes are the largest volcanoes on earth. They are built by basalt lava flows and have gentle slopes that move from the top of the volcano to the bottom.   Mud volcanoes are the smallest of the volcanoes. They are only 2-3 meters/6-9 feet tall. They are built from by a mixture of hot water and sediments from an eruption by another larger volcano.  
       
       
USGS Photograph   USGS Photograph    
Lava Dome   Caldera    
Lava domes are built by a kind of viscous lava. Viscous lava is a thick mixture that can not flow quickly, so the lava cools too quickly to really move any distance from the eruption.   A caldera is an area at the to of a volcano that has collapsed. After eruptions, when the area below the top is sometimes empty, the bottom falls out and the top crashes down. Calderas are not craters.    
         
   
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Photographic Citations:
Photograpic Citations can be found by passing the mouse over the picture.


Text Bibliography:

USGS Volcanoes: Volcano Picture Glossary
http://volcanoes.usgs.gov/Products/Pglossary/pglossary.html