A volcano is an opening on the surface of the earth where melted rock (called magma) is ejected above the surface of the earth as lava.

volcanoes occur where tectonic plates come into contact with one another. there are approximately 1,000 active volcanoes in the world, many of them in an area known as the "Ring of Fire" which circles the Pacific Ocean.

Primary Types of Volcanoes

• cinder cone
• composite volcano
• shield volcano
• lava dome
• submarine volcano

Types of Eruptions

• based on the form of the vent:
  
  
  • fissure eruption
  • central vent eruption
  
  
  
• based on the degree of explosiveness:
  
  
  • effusive eruption
  • explosive eruption
  • mixed eruption
  
  
  
• based on the resemblance to specific volcanoes:
  
  
  • plinian eruption/vesuvian eruption
  • hawaiian eruption
  • peleean eruption
  • vulcanian eruption
  • strombolian eruption
  
  
  
• miscellaneous types of eruptions:
  
  
  • phreatic eruption
  • phreatomagmatic eruption
  • basaltic flood eruption
  
  
  

Types of Ejected Materials (volcaniclastic particles)

• pyroclast
• hydroclast
• autoclastic fragments
• alloclastic fragments
• epiclast