VOLCANOESVOLCANOES
Pompeii, ItalyPompeii, Italy
Bodies…Bodies…
Pompeii, ItalyPompeii, Italy
Terms to know…Terms to know…►Magma-Magma- liquid rock liquid rock►Lava-Lava- magma that breaks through to magma that breaks through to
the surface of the earththe surface of the earth►Vent-Vent- opening through which magma opening through which magma
flowsflows►Volcano-Volcano- structure formed by the vent structure formed by the vent
and the volcanic material that builtsand the volcanic material that builts►Pyroclastic material- Pyroclastic material- ash and rock ash and rock
material ejected from a volcanomaterial ejected from a volcano
VolcanoesVolcanoes
Where do volcanoes happen?Where do volcanoes happen?
►Subduction zones- Subduction zones- Pacific Ring of Pacific Ring of FireFire
►Mid-Ocean Ridges-Mid-Ocean Ridges- fissures (breaks fissures (breaks and cracks, Iceland)and cracks, Iceland)
►Hot Spots-Hot Spots- notnot along plate along plate boundaries- areas of volcanic activity boundaries- areas of volcanic activity within the platewithin the plate
Where?Where?
What erupts?What erupts?
►LavaLava►Mafic- oceanic, slow Mafic- oceanic, slow ►Felsic- continents, fastFelsic- continents, fast
►GasesGases►Rock fragments or Pyroclastic MaterialRock fragments or Pyroclastic Material
►Volcanic AshVolcanic Ash►Volcanic DustVolcanic Dust►Volcanic Bombs (hot) and Blocks (cold)Volcanic Bombs (hot) and Blocks (cold)
3 Types of Volcanoes3 Types of Volcanoes
► Shield VolcanoShield Volcano► Cinder ConeCinder Cone► Composite VolcanoComposite Volcano
Shield VolcanoShield Volcano
► Broad baseBroad base►Gentle sloping sidesGentle sloping sides► Covers a wide areaCovers a wide area► Lava builds up Lava builds up
slowly to form slowly to form volcano bodyvolcano body
►Quiet eruptionsQuiet eruptions►Hawaiian IslandsHawaiian Islands
Cinder ConeCinder Cone
► Explosive eruptionsExplosive eruptions► Very steep sides (40 Very steep sides (40
degrees or more)degrees or more)► Solid fragments Solid fragments
(pyroclastic (pyroclastic material) that are material) that are ejected make the ejected make the volcano bodyvolcano body
► Rarely more than a Rarely more than a few hundred meters few hundred meters highhigh
Composite VolcanoComposite Volcano
► Both explosive and Both explosive and quiet eruptionsquiet eruptions
► Body of volcano Body of volcano made of alternating made of alternating layers oflayers of lava lava (quiet (quiet eruptions)eruptions) and and pyroclastic pyroclastic materialmaterial (explosive (explosive eruptions)eruptions)
►Mt. St. Helens (USA) Mt. St. Helens (USA) and Mt. Fuji (Japan)and Mt. Fuji (Japan)
The Ring of FireThe Ring of Fire
►Ring Of Fire IMAX movieRing Of Fire IMAX movie►Other VideosOther Videos►Volcano Concept MapVolcano Concept Map►Plotting the Ring of FirePlotting the Ring of Fire