3 states

Opening that erupts gases, ash, & lava


Over 600 active volcanoes


active, dormant-sleeping, extinct-dead!




Land of Fire & Ice

Hawaiian volcano, world’s most active, has been erupting for 25 years


Iceland, has glaciers and volcanoes, is part of Mid-Ocean Ridge






Rock melted by heat & pressure deep inside Earth


Less dense than mantle-“floats” to surface


Magma that reaches the surface






Opening in Earth, mouth of a volcano, lava comes out


Steep bowl-shaped area around a vent




Mountains formed of layers of lava, ash, and rocks from the vent


Dangerous-lava flows, ash clouds, exploding rocks, poisonous gases

Lava flows


Pyroclastic flow

Lava runs downhill, can be slow


Ash, rocks, and other matter (not lava), rushing down side of volcano-very dangerous!


Mostly form at divergent and convergent boundaries

Divergent forms a fissure or trench volcano


Convergent forms at subduction zone-more explosive!


Hot spots

NOT near plate boundaries-weak spot in crust where magma is near surface.


Hawaiian Islands, Yellowstone National Park

3 types of volcanoes

Shield, not tall-formed only from lava-Hawaiian volcanoes


Cinder cone-formed from pyroclastic explosions, very steep


Composite volcano-formed from layers of lava and pyroclastic explosions.