Volcanoes

Guide Note

Volcanoes are created when hot magma rises to the surface of the Earth's crust and breaks through. Most volcanoes are located on the boundaries of tectonic plates. The term volcano refers to the opening where the molten rock and gases are expelled. Volcanoes are mountains, but they are not like typical mountains. Instead, a volcano is built by the accumulation of its own eruptive products.

All volcanoes occur when hot magma rises to the surface and finds a weak spot in the earth's outer crust. When they break through the earth's crust this produces lava which spews out. This lava flow can reach speeds of up to 60 miles per hour and temperatures of 1,300 degrees Fahrenheit. The lava flow destroys everything in its path.

Fast Facts

1. Largest active volcano: Mauna Loa
2. Hawaii formed by 5 volcanoes
3. Magma: liquid rock inside a volcano
4. Lava: liquid rock that flows out of the volcano
5. More than 1500 active volcanoes
6. Can alter the climate for both long and short periods
7. Release large amounts of sulfur compounds into the air
8. Release large amounts of water and carbon dioxide
9. Hazardous to life and property
10. Capable of destroying all life for many miles in a matter of minutes

1. Cinder cones
2. Composite volcanoes
3. Shield volcanoes
4. Lava domes

1. Stay away from active volcano sites
2. Evacuate immediately from a volcano area
3. Be aware of mudflows
4. Wear long sleeve shirts, long pants and goggles to protect from falling ash
5. Avoid areas down wind of a volcano
6. Stay indoors till ash has settled
7. Close doors and windows