Volcanoes Types of volcanoes ShieldLava pours from an

Volcanoes • Types of volcanoes: Shield—Lava pours from an opening (called a vent) creating gently sloping sides, flat and round. Example: Mauna Loa (Hawaii) or Mauna Kea (page s 112 -113 red book)

Volcanoes Cinder cone—Created by an explosive eruption out of the ground creating steep sloping sides and a narrow base. This type can spew lava, cinders, ash and tephra (volcanic rocks). After erupting tends to be inactive and erodes easily. Example: Paricutin Mexico (page s 113 red book)

Volcanoes Composite—formed by layers of lava and tephra has steep slopes and broad bases, also called Stratovolcanoes Example: Vesuvius, Mt. St. Helens, Mt. Fuji (dormat) (page s 113 red book)

Volcanoes • Types of Lava Basaltic magma—dark colored with lots of water, low in silica produces quiet nonexplosive eruptions. Hawaiian term: pahoehoe— very thin liquid lava forms ropelike structure when cools aa—when hardened crust of lava flow breaks into jagged chunks Silica-rich or granitic magma—light colored lava causes explosive eruptions

Volcanoes • Projectile terms: volcanic dust—smallest particle volcanic ash—rock particle size of rice grains volcanic bombs—larger rock particles a few centimeters to several meters cinders—golf ball size volcanic bombs Ring of fire—along the pacific plate approximately 300 volcanoes