Volcano Notes What materials erupt from Volcano 1

Volcano Notes What materials erupt from Volcano? 1. Gases 2. Molten Rock 3. Solid Fragments

GASES • • STEAM is most abundant, 66% Other gases CO 2, N, S, H, Cl, Ar, F White clouds: indicate STEAM Bluish/brown: indicate SULFUR

FUMAROLE • Crack in a volcano • Temps range 200400 degrees • Alaska’s Valley of 10, 000 Smokes • SOLFATARA: special fumarole, releases SULFUR

Gases: determine eruption • EXPLOSIVE: thick magma, trapped gases, Ex: Mt Pelee • GENTLE: magma is fluid, gases can escape, Ex: Hawaii

Trapped gases underground • HOT SPRINGS form when groundwater boils • GEYSER is special type that erupts periodically

MOLTEN ROCK • MAGMA: melted rock below the earth’s surface • LAVA: melted rock above the earth’s surface

Types: • AA: rough, jagged, sharp lava • PAHOEHOE: smooth, satin-like, ropey lava

Examples: • PILLOW LAVA: forms when lava flows into the ocean • PILLAR LAVA: as lava cools, surface shrinks, forms hexagonal columns

SOLID FRAGMENTS • • • DUST: smallest ASH: next largest LAPILLI: grape-sized CINDERS: glassy BOMBS: tear-dropped BLOCK: largest TUFF: combination PUMICE: light gray rock, floats SCORIA: heavier, more red

Lapilli, Bomb, Pumice, Block

NUEE ARDENTE • A mixture of steam, other gases, pumice, ash • Flows down hill like an avalanche

Sources of Magma • BATHOLITH: larger than 40 square mi • STOCK: less than 40 square mi • LACCOLITH: Domed surface • DIKE: vertical intrusion • SILL: horizontal intrusion • PIPE: connects • NECK: center of cone • DOME: may form

FISSURE or RIFT • Crack in the surface of earth • Magma escapes • May be miles long

Top of Volcano: • CONE: visible part of volcano, the rim is called the crater • If rim collapses and enlarges it is called a CALDERA