Chapter 9 Study Guide Flashcards
(41 cards)
A body of molten rock deep underground that feeds a volcano, where molten rock gathers
Magma chamber
Areas of Earth’s surface through which magma and volcanic gasses pass
Volcano
An opening at the surface of the earth through which volcanic material passes
Vent
The most common type of volcanic eruption
Nonexplosive
Eruptions that produce relatively calm flows of lava
Nonexplosive
Rare type of eruption that can be incredibly destructive
Explosive
An eruption where clouds of hot debris, ash, and gas rapidly shoot out from a volcano
Explosive
The key to whether an eruption will be explosive
The silica, gas, and water content of the magma
Liquid magma that flows from a volcanic vent
Lava
Magma that is blasted into the air and then hardens
Pyroclastic material
The type of material produced by a nonexplosive eruption
Lava
The type of material produced most by explosive eruptions
Pyroclastic material
Molten rock, blown into tiny particles, that harden in the air, and can circle the earth for years
Ash
The viscosity of stiff lava
High viscosity
The viscosity of more fluid-like lava, or runny
Low viscosity
Two types of high viscosity lava
Blocky
Pahoehoe
Two types of low viscosity lava
Aa
Pillow
Lava that pours out quickly and forms a brittle crust leaving jagged pieces
Aa
Lava that flows slowly, has a glassy surface, and rounded wrinkles, like wax from a dripping candle
Pahoehoe
Lava that forms when lava erupts under water and forms rounded lumps
Pillow
Cool, stiff lava that does not travel far from the erupting vent, and forms jumbled heaps of sharp chunks
Blocky lava
Large blobs of magma that harden in the air
Volcanic bombs
Pebble-like bits of magma that harden before they hit the ground
“Little stones”
Lapilli
Forms when gasses in stiff magma expand rapidly, and the walks of the gas bubbles explode into tiny, glasslike slivers. Makes up most of the pyroclastic material
Volcanic ash
