Midterm #2 Part 2 Flashcards
1
Q
Vent
A
Opening where main eruption occurs
2
Q
Crater
A
Depression at summit
3
Q
Caldera
A
Large depression
4
Q
Fissure
A
Crack where magma escapes
5
Q
Flanks
A
Sides of volcano
6
Q
Conduit
A
Pipe
7
Q
Felsic Magmas
A
- high viscosity
- silica > 75%
- high volatile content
- explosive, pyroclastic flows and clouds
8
Q
Mafic Magmas
A
- low viscosity
- silica about 50%
- quiescent eruptions, lava flows
9
Q
Shield Volcanoes 4
A
- broad, greatly sloping
- low viscosity flows, quiescent eruptions
- central vent
- spatter cones, lava tubes, fissures
10
Q
Splatter cones
A
- small steep sided cone
- solidifying lava flow
11
Q
Lava Tubes
A
- tunnel like
- associated with low viscosity, mafic lava
- develop after lava cools
- great distances
12
Q
Fissure eruptions 3
A
- linear volcanic vent
- flanks and base of volcanoes
- shield volcanoes
13
Q
Cinder cones 6
A
- symmetrical, steep sided
- pyroclastic material
- large central vent
- short lived
- mafic to intermediate magmas
- volcano flanks or fields
14
Q
Composite volcanoes 6
A
- layers of pyroclastic and lava flows
- intermediate to felsic magmas
- central vent
- gently sloping flanks
- geologically long lived
- violent eruptions
15
Q
Lava domes 4
A
- dome shaped
- form in one eruptions event
- high viscosity to felsic lava
- volcano flanks or capping vents
