Midterm #2 Part 2

Question 1

Vent

Answer 1

Opening where main eruption occurs

Question 2

Crater

Answer 2

Depression at summit

Question 3

Caldera

Answer 3

Large depression

Question 4

Fissure

Answer 4

Crack where magma escapes

Question 5

Flanks

Answer 5

Sides of volcano

Question 6

Conduit

Answer 6

Pipe

Question 7

Felsic Magmas

Answer 7

• high viscosity
• silica > 75%
• high volatile content
• explosive, pyroclastic flows and clouds

Question 8

Mafic Magmas

Answer 8

• low viscosity
• silica about 50%
• quiescent eruptions, lava flows

Question 9

Shield Volcanoes 4

Answer 9

• broad, greatly sloping
• low viscosity flows, quiescent eruptions
• central vent
• spatter cones, lava tubes, fissures

Question 10

Splatter cones

Answer 10

• small steep sided cone

- solidifying lava flow

Question 11

Lava Tubes

Answer 11

• tunnel like
• associated with low viscosity, mafic lava
• develop after lava cools
• great distances

Question 12

Fissure eruptions 3

Answer 12

• linear volcanic vent
• flanks and base of volcanoes
• shield volcanoes

Question 13

Cinder cones 6

Answer 13

• symmetrical, steep sided
• pyroclastic material
• large central vent
• short lived
• mafic to intermediate magmas
• volcano flanks or fields

Question 14

Composite volcanoes 6

Answer 14

• layers of pyroclastic and lava flows
• intermediate to felsic magmas
• central vent
• gently sloping flanks
• geologically long lived
• violent eruptions

Question 15

Lava domes 4

Answer 15

• dome shaped
• form in one eruptions event
• high viscosity to felsic lava
• volcano flanks or capping vents

Question 16

Composite Volcano Tectonics

Answer 16

• subduction zones
• intermediate magma and violent eruptions
• convergent plate boundaries

Question 17

Cinder come tectonics

Answer 17

• rift zones
• mafic magma and short lived eruptions
• divergent plate boundaries and hot spots

Question 18

Shield volcano tectonics

Answer 18

• hot spots
• mafic magma and quiescent eruptions
• some at divergent plate boundaries

Question 19

Pyroclastic flow

Answer 19

• fast moving current of hot gas and tephra

- 100 km/h

Question 20

Lahar

Answer 20

• volcanic mudflows
• melted ice mixed with ash
• rain mixed with ash

Question 21

Volcanic forcing

Answer 21

• climate forcing factor
• operates independently of climate system
• NOT affected by climate change

Question 22

Volcanic soils

Answer 22

• andisols, adosols, vitriol’s, volcanic ash
• fertilizing elements
• grapes, coffee, kiwi

Question 23

Hilo soil

Answer 23

• state of Hawaii
• bedrock
• red colour
• coffee