Volcanoes

Question 1

What is a shield Volcano?

Answer 1

Large with broad, gentle slopes with gentle eruptions

Question 2

What color is the lava from shield volcanoes?

Answer 2

Dark colored

Question 3

What is a stratovolcano (composite)?

Answer 3

Small but tall with violent, sticky eruptions

Question 4

What color is the lava from stratovolcanoes?

Answer 4

Light colored

Question 5

Shield volcanoes have more

Answer 5

Volume

Question 6

Hawaiian

Answer 6

Gentle outpourings of runny lava

Question 7

Rift eruptions

Answer 7

Gentle outpourings of runny lava from a linear rift rather than a crater

Question 8

Lava Fountain

Answer 8

Vigorous eruption with runny lava. Powered by gas

Question 9

Cinder Cone

Answer 9

Piles of volcanic “cinders” (small blobs of cooled lava from the fountain)

Question 10

Strombolian

Answer 10

Mildly explosive fountaining. Thicker, more viscous

Question 11

Vulcanian

Answer 11

Moderately explosive. Ash plume <5 km

Question 12

Pelean and Plinian

Answer 12

Strongly explosive. High and large ash clouds and eruption volumes

Question 13

What is more powerful, Pelean or Plinian?

Answer 13

Plinian

Question 14

What is a phreatic eruption?

Answer 14

Lava interacts with water or ice

Question 15

Surtseyan

Answer 15

Lava interacts with seawater

Question 16

What is an explosive eruption

Answer 16

Cooler, more viscous lavas reach the surface

Question 17

Eyjafjallajokull

Answer 17

Explosive eruption powered by the melting and boiling of glacial ice

Question 18

Ubehebe crater

Answer 18

Explosion caused by interaction between lava and groundwater

Question 19

Caldera

Answer 19

Larger than a crater, formed by the collapse of the surface into the lava chamber after it has been emptied by a large eruption

Question 20

Gentle eruptions

Answer 20

Shield, dry, mafic

Question 21

Where do gentle eruptions happen

Answer 21

Divergent boundaries

Question 22

Violent eruptions

Answer 22

Strato, wet, felsic

Question 23

Where do violent eruptions happen

Answer 23

Convergent boundaries

Question 24

Which is underground

Answer 24

Magma

Question 25

Which isn't underground

Answer 25

Lava

Question 26

How do pyroclastic flows form

Answer 26

Collapse of ash cloud

Question 27

Up to what speeds are pyroclastic flows travelling?

Answer 27

700 km/hr

Question 28

Up to what temperatures are pyroclastic flows

Answer 28

1000C

Question 29

What volcanic hazard destroyed Pompeii and Saint-Pierre?

Answer 29

Pyroclastic flow

Question 30

What is a Lahar

Answer 30

Fast, high volume mudslides triggered by the melting of ice or breaking crater lakes

Question 31

Why is a lava flow dangerous

Answer 31

Not because it's fast, but because they are generally unstoppable

Question 32

Basaltic (Gentle) lava speed

Answer 32

60 km/hr in channels and tubes, <6km/hr at flow fronts

Question 33

Nyiragongo lava speed + how much it killed

Answer 33

100 km/hr, killed 70

Question 34

What are toxic gasses

Answer 34

Gasses often confined to crater and ash cloud

Question 35

Lake Nyos

Answer 35

Massive CO2 release in 1986 that killed 1700 people and 6000 heads of cattle

Question 36

Ash Falls

Answer 36

Buries stuff and shreds lungs

Question 37

Earthquakes and landslides

Answer 37

Caused by the movement of lava; Can be a sign of eruptions or other hazards

Question 38

Mitigation 1: Monitoring

Answer 38

Look for -Earthquake activity -Heatflow -Ground movement and shape -Gas emissions

Question 39

Mitigation 2: Preparation

Answer 39

Successful evacuations vs. false alarms; long-term predictions in danger assessment maps

Question 40

What factors determine wether the volcano will erupts effusively vs. explosively?

Answer 40

Magma composition and water content

Question 41

What is an effusive eruption

Answer 41

Steadily flows from the volcano to the ground

Question 42

Are phreatic eruptions common at mid-ocean ridges?

Answer 42

No. Mid-ocean ridges are thousands of feet underwater and there is too much pressure for steam explosions when the lava touches the water

Question 43

What kind of magma forms shield volcanoes

Answer 43

Basaltic Magma

Question 44

What kind of magma forms stratovolcanoes

Answer 44

Andesitic/rhyolitic magma