Eruption types

Question 1

What is magma?

Answer 1

melted rock

Question 2

Traditionally and typically where is magma found?

Answer 2

under the Earth’s surface

Question 3

what is magma primarily composed of?

Answer 3

silica rocks

- 45 to 75 percent of silicate minerals

Question 4

magma is composed of ____ to ___ percent of silicate minerals

Answer 4

45 to 75

Question 5

which minerals is magma composed of

Answer 5

silicate

Question 6

temperatures of erupting lava range from..

Answer 6

800-1200 digress celsius

Question 7

What is one of the most important properties of magma?

Answer 7

its viscosity

Question 8

what is viscosity?

Answer 8

how thick a fluid is

Question 9

viscosity is how _____ a fluid is

Answer 9

thick

Question 10

fluids with high viscosity flow _____

Answer 10

slowly

Question 11

fluids with low viscosity flow _____

Answer 11

easily

Question 12

What two variables does a madams viscosity depend on?

Answer 12

temperature, silica content

Question 13

higher temperature magma has a _____ viscosity

Answer 13

lower

Question 14

the hotter the magma…

Answer 14

the more easily it flows

Question 15

magma that has more silica (felsic) has a _____ viscosity

Answer 15

higher

Question 16

if magma has high silica it…

Answer 16

flows more slowly

Question 17

magma that has less silica (mafic) has a _____ viscosity

Answer 17

lower

Question 18

less viscus magma lets gas escape more ______

Answer 18

easily

Question 19

dissolved gas content of magma depends on….

Answer 19

viscosity

Question 20

the nature of volcanic eruption depends on…

Answer 20

dissolved gas content

Question 21

if you have a lot of dissolved gas you will get a more ________ eruption

Answer 21

explosive

Question 22

more viscus magma…

Answer 22

holds more gas

Question 23

less viscous magma are ______ explosive

Answer 23

less

Question 24

different types of volcanoes form according to the different ______ that is being erupted at that point.

Answer 24

magma

Question 25

low viscosity lava erupting creates...

Answer 25

Hawaiian type eruption

Question 26

What do Hawaiian eruptions form?

Answer 26

- a type of volcano called shield volcanoes | - flood basalts

Question 27

shield volcanoes form from...

Answer 27

Hawaiion eruptions

Question 28

Hawaiian eruptions happened when there is...

Answer 28

low viscosity lava erupting

Question 29

shield volcanoes are _____ and _____ volcanoes

Answer 29

large, broad

Question 30

do shield volcanoes have explosive eruptions?

Answer 30

no

Question 31

flood basalts are the ______ eruptions of lava on Earth

Answer 31

largest

Question 32

What is the distance a flood basaltic eruption can exceed?

Answer 32

2000km

Question 33

How long can the individual lava flow of a flood basalt flow?

Answer 33

10 plus years

Question 34

Are flood basalts rare or common occurrences?

Answer 34

rare

Question 35

Flood basalts provide evidence that...

Answer 35

the earth goes through periods of enhanced volcanic activity

Question 36

major extinctions correspond with...

Answer 36

flood basalts

Question 37

what is thought to cause flood basalts?

Answer 37

combination of continental rifting on top of a mantle plume that just brings abnormally hot material to the surface, and as that material rises to the surface the pressure drops and causes even more melting. huge gush of magma to the surface

Question 38

Strombolian eruptions are created from _______ viscosity lava

Answer 38

intermediate

Question 39

Strombolian eruptions form volcanoes called...

Answer 39

cinder cones

Question 40

Cinder cones are _____ volcanoes made of loose volcanic rock

Answer 40

small

Question 41

Plinian eruptions are composed of magma that has _____ viscosity

Answer 41

high

Question 42

Plinian eruptions are _____ and _____

Answer 42

explosive, violent

Question 43

Plinian eruptions form volcanoes called...

Answer 43

stratovolcanoes - look like mountains, are tall, huge, have massive eruptions

Question 44

What are the three types of volcanoes?

Answer 44

shield, cinder cone, stratovolcano

Question 45

List the explosiveness of the types of explosions in order of least to most explosive.

Answer 45

1. Hawaiian 2. Strombolian 3. Plinian

Question 46

List the size of the types of volcanoes in order of largest to smallest

Answer 46

1. shield 2. stratovolcano 3. cinder cone

Question 47

What are four other features associated with volcanoes?

Answer 47

craters, calderas, geysers, fumaroles

Question 48

what are craters?

Answer 48

bowl-shaped depression at volcanoes summit

Question 49

What is a caldera?

Answer 49

larger depression from collapse due to emptying magma chamber

Question 50

What is the only difference between calderas and craters?

Answer 50

calderas are much larger

Question 51

How are geysers and fumaroles formed?

Answer 51

by hot water and gases from a nearby fuming magma chamber

Question 52

what type of volcanoes do convergent boundaries tend to form?

Answer 52

stratovolcanoes (silica-rich magma)

Question 53

where are volcanoes concentrated?

Answer 53

along plate tectonic boundaries.

Question 54

where do shield volcanoes tend to form?

Answer 54

along divergent boundaries