Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Earth Science > Volcanoes > Flashcards

Volcanoes Flashcards

1
Q

Igneous rocks form as _____ rocks _____ and ______

A
  • molten
  • cool
  • solidify
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

intrusive/plutonic rocks

A

rocks that crystallize at depth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

extrusive/volcanic rocks

A

magma that reaches the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Magma consists of which 3 components?

A
  • melts
  • solids
  • volatiles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

solids are generally _______ that have already _______ from the melt

A
  • silicate minerals

- crystallized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

volatiles

A

gases dissolved in the melt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

rocks in the lower crust and upper mantle are near their _____ and any extra heat may induce ______

A
  • melting points

- melting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

an ______ in confining pressure causes an ______ in a rock’s melting temperature

A

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when confining pressures drop, _____ occurs

A

decompression melting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

most volcanoes are located within or near ______

A

ocean basins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

the main source of basaltic magma is

A

spreading centres slong mid-ocean ridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

hot spots form ______ sources in oceanic crust and ______ sources in continental crust

A
  • basaltic magma

- felsic magma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

magma at depth is ____ dense than the surrounding rock

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

magma differentiation

A

• Separation of a melt from earlier formed crystals to form a different magma composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

assimilation

A

Changing a magma’s composition by incorporation of foreign matter (country rock) into a magma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

fractional crystallization

A

progressive changes in the chemistry of slowly cooling magma because of sequential crystallization of different minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

batholith

A
  • largest intrusive body

- frequently form the cores of mountains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Largest known eruption

A

Yellowstone, 2500 km3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

shield volcanoes are _______ and composed primarily of _______

A
  • broad and slightly dome-shaped

- basaltic lava

20
Q

shield volcanoes are produced by

A

mild, eddusive eruptions of large volumes of lava

21
Q

composite/stratovolcanoes are ______

A

large, classic-shaped volcanoes

22
Q

cinder cones are built from _______, are ______ in size, and frequently occur in ______

A
  • ejected lava
  • small
  • groups or on flanks of other volcanoes
23
Q

domes are a _____ mass of ______, and can block openings leading to _______ of _______ magma

A
  • bulbous
  • congealed
  • explosive eruptions
  • gas-rich
24
Q

crater

A

steep-walled depression at the summit, generally <1 km diameter

25
Q

vent

A

opening connected to the magma chamber via a pipe

26
Q

caldera

A
  • large depression at the summit of a volcano
    -formed when magma is
    withdrawn/erupted from a shallow underground magma reservoir
27
Q

as magma reaches Earth’s surface, which 3 things occur?

A
  • crystallisation
  • fractionation
  • exolution of volatiles
28
Q

Which factors control eruptive style by increasing explosivity?

A
  • silica content
  • volatile content
  • high viscosity
29
Q

Subduction zones can be _____ and _____

A
  • continental/oceanic

- oceanic/oceanic

30
Q

rift zones/spreading centres and hot spots can be _____ and _____

A
  • oceanic

- continental

31
Q

Lava flows move _____ and reach temperatures of _____

A
  • slowly

- 500 to 1,000 degrees C

32
Q

Aa basaltic lava has ____ viscosity, _____ texture, and forms _____ surfaces

A
  • high
  • blocky
  • rough
33
Q

Pahoehoe basaltic lava has _____ viscosity, _____ texture, and forms ______ surfaces

A
  • low
  • ropey
  • smooth, unbroken
34
Q

eruption columns can ______ and have potential _____ effects

A
  • collapse

- climatic

35
Q

tephra fall is transported by _____, causes _____ collapse, ______ illness, and lead to ______

A
  • wind and rain
  • building
  • respiratory
  • lahars
36
Q

ash impacts _____

A

airplanes

37
Q

pyroclastic flows have ____ velocity and temperatures of ______

A
  • high

- 100 to 800 degrees C

38
Q

What is the most direct cause of death in eruptions?

A

pyroclastic flows

39
Q

lahars are hyperconcentrated __________, have _____ density, are highly _____, and can occur ________ an eruption

A
  • volcanic mudflows
  • high
  • erosive
  • during or after
40
Q

Landslides are caused by

A
  • magma intrusion
  • explosive eruption
  • gravitational collapse
  • earthquake
41
Q

tsunmis are responsible for _____ percent of volcano-related fatalities

A

25

42
Q

volcanic gases are directly responsible for ___ perfect and indirectly responsible for ___ percent of volcano-related fatalities

A
  • 3

- 40

43
Q

How do volcanic gases cause death?

A
  • crop destruction
  • starvation
  • disease
44
Q

Volcano monitoring methods

A
  • seismic
  • ground deormation
  • microgravity
  • geochemical
  • thermal
45
Q

We can prevent volcanic hazards by _____ lahars, _______ lava flows, and avoiding building in ______

A
  • canalizing
  • water and solidifying
  • high-risk zones
46
Q

The Nevado del Ruiz eruption was _____ but had a ______ death toll

A
  • small

- large

47
Q

the Mt. Pinatubo eruption was _____ but had a ______ death toll

A
  • large

- smaller

Earth Science (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions