Brainscape's Knowledge GenomeTM

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


See full index

*Geography* > Volcanoes > Flashcards

Volcanoes Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

Active volcano

A

Erupts regularly/likely to erupt soon
Mount Etna

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

Dormant volcano

A

Hasn’t erupted in recent history but is likely to erupt again Mnt Kilimanjaro

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

Extinct volcano

A

Hasn’t erupted in recent history + isn’t expected to erupt again
Mount Slemish

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

Acidic lava

A

Convergent boundaries
High silica content
800 C
High viscosity - moves slowly
Cools hard + fast
Gasses trapped - violent explosion
Forms steep sided slopes

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

Basic lava

A

Divergent boundaries
Low silica content
1,200 C
Low viscosity- moves quick
Cools + hardens slowly
Gases escape - gentle eruption
Forms gentle slopes

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

Tephra

A

Ash, dust + rock fragments emitted into the atmosphere

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

When tephra flows down the slopes of a volcano it is known as…

A

pyroclast

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

Pyroclastic flows

A

Can reach 500km/h + 1,000km
Power of the explosion crushes rocks in the vent. The pulverised rock + ash form air bubbles. Pyroclast can kill post eruption

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

Gases emitted in volcanic eruption

A

Carbon dioxide + sulfur

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

Oceanic-oceanic collision

A

Volcanic island eg. Philippines

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

Oceanic-continental collision

A

volacanic arcs eg. Cotapaxi (nazca subducts) in Ecuador

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

Divergent

A

Magma rises through fissures, no crust melting, gasses released eg. Mid Antlantic Ridge

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

Hotspots

A

away from boundaries, usually oceanic. Areas where the mantle is hotter, so it melts through the plate to form a volcano. Fixed point in the mantle, crust moves over it, oldest island = furthest away. Eg. Hawaiian islands

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

Composite cones /stratovolcanoes

A

convergent boundaries.
Explosive eruptions => alternating layers of acidic lava and pyroclastic material.
E.g. Mount St. Helens

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

Cinder cones

A

Smallest/most common type of volcano.
Made from pyroclastic material
Steep sides and a wide crater.
1 eruption => destroys their structure.

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

Calderas

A

Formed when composite cones explode violently.
Eruption factures rock => rock collapses in magma chamber => forms depression.
eg Yellowstone w 75 km caldera

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

Shield volcanoes

A

Form at divergent boundaries or over hotspots from gentle eruptions of basic lava
Volcano base >100 km diameter.
E.g. Mauna Loa and Mauna Kea, Hawaii

18
Q

Lava plateau

A

Formed when basic lava releases to surface from fissure eruptions + flows over a large area before cooling/solidifying.
Repeated eruptions => build-up layer by layer

19
Q

Antrim Derry plateau

A

60 million years old North American+ Eurasian diverged, fissures formed, large lava flows continued for 2 million years forming a 1.8km thick plateau, lava cooled+contracted, into hexagonal basalt columns, e.g. the Giant’s Causeway, Co. Antrim.

20
Q

Batholiths

A

during periods of fold mountain building magma rises through the crust, melts surrounding layers of rock => pocket underneath the new fold mountains, magma cools to granite over millions of years.
> 100 km2 w thin cover of metamorphic rock

21
Q

Leinster batholith

A

The Leinster Batholith> 1,500 km² 400 million years old
North American and Eurasian plates collided.
Thin layer of metamorphic rock protects granite from erosion, e.g. the Sugarloaf Mountain in Co. Wicklow is protected by quartzite

22
Q

Sills

A

Magma forces through layers of sedimentary rock, cools slowly to form horizontal layer of granite.

23
Q

Dykes

A

Magma forces through layers of sedimentary rock, cools slowly to form thin vertical layer of granite.

24
Q

Laccoliths

A

Magma forces through layers of sedimentary rock, pressure forces rock to bulge upwards, magma cools to form small, dome-shaped layer of granite.

25
Q

Lopoliths

A

Magma forces through layers of sedimentary rock, pressure forces rock to bulge upwards, magma cools to form small, dome-shaped layer of granite.

26
Q

Predicting volcanic activity

A

Gas emmisions - carbon dioxide + sulfur dioxide emissions
Ground deformation - Electronic Distance Meters (EDMS) and tiltmeters
Seismic activity - seismographs < 20 km radius
Rock temp

27
Q

List pros of volcanic eruptions

A

Fertile soil
Tourism
Geothermal energy

28
Q

Creation of fertile soil

A

most fertile in the world
basalt breaks down => nutrient-rich soil suitable
survival of 1 mill within 30 km of Mount Merapi, Idonesia + majority of rice

29
Q

Tourism - Iceland + mnt ST.Helens

A

42% Iceland’s income
<Tourism=< employment
Sightseeing eg. Blue lagoon, pompeii, mnt St. Helens new roads

30
Q

Geothermal energy - how it works

A

Magma heats igneous rock which heats the groundwater (10% Iceland = glacier)
Wells drilled + hot water pumped out decompresses at surface => steam + is piped to power station through a turbine => electricity

31
Q

Geothermal energy - positive results

A

30% of Icelands energy
40% less fossil fuels
heats greenhouses -self sufficient-no air miles

32
Q

Nelvado del Ruiz death count

A

Lahar killed 23,00 of Armero’s 28,700 population

33
Q

Why was Armero’s death count so high

A

Officials ignored reports
Red Cross called off search
Officials said it was safe to return

34
Q

Disruption to air travel

A

E15

35
Q

How high did ash go in E15

A

Ash 9.5 km into sky

36
Q

E-15 no fly zone

A

5 week no fly zone for North Europe

37
Q

E15 how many passengers grounded

A

10 mill passengers grounded

38
Q

How do volcanoes disrupt weather patterns

A

Thick ash clouds change weather patterns
Ash blocks out the sun’s rays => global reduction in temperatures

39
Q

Disrupted weather patterns example

A

Krakatoa 1883, glopal temp dropped 1.2C + famine in Russia

40
Q

How long did lava flow for Antrim Derry Plateau

A

2 million years

41
Q

How thick was the Antrim Derry plateau

A

1.8 km thick

*Geography* (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions