Brainscape's Knowledge GenomeTM

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


See full index

IGCSE Geography > 2.1 Earthquakes and volcanoes > Flashcards

2.1 Earthquakes and volcanoes Flashcards

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

What is a ‘volcano’?

A

An opening in the Earth’s crust through which hot molten magma (lava), molten rock and ash are erupted onto the land.

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

Where are most volcanoes usually found?

A

Plate boundaries although there are some exceptions, or a hotspot.

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

What is a ‘hotspot’?

A

A relatively small area where magma rises through a continental or oceanic plate.

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

What is ‘magma’?

A

Molten materials inside the Earth’s interior.

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

What is ‘lava’?

A

When the molten material is ejected at the Earth’s surface through a volcano or a crack at the surface.

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

What is ‘chamber’?

A

The reservoir of magma located deep inside the volcano.

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

What is ‘crater’?

A

The depression at the top of a volcano following a volcanic eruption.

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

What is ‘vent’?

A

The channel which allows magma within the volcano to reach the surface in a volcanic eruption.

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

What is a ‘tectonic plate’?

A

The theory that the Earth’s outer shell is divided into several plates that glide over the mantle.

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

What are the two main types of volcanoes?

A
  • Strato-volcanoes (composite cone)

- Shield volcano

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

What is an ‘epicentre’?

A

The point on the Earth’s surface vertically above the focus of an earthquake

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

What is a ‘focus’?

A

The position within the Earth where an earthquake occurs.

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

What is the “Ring of Fire”?

A

A ring of volcanoes around the Pacific Ocean that result from subduction of oceanic plates beneath lighter continental plates.

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

Name the features of ‘strato-volcanoes’ + one example.

A
  • Narrow and steep
  • Explosive
  • Destructive
  • Silica lava
  • Only have one or a few vents to release lava
  • When the lava cools, these layers of lava become the sides
    e. g. Mount St Helens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name the features of ‘shield volcanoes’ + one example.

A
  • Wide and gentle slopes
  • Non-violent
  • Constructive
  • Basaltic
  • Occur at hot spots under the Earth’s surface
  • Erupt frequently, with lava spilling out from many vents
    e. g. Mauna Loa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name the three types of movements of plate boundaries.

A
  • Convergent
  • Divergent
  • Transform
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Convergent + example

A

when two plates are pushing toward each other

e.g. the boundary between the Eurasian plate and the Indian plate at the Himalayas

18
Q

Divergent + example

A

marks two plates that are moving apart from each other

e.g. the boundary between the African plate and the Arabian plate in the Red Sea

19
Q

Transform + example

A

occurs where the two plates slide past each other

e.g. the boundary between the Pacific Plate and the Australian plate, crossing New Zealand

20
Q

What are the four types of plate boundaries?

A
  • constructive plate boundary
  • destructive plate boundary
  • conservative plate boundary
  • collision plate boundary
21
Q

Constructive plate boundary + example

A
  • the two plates move apart from each other causing sea-floor spreading.
  • this causes new oceanic crust to form, creating mid-ocean ridges.
  • volcanic activity is common.
  • new land is created.
    e. g. North American plate and Pacific plate
22
Q

Destructive plate boundary + example

A
  • the oceanic crust moves towards the continental crust and sinks beneath it due to its greater density
  • this causes deep-sea trenches and island arcs to form
  • the continental crust is folded into fold mountains; volcanic activity is common
    e. g. Nazca plate and South American plate
23
Q

Conservative plate boundary + example

A
  • the two plates move pass each other in opposite directions, or same direction at different speed
  • no new land is created
  • no land is destroyed
    e. g. Pacific plate and North American plate
24
Q

Collision plate boundary + example

A
  • the continental crusts collide, as neither can sink they are folded up into fold mountains
    e. g. the Indian plate and Eurasian plate -> Himalayas
25
Q

Plate boundary

A

when two plates join

26
Q

Oceanic crust

A
  • found under the oceans
  • younger than continental
  • can be destroyed
  • can be made
  • denser
  • thinner
27
Q

Continental crust

A
  • found under land
  • older
  • thicker
  • less dense
  • can’t be made
  • can’t be destroyed
28
Q

How do convection currents work?

A
  • magma near the outer core is heated
  • as the magma expands it becomes less dense
  • the less dense magma then starts to rise towards the crust
  • as magma gets near the crust it begins to cool
  • the cooling magma becomes denser and begins to sink
  • the currents create friction with the crust above and causes it to move
29
Q

What are ‘earthquakes’?

A

any movement in the earth’s crust; they happen everyday but not felt by humans

30
Q

Aftershock

A

an earthquake that happens after the main earthquake. if the initial earthquake is strong, then the aftershock can be very strong

31
Q

Richter scale

A

measures the magnitude (strength of force) of earthquakes by a seismometer (on a seismograph)

32
Q

Mercalli scale

A

measures the intensity and effects of an earthquake or in other words the energy released

33
Q

The amount of damage done by an earthquake depends on

A
  • the amount of energy released
  • the depth of the focus
  • the density of the population
  • how the structures have been built
  • the type of bedrock - liquefaction
34
Q

Preparedness and vulnerability in MEDCs

A
  • hazard mapping and zonal planning
  • strict building codes against earthquake damage
  • the population would be educated about the hazards of earthquakes
  • hazards will be better monitored for predictions to inform the public
  • tents, blankets, food and water for anyone who lost their home
35
Q

Preparedness and vulnerability in LEDCs

A
  • don’t follow building codes
  • poorer -> less money for medical care and rescue teams
  • poorer transport and communication
  • services like electricity and water will take longer to fix
  • high population densities -> more people are affected
  • less money spent on prediction methods
36
Q

Short-term effects of earthquakes

A
  • death
  • injury
  • panic and fear
  • infrastructure damage
  • secondary hazards
37
Q

Long-term effects of earthquakes

A
  • homelessness
  • unemployment
  • dependency
  • disease
  • post traumatic stress disorder
  • rebuilding costs
38
Q

Why do people live in tectonic active locations?

A
  • poverty
  • inertia
  • infrequency
  • overpopulation
  • building design
  • education and preparation
  • economic opportunities
39
Q

Why do people choose to live near volcanoes?

A
  • their beauty
  • minerals
  • geothermal potential
  • tourism
  • hot springs near volcanoes
  • poverty
  • home
  • shortage of space
  • fertile land for agriculture
40
Q

Name a volcano where people choose to live near.

A

Mount St Helens - Washington, USA

why?

  • its natural beauty
  • home to people who like the outdoors
  • tourist destination because of its beauty
  • a good spot for fishing
  • it is well monitored, so people feel safe living near it
  • most would not leave because they are either scientists studying the volcano or residents who couldn’t bring themselves to leave their homes
41
Q

Name a volcano eruption.

A

Mount St Helens - Washington, USA

  • located in Washington, USA
  • sits on a destructive plate boundary where the Pacific plate and the Juan de Fuca plate subducts under the North American plate

Causes:
- been dormant for nearly 120 years until 18th may 1980, a 5.0 earthquake triggered a huge landslide and pyroclastic flow

Effects:

  • the pyroclastic flow traveled for 25km and flattened everything on its path
  • around 7000 animals died, and every tree within 30km of the volcano
  • 63 people died
  • a reduction of touristry and a total of £100mill damage to crops and machinery
  • destruction of 250 homes, 47 bridges, 15 miles of railways and 185 miles of highway
  • ash, steam and debris were sent to about 60,000 feet

solutions:
- temporary shelter were sent almost immediately by the US government
- 198 lives were saved
- money sent out by the government

42
Q

Name an earthquake + its causes + effects + solutions.

A

Christchurch earthquake

Causes

  • 22/02/2011
  • an earthquake of 7.1 magnitude and an aftershock of 6.3 magnitude on the Richter scale

Effects

  • 184 people died and 164 people were severely injured
  • people were trying to get in touch with family and friends, which caused roads and cell phone lines to be jammed
  • up to 10,000 buildings were damaged ad 10,000 needed to be demolished
  • water and sewage pipes were damaged
  • liquefaction

Solutions:

  • groups from different areas come to help (volunteers) by bringing food
  • rescue teams from all over the world came to supply essentials like bottled water, toilets etc.
  • national emergency was declared.

IGCSE Geography (19 decks)

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