Tectonics Flashcards

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1
Q

What is a tectonic hazard

A

a tectonic event that has the ability to cause harm onto people or property

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2
Q

What is a plate boundary

A

distinct zones at the edges of tectonic plates where earthquakes usually occur

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3
Q

What are intraplate regions

A

an area where intraplate earthquakes occur due to a build up of stress by continental rifting or its transfer from other regions

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4
Q

What is a divergent plate boundary

A

where plates move away from eachother

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5
Q

What is a conservative plate boundary

A

where plates slide past eachother

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6
Q

What is a convergent plate boundary

A

where the oceanic crust slides under the continental crust

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7
Q

What makes a volcano more explosive

A
  1. higher silica content
  2. high viscocity
  3. lower temperatures
  4. more gas
  5. water content
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8
Q

What are characteristics of the continental crust

A
  1. made of less dense rocks
  2. created at destructive plate boundaries
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9
Q

What are the characteristics of oceanic crust

A
  1. made of denser rocks
  2. formed at divergent plate boundaries
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10
Q

What is the lithosphere

A

the fusion of the crust and upper most solid mantle

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11
Q

What is the aesthenosphere

A

the ductile/rheid layer of the Earth that allows the plate to move

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12
Q

What is the mantle

A
  1. 82% of Earth’v volume (aesthenosphere to outer core)
  2. made of silicate rock rich in iron and magnesium
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13
Q

What is the core made up of

A
  1. mostly iron and nickel
  2. outer = liquid
  3. inner = solid
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13
Q

What are deep sea ocean trenches

A

the point where oceanic plates subduct beneath continental plates

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14
Q

What are fold mountains

A

when subduction causes mainly sedimentary rocks to warp and be pushed upwards from collisions

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15
Q

What is the benioff zone

A

the area where earthquakes occur

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16
Q

What is subduction

A

when one edge of a plate is force beneath another

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17
Q

What are mantle plumes

A

abnormally hot rocks which are moving up the Earth

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18
Q

What are hotspots

A

when mantle plumes breach the surface and spew lava

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19
Q

What do mantleplumes/hotspots create

A
  1. intraplate volcanoes
  2. island arcs
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20
Q

What is the proof of Alfred Wegners theory of continental drift

A
  1. plates are puzzle pieces and create Pangea
  2. continents broke away and drifted apart
  3. tropical fossils sound in Antartica
  4. glacial deposits in Brazil/tropical/desert areas
  5. rock layers matching in different countries
  6. fresh water fossils found across oceans
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21
Q

What is seafloor spreading

A

the divergent motion of oceanic plates and rise of balsatic magma to produce mid-ocean ridges

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22
Q

How does paleomagnetism prove seafloor spreading

A

magma locks in the Earth’s magnetic polarity, which shows changes in geology

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23
Q

What is slab pull

A
  1. when dense oceanic crust becomes heavier than the aesthenosphere and descends at subduction zones
  2. the weight of the sinking cooling plate causes a major pulling motion
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24
Q

What is ridge push

A
  1. when plates are hotter and less dense than their surroundings and rise
  2. form mid-ocean ridges
  3. slide sideways off high areas
  4. pushes plates infront of them
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25
Q

What is the modified Mercalli scale

A
  1. a measure of intensity
  2. based on the observations of people who experienced the event
  3. I-XII
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26
Q

What is the Moment Magnitude Scale

A
  1. a measure of the total energy released by an earthquake as soon as it occurs
  2. 1-10
  3. logarithmic
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27
Q

What is the Volcanic Explosivity Index

A
  1. a logarithmic scale that measures a volcanoes column height, volume of tephra released, and qualitative observations
  2. 0-8
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28
Q

What is the hypocentre/focus

A

where the stress is released

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29
Q

What is the epicentre

A

the point directly above the hypocentre

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30
Q

What are the characteristics of P-Waves

A
  1. fastest
  2. reach the surface first
  3. compressional waves
  4. travel through liquids and solids
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31
Q

What are the characteristics of S-Waves

A
  1. slower than P-waves
  2. only pass through solids
  3. lateral movements
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32
Q

What are the characteristics of L-Waves

A
  1. slowest
  2. cause the most damage
  3. high amplitude
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33
Q

Why does felsic magma contain more silica, allowing it to produce more explosive eruptions

A

form at convergent boundaries where continental and oceanic crust is melting

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34
Q

What are primary hazards

A

hazards that occur during the natural disaster

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35
Q

What are secondary hazards

A

hazards that occur after the natural disaster

36
Q

Secondary Hazard:Earthquake

What is liquefaaction

A

When ground shaking causes surface rocks to lose strength and become more liquid than solid

37
Q

Secondary Hazard:Earthquake

What is a landslide

A

when ground shaking places stress on the cliff slope causing a rapid downslope movement

38
Q

Secondary Hazard:Earthquake

What is a tsunami

A
  1. a series of large-waves caused by underwater volcanoes or earthquakes
  2. vertical displacement of the crust causes the water column to do the same
39
Q

Secondary Hazard:Earthquake

What is an avalanche

A

when ground shaking on the cliff slope causes the rapid downstream movement of large quantities of snow

40
Q

Secondary hazard:Earthquake

How are diseases caused by earthquakes

A

debris contaminates water sources allowing harmful pathogens to grow and spread

41
Q

Primary hazards:Volcanoes

What are lava flows

A

streams of lava erupted from the volcano

42
Q

Primary hazards:Volcanoes

What are pyrochlastic flows

A

a mixture of dense hot rock, lava, ash, and gases that are ejected at high speeds from the side of a volcano

43
Q

Primary hazards:Volcanoes

What is ash fall

A

small particles of rock and volcanic glass that lands after eruptions blast them into the air

44
Q

Primary hazards:Volcanoes

What is a gas eruption

A

When volcanic gases (water vapour, CO2, SO2) that were dissolved in magma are released into the atmosphere

45
Q

Secondary Hazards:Volcanoes

What are wildfires

A

Great fires caused by heat from a volcano

46
Q

Secondary Hazards:Volcanoes

What are lahars

A

hot masses of rock, mud, and water quickly that tarvel down the side of a volcano

47
Q

Secondary Hazards:Volcanoes

What are Jokulhlaups

A

heavy and sudden floods caused by the melting of now and ice

48
Q

Why does mafic magma contain less silica, allowing it to produce less explosive eruptions

A

formed at divergent boundaries where magma comes from the mantle, making them less viscous which allows highly explosive gas to escape

49
Q

What is a risk

A

the factors that lead to some individuals or groups becoming more vulnerable to a hazard

50
Q

What is vulnerability

A

all the factors that when combined make an individual or a group more susceptible to tectonic disasters

51
Q

What is the capacity to cope

A

refers to all the strengths, attributes, and resources available within a community to manage and reduce disaster risks

52
Q

What is resilience

A

the ability of a community to rehabilitate and reconstruct after disasters and return to a high quality of living standards

53
Q

What are root causes

A

fundamental characteristics of a place

54
Q

What are dynamic pressures

A

changes or deficits in a place, caused by root causes

55
Q

What are unsafe conditions

A

how hazardous a place is, result of root causes and dynamic pressures

56
Q

What are some examples of root causes

A
  1. limited access to power, infrastructure, resources
  2. dominant idologies, political systems, and economic systems
57
Q

What are some examples of dynamic pressures

A
  1. lack of training, local investment, press freedom, proper infrastructure
  2. rapid population change
  3. rapid urbanisation
  4. deforestation
58
Q

What are some examples of unsafe conditions

A
  1. physical environment
  2. local economy
  3. social relations
  4. public actions
59
Q

What is the Pressure & Release Model

A

a theory that states that a disaster is caused by a progression of vulnerability and a natural hazard

60
Q

What is governance

A

decision making

61
Q

How is governance used in relation to tectonic disasters

A
  1. planning regulations
  2. disaster preparedness and response
  3. financial management
  4. local to global scale
62
Q

What is involved in administrative governance

A
  1. implementation, recording, monitoring, and enforcement of policies
  2. land use planning
  3. creating and enforcing strict license schemes
62
Q

Who are the players involved in disaster governance

A
  1. governments
  2. local authorities
  3. NGOs
  4. IGOs
  5. businesses
63
Q

What is involved in economic governance

A
  1. control the country’s economic activities
  2. controls the realtionship with other countries
  3. controls the financial decisions
64
Q

What is involved in political governance

A
  1. creation of policies
  2. discussion of plans
  3. decide what to do before, during, and after a disaster
65
Q

Are we experiencing more disasters

A

no, they are staying at a constant rate

66
Q

why are disaster statistics unreliable

A
  1. can be misreported by the government
  2. greater inaccuracies (especially in developing countries)
  3. don’t account for post-disaster affects
67
Q

What are multiple hazard zones

A

a location where two or more geographical or hydrometerological hazards can occur at any point

68
Q

What is a tectonic mega-disaster

A

A large scale disaster on either spatial extent or in terms of economic/human impacts

69
Q

How has globalisation made tectonic mega-disasters more dangerous

A

efficiency of supply chains decrease

70
Q

What is the Just in Time economic model

A

when a company orders small shipments of raw material and products when it forcasts it will need it

71
Q

How are volcanoes predicted

A
  1. tiltmeters measure volcanic bulging (magma filling the chamber and SO2 increases)
  2. earthquake sensors measure mini-earthquakes and rumbling (as magma moves)
  3. cameras look for signs
72
Q

How are earthquakes forecasted

using probabilistic forecasting

A

monitor where an earthquake hasn’t occured in a while

73
Q

How can countries modify the loss of a tectonic hazard

A
  1. provide the poor aid
  2. provide insurance schemes for the rich
  3. use the aid of NGO’s effectively
  4. have effective search and rescue operations
74
Q

How can countries modify the vulnerability of a tectonic hazard

A
  1. have accurate prediction and warning systems
  2. educate the community on preparedness
  3. educate the community to change their behaviour to better cope with hazards
75
Q

How can countries modify the event of a tectonic hazard

A
  1. have greater control of the environment
  2. avoid hazardous areas through land use zoning
  3. create infrastructure with hazard-resistant design
76
Q

what is mitigation

A

attempting to reduce the effects of the event

77
Q

What is adaptation

A

conducting changes to minimise the harm of an event

78
Q

In the hazard management cycle what encompasses mitigation

A

building defences

79
Q

In the hazard management cycle what encompasses preparedness

A
  1. the education and training of the community
  2. having accurate and updated warning systems
  3. having emergency services and hazard shelters
80
Q

In the hazard management cycle what encompasses response

A
  1. having easy to access evacuation shelters
  2. having good emergency managemetn and govenance
81
Q

In the hazard management cycle what encompasses recovery

A

the rebuilding, restoring, and redesigning of the affected areas

82
Q

What are earthquake resistant designs

A

when buildings are designed in such a way that reduces collapsing

83
Q

What are examples of earthquake resistant designs

A
  1. cross-braces
  2. base insulators
  3. mass dampeners
  4. shinbashira
  5. shear walls
84
Q

How can enigneering solutions modify the event

A

building defences can prevent hazards from affecting a greater part of the population

85
Q

How can the diversion of lava flows or lahars modify the event

A

using barriers to divert these reduces damages and deflects danger to less vulnerable areas

86
Q

How can land use zoning modify the event

A

understanding where high-risk areas are so they aren’t built upon will mean there is nobody in vulnerable areas