Brainscape's Knowledge GenomeTM

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


See full index

AS Geography - Abbi > Hazards (Mostly Volcanic) > Flashcards

Hazards (Mostly Volcanic) Flashcards

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

What are five things that Natural Hazards have in common?

A
  1. No Warning
  2. Involuntary exposure in LICs
  3. Clear Origins
  4. Losses shortly afterwards
  5. Emergency response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What three ways do people perceive natural hazards?

A
  1. Fatalism
  2. Adaption
  3. Fear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the four parts of the disaster management cycle?

A
  1. Mitigation
  2. Response
  3. Recovery
  4. Preparedness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Give two strengths and two weaknesses of the disaster management cycle?

A

Strengths

  1. Evaluate Response
  2. Not place specific

Weaknesses

  1. No data
  2. Ignores Individuals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What evidence supports Seafloor Spreading?

A

The mirrored magnetism on either side of an ocean ridge.

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

What theory did Alfred Wegener suggest?

A

Continental Drift (Pangea - all, Laurasia- North, Gandwanaland - South)

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

Give three features of a hotspot.

A
  1. Stationary
  2. Thin Crust
  3. High heat flow (magma plume)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the six parts of the risk disc model?

A
  1. Disaster response
  2. Disaster recovery
  3. Mitigation
  4. Adaption to climate change
  5. Disaster preparedness
  6. Development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the lithosphere?

A

Rigid part of the mantle. Crust

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

What is the asthenosphere?

A

Semi-molten part of mantle.

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

How do constructive/ divergent plates move?

A

Apart.

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

How do destructive/convergent plates move?

A

Towards each other.

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

How do conservative plates move?

A

Side by side.

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

For each plate boundary are there: Earthquakes, Volcanoes or both?

A

Constructive: Both
Destructive: Both
Conservative: Earthquakes

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

What are the three types of destructive plate boundary?

A
  1. Oceanic/ Oceanic
  2. Oceanic/ Continental
  3. Continental/ Continental
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What landforms are found at Destructive plate boundaries?

A

Ocean trench : Oceanic/ Oceanic
Fold Mountain : all types possible
Island Arcs: Oceanic/ Oceanic

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

What landforms are found at Constructive plate boundaries?

A

Ocean Ridge: Oceanic/ Oceanic

Rift Valley: Continental/ Continental

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

What is a natural hazard?

A

Events that are seen as a threat to people and the built environment. Occur in the lithosphere, atmosphere and hydrosphere.

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

What is meant by fatalism in the context of hazards?

A

Cannot influence shape of outcome, nothing can be done.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is perception important in the context of hazards?

A

It will decide the course of action or the response from governments or organisations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why do people consciously put themselves at risk from natural hazards?

A
  • Lack of alternatives
  • Changing level of risk
  • Cost/ benefit
  • Perception
  • Unpredictable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What factors influence people’s perception of natural hazards?

A
  • Socio-economic status
  • level of education
  • occupation
  • religion, culture
  • Family status
  • past experience
  • personality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is community preparedness/ risk sharing?

A

Prearranged measures to reduce loss of life.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The distribution of a hazard through time is called….

A

Frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

The assessment of the size and impacts of a hazard event is known as the…

A

Magnitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is meant by the term resilience?

A

Ability to utilize resources to respond and recover.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is a primary hazard event?

A

Directly related to the hazard event e.g. lava flows & ash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a secondary hazard event?

A

Occur due to the occurance of a primary hazard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the differents layers of the Earth’s structure?

A

Inner core, Outer core, Mantle, crust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the two different layers of the mantle?

A

Lithosphere, Asthenosphere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the two layers of the crust?

A

Oceanic & Continental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How was the Earth formed?

A
  • Accretion
  • Gravitational compressions, radioactive decay
  • Heavier metal sinking, lighter rising
  • Temperature rise above 2000 C and layers formed as it cooled
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What evidence did Alfred Wegener use to support his theory?

A 
Geological evidence (glacial striations, rock sequences, continents fit together)
Biological evidence (fossil evidence- brachiopods, fossil remains of plants, mesosaurus in S America and S Africa)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What did Frederick Vine & Drummond Matthew add to the theory of continental drift?

A

Sea floor spreading. Supported by the evidence of mirrored magnetism on either side of an ocean ridge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What did John Tuzo Wilson add to the theory of continental drift?

A

The theory that plates move over fixed ‘hotspots’ in the mantle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are two reasons that the Earth’s core is so hot?

A
  • Primordial heat

- Radiogenic heat (radioactive decay)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a mid-ocean ridge?

A

Undersea line of volcanoes forming at constructive plate boundaries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is a rift valley?

A

Deep valley with steep sides, forming at constructive plate boundaries, caused by sinking land between fault lines e.g. African Rift Valley. Continental/continental.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is an ocean trench?

A

Deep valley where an oceanic plate is subducted at a destructive plate boundary, causing downwarping. E.g. Marianas trench

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is an island arc?

A

Volcanoes form on the oceanic plate, not subducting. E.g. Mariana islands.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are fold mountains?

A

Crumpling and uplifting of the less dense plate at destructive plate boundaries. E.g. Himalayas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the Benioff zone?

A

Area of high friction and heat between subducting and non-subducting. This melts the subducting plate and causes earthquakes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is a tectonic plate?

A

Part of lithosphere moving on top of the asthenosphere.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is a hotspot?

A

A small stationary area of the Earth’s crust with high heat flow due to a rising magma plume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is a magma plume?

A

A stationary area of high heat flow, that is formed due to intense radioactivity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is a seamount?

A

A seamount is an eroded extinct volcano that has sunk under the water due to erosion and subsidence.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Three types of hazard?

A
  • Geographical
  • Atmosphere
  • Hydrological
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Vulnerability in context of hazards

A

How susceptible the area is to damage and potential for loss

49
Q

Risk in context of hazards

A

Likelihood of harm

50
Q

Multi hazard environment

A

Place at risk of two or more different hazards that may interact

51
Q

Adaption in context of hazards

A

Living with hazards, by adjusting their living conditions

52
Q

Mitigation

A

Lessen severity of hazards

53
Q

Fatalism

A

Nothing can be done. Limited or no prevention measures against the hazard.

54
Q

Socio-economic status

A

Wealth determines how much control they have over the hazard damage & risk. Wealthy areas are more protected in ways poorer areas can’t afford.

55
Q

Level of education

A

If people are uneducated on hazards they aren’t aware of the risk or believe that they are unable to reduce risk.

56
Q

Religion

A

They believe that their god will deal with the hazard and therefore don’t mitigate.

57
Q

Past Experience

A

They are more prepared and feel like they know how to handle it as they expect it to be similar to past experience. May have a ‘lightning never strikes twice’ approach.

58
Q

Community Preparedness/ Risk Sharing

A

Prearranged collective methods to reduce loss of life.

59
Q

Integrated Risk Management

A

Social/ political/ economic factors of risk analysis. Decides acceptability of damage. Decides plan to minimise damage.

60
Q

The park model shows changes of ______ over time?

A

Quality of life

61
Q

Five stages of the Park Model

A
  • Pre disaster
  • Disruption
  • Relief
  • Reconstruction
  • Rehabilitation
62
Q

What does the Park Model tell us about a country’s disaster response?

A

Depth of curve- intensity of impacts
Steepness of upward curve - They were well prepared and immediate response was successful
Steepness of downward curve - Type of hazard (rapid or slow onset)

63
Q

Positive and negatives of Park Model

A

+

  • Compares effectiveness of recovery between events
  • Predict resources
  • Plan for future
  • No spacial variation
  • No quantitative data
  • Only single event on single area
  • Doesn’t show pre-onset mitigation
64
Q

Rehabilitation stage of park model

A

Solve longer term problems after immediate impacts are controlled

65
Q

Ability of individuals to withstand and recover from a disaster is known as…

A

Resilience

66
Q

Methods of prediction

A
  • Scientific Research
  • Tsunami Warning System
  • National Hurricane Centre (Florida)
67
Q

Factors that are needed to make prediction an effective management technique

A
  • Information must be accurate
  • Must be trustworthy
  • Information must be distributed
68
Q

Three ways people and organisations manage natural hazards

A
  • Prediction
  • Protection
  • Prevention
69
Q

Differences between oceanic and continental crust

A

Oceanic

  • More dense
  • Thinner (6-10 km thick)
  • Younger (less than 200 million years)
  • Basalt & SIMA

Continental

  • Less dense
  • Thicker (30-70 km thick)
  • Older (over 1500 million years)
  • Granite, SIAL
70
Q

Describe each layer of the earth

A

Inner core

  • Iron & nickel
  • Solid
  • Over 6000 C

Outer core

  • Iron & nickel
  • Liquid
  • 4000-5000 C

Mantle

  • SIAL & SIMA
  • Semi molten
  • 3000 C

Crust

  • SIAL & SIMA
  • Solid
71
Q

Process of convection currents in the asthenosphere

A
  • Hot spots in the Earth’s core cause thermal plumes in the asthenosphere
  • Hot magma rises as it is less dense and when it reaches the lithosphere, it moves sideways
  • This basal drag moves the plates
  • The magma cools becoming more dense and sinking
  • This is a continuous cycle
72
Q

Process of gravitational sliding at ocean ridges

A
  • Magma rises to the surface
  • This heats the surrounding rocks, creating a slope
  • As the new crust cools, gravity moves it, creating a downslope
  • There is a lot of pressure on the plates, causing them to move apart
73
Q

Process of slab pull at ocean trenches

A
  • Destructive oceanic plate subducts
  • Dense plate pulled down by gravity
  • Pulls the rest of the plate behind it
74
Q

Formation of ocean ridges

A
  • Plates diverge in oceanic areas
  • This creates fissures, which magma escapes through
  • Magma fills gaps, erupts onto the surface and cools as new land
75
Q

Formation of rift valleys

A
  • Plates diverge. Magma rising causes crust to fracture, forming fault lines
  • Crust between faults drops down, forming a rift valley
  • The crust here is thinner due to tension. Magma forces its way through these areas. These reach the surface to form volcanoes
76
Q

Formation at oceanic-continental destructive plate boundaries.

A
  • Oceanic plate subducts as it is more dense. Causes downwarping, forming a trench
  • Friction at benioff zone causes the subducting plate to melt
  • Magma rises through fissures in crust as it is less dense than surrounding asthenosphere. This creates composite volcanoes
  • Sediments crumple and uplift to form fold mountains
  • Plates can become stuck due to friction. Plates release seismic energy as they slip past each other.
77
Q

Formation at oceanic-oceanic destructive plate boundaries.

A
  • Denser plate subducted. Forms a deep ocean trench and triggers earthquakes & volcanic eruptions
  • Volcanic eruptions take place underwater
  • This creates volcanic island arcs
78
Q

Formation at continental-continental destructive plate boundaries.

A
  • Plates crumple & uplift as they are similar densities. Forms fold mountains
  • No volcanoes form as neither subducts. Pressure can cause earthquakes.
79
Q

Formation at conservative plate boundaries.

A
  • Plates move alongside each other in opposite directions or at different speeds.
  • Plates get stuck due to friction & pressure build up
  • Plates jerk past each other or crack, forming fault lines. This releases pressure, sending shockwaves through the crust in the form of earthquakes
80
Q

Three features of a hotspot

A
  • Stationary
  • Thin crust
  • High heat flow (plume)
81
Q

Formation of a hotspot

A
  • Intense radioactivity forms magma plume.
  • Plume reaches the asthenosphere. High heat & low pressure of plume melt the lithosphere above.
  • Lava breaks through, forming active volcanoes
  • Plume remains stationary but plate moves, creating chain of volcanoes. Volcano above hotspot is active but the remainder are extinct
  • Extinct volcanoes put pressure on crust which causes subsidence and erosion, creating seamounts
82
Q

Differences between shield & composite volcanoes

A

Shield

  • Wide base & sloping sides
  • Frequent & not explosive
  • Basaltic lava

Composite

  • Steep sides
  • Explosive & infrequent
  • Andesitic & rhyolitic lava
83
Q

Examples of hotspots

A
  • Reunion hotspot (deccan traps)

- Hawaii hotspot

84
Q

What is VEI?

A

Volcanic Explosivity Index

85
Q

What does VEI measure?

A
  • Volume of ejecta
  • Height of eruption column
  • Qualitative observations
86
Q

Criticisms of VEI

A
  • Doesn’t account for climate change
  • Doesn’t account for gas emissions
  • Considers all tephra the same
87
Q

Five ways volcanic eruptions vary

A
  • Magnitude
  • Frequency
  • Predictability
  • Regularity
  • Duration
88
Q

What is a super volcano?

A

An unusually large volcano with the potential to produce an eruption with major effects on global climate & ecosystems

89
Q

Tephra

A

Solid material of varying sizes (primary hazard)

90
Q

Pyroclastic flows (nuees ardentes)

A

Super heated, high velocity & density flows of gas and tephra which flows down the side of volcanoes (primary hazard)

91
Q

Lava flows

A

Melted down magma that flows down the side of the volcano. Speed depends on temperature, viscosity and steepness. (primary hazard)

92
Q

Volcanic gases

A

Carbon Dioxide, Sulphur Dioxide, Hydrogen Sulphide, Carbon Monoxide and Chlorine. (primary hazard)

93
Q

How does incidence affect level of management?

A

The more frequently an area experiences a hazard, the more it’s expected so more management is in place. These hazards also tend to be less intense so less large management.

94
Q

How does intensity affect level of management?

A

High intensity have worse affects and require more management.

95
Q

How does distribution affect level of management?

A

high hazard distribution have less management. Those living in those areas will be more adapted to the hazardous landscape.

96
Q

How does level of development affect level of management?

A

LICs are less able to afford management strategies and hazards are therefore more disastrous.

97
Q

How do multi hazard environments affect level of management?

A

Lack of money to manage multiple hazards so may lack management.

98
Q

Prediction in the context of hazards

A

Using scientific research to forecast when and where hazards will occur and to provide warnings

99
Q

Protection in the context of hazards

A

Protect people from the impact of the event by modifications to the built environment

100
Q

Examples of secondary volcanic hazards

A
  • Lahars
  • Flooding
  • Volcanic landslides
  • Tsunamis
  • Acid rain
  • Climate change
101
Q

Sea Floor Spreading

A

Theory that the ocean floor was created at mid-ocean ridges and has expanded due to volcanic activity. Plates must be destroyed somewhere to accommodate their size increase.

102
Q

Characteristics of basaltic lava

A
  • 45-55% silica content
  • 1050-1200 C
  • Low viscosity
  • Low gas content
  • Shield volcano
  • Constructive plate boundaries
  • Gentle, effusive explosion
103
Q

Characteristics of rhyolitic lava

A
  • 65-75% silica content
  • 650-800 C
  • High viscosity
  • High gas content
  • Composite volcano
  • Destructive plate boundary
  • Explosive, infrequent
  • Ash, rocks, gases and lava ejected
104
Q

Characteristics of andesitic lava

A
  • 800-1000 C
  • 55-65% silica content
  • Medium viscosity
  • Medium gas content
  • Composite volcano
  • Destructive plate boundary
  • Explosive, infrequent & short-lived
  • Ash, rocks, gases and lava ejected
105
Q

How are lahars formed?

A

melted ice & snow or heavy rainfall due to eruption, mixes with volcanic ash and forms mud flows.

106
Q

How are tsunamis formed?

A

Waves are generated by violent volcanic eruptions or pyroclastic flows/lahars displacing water. Often leads to much more widespread impacts than the explosion itself.

107
Q

How is acid rain formed?

A

The gases emitted by the volcano, such as sulphur, combine with atmospheric moisture.

108
Q

How does volcanic activity cause climate change?

A

Huge amounts of volcanic debri into the atmosphere can cause global temperature reduction.

109
Q

Impact of lahars (with case study)

A

1985, Nevado Del Ruiz, Colombia. 23,000 people killed Destruction of natural habitats, settlements. Economic benefits of lahar deposits. Can have impacts years into the future.

110
Q

Impact of tsunamis (with case study)

A

2018, Anak Krakatua volcano, Indonesia - landslide triggered a tsunami which killed 400 people. Widespread destruction.

111
Q

Impact of acid rain

A
  • Damages and kills trees
  • Leaches toxic metals from soil
  • kills fish stock and damages ecosystems
  • damages buildings and monuments by accelerating weathering
112
Q

Impact of climate change

A

Unusually cold weather. Crop failure and food shortages.

113
Q

How can the four volcanic hazard warning signs be predicted?

A

Sulphur/ radon gases: spider robots/ gas trapping bottles
Ground deformation: tiltmeter. gravity changes
Energy release: infrasound. seismometers
Surface temperature changes: thermal heat sensors

114
Q

Methods of preparedness to reduce volcanic hazard risk

A
  • Hazard mapping: plotting predicted levels of risk. People are less vulnerable as they are removed from high risk areas
  • Authorities limit access to hazardous areas and create evacuation routes.
  • Preparing emergency kits
  • Installing monitoring systems
  • Search and rescue teams
  • Educate residents on preparation measures
115
Q

Three things that affect speed of lava flow

A
  • Temperature (Higher temperatures flow further)
  • Viscosity (low viscosity flow further)
  • Steepness of slope (steeper slopes flow further)
116
Q

Methods of diverting lava flows

A
  • Creating earth trenches
  • Bombing lava tubes
  • Use of ice water/ cooling the lava
117
Q

How might people adapt to the risks of volcanic activity?

A
  • Strengthening buildings to reduce chance of collapse from ash on the roof
  • Capitalise on the opportunities of living near volcanoes e.g. farming fertile soils or tourism
118
Q

Primary impacts of volcanic activity

A
  • People killed and buildings destroyed by pyroclastic flows
  • Ash causes damage to agriculture
  • Flights suspended by ash
  • Death from volcanic gases
119
Q

Secondary impacts of volcanic activity

A
  • Acid rain acidifies ecosystems
  • Volcanic debris reflects sunlight and kills crops from cold winters
  • Flash floods from glaciers melting
  • Tsunamis due to volcanic landslides displacing water
  • Death from lahars

AS Geography - Abbi (16 decks)

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