3.1.5.1 The concept of hazard in a geographical context Flashcards
Plate tectonics, Volcanic hazards,Seismic hazards,Storm hazards,Fires in nature (131 cards)
1
Q
What is a hazard
A
A potential to threat human life and property
2
Q
What are the 3 major types of hazard
A
Geophysical - caused by land processes eg volcanoes - majorly tectonics
Atomospheric - eg wildfires caused by weather
Hydrological - caused by water bodies and movement eg flooding
3
Q
What is perception
A
People have different viewpoints of how dangerous a hazard will be what risk they pose
Dependent on lifestyle, economic, cultural factors
4
Q
What is prediction
A
Using past events in order to know when a hazard will take place
5
Q
What is adaptation
A
Attempting to live with hazards by adjusting lifestyle choice
6
Q
Mitigation
A
Strategies carried out to lessen severity of hazard
7
Q
Management
A
Strategies to reduce hazards effects
8
Q
What is the Park model and what is the 4 bottom axis
A
Graphical representation of steps carried out in hazard recovery
-can be used in comparing hazardous events (eg hazardous event in LIC will have longer recovery time than HIC)
steepness of curve shows how quickly an area deteriorates and recovers
depth of the curve shows the scale of the disaster (ie. lower the curve, lower the quality of life)
pre- disaster
Relief
Rehabilitation
Reconstruction
9
Q
What is stage 1 - Relief (Parks model)
A
(hours-days)
- immediate local response - medical aid, search and rescue
- immediate appeal for foreign aid- the beginning of the global response
10
Q
What is stage 2- rehabilitation (parks model)
A
focuses on the longer-term restoration of services and infrastructure, including setting up temporary schools and shelters, following a hazard event
This stage includes setting up temporary schools, shelters, and other essential facilities to support the affected population.
11
Q
Hazards caused by volcanoes
A
Lava flows
Lahars(mudflows) - caused by melting ice at high latitudes
Floods- melting ice
Tephra - why rock ejected from volcano
Toxic gasses - released during eruptions
Acid rain - cause by sulfur dioxide released into atmosphere
Pyrocoastic flows - clouds of burning hot ash and gas that collapse down volcano at high speeds
12
Q
Tsunami
A
Cause when water is displaced from plates moving underwater, creating a large wave
13
Q
Liquifactuon
A
When soul is saturated , vibrations of earth cause it to act like liquid . Soil becomes weak
14
Q
Storm surge
A
Large rises in sea level - low pressure and Hugh winds
15
Q
What is a natural hazard
A
caused by natural processes
16
Q
What is vulnerability
A
how susceptible a population is to the damage caused by a hazard
17
Q
Impacts of hazards
A
Hazards can have significant impact while they are occurring and often need an emergcancy response
impacts can also go on for a long time after the hazard has passed
18
Q
How do circumstances of people affect their perception of hazards
A
people view hazards in different ways:
some will believe that they will never experience a hazard
some adapt their lifestyle to minimise risk
and some accept hazards as being beyond their control
19
Q
There are many responses to hazards that individuals and the gov. may take to try reduce vulnerability and its impacts
how would they do this?
A
people may try to prevent a hazard for example;
building flood defences.
people may try to mitigate impacts by protection and adaptation
gov may coordinate response to a hazard to manage effectively
20
Q
How can level of development affect how well a country manage hazards affectively
A
lack of wealth and technology
can lead to lack of education of hazards and how to stay safe and may not get warnings on phones etc
21
Q
Strengths of the park model
A
shows how responses progress during a disaster which may help learners predict what resources will be needed for each stage,
also helps planners prepare for future hazard
22
Q
State the four phases in the hazard management cycle
(mprr)
A
mitigation
preparedness
response
recovery
23
Q
What are the four phases in the hazard management cycle (describe)
A
Mitigation- aims to minimise impact of future disasters
preparedness- about planning how to respond to hazard
response- how people react when a disasters occurs
recovery- about getting the affected area back to normal
24
Q
The inner and outer core contain lots of ….?
A
iron and nicklel
25
The inner core is a
solid ball
26
the outer core is
semi- molten
iron/nickel
27
What type of crust is thicker continential or oceanic?
continental is thicker at 30-70km but is less dense than
oceanic crust which is thinner (6-10km) but more dense
28
What is the earths main internal source of energy
some of the heat energy is leftover from when the earth formed and some is left over from radioactive decay of elements such as uranium
29
What are the theories of how tectonic plates move
convection currents
ridge push
slab pull
30
How do convection currents move tectonic plates?
The core is very hot and lower parts of the asthenosphere heat up and slowly rise
as they move towards the top of asthenosphere they cool down, become dense and slowly sink
the circular movements of the semi molten rock create drag on base of tectonic plate causing them to move
31
How does slab pull move tectonic plates
at destructive plate margins
denser crust is forced under less dense crust
Slab pull is the pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight. The theory is that because the oceanic plate is denser than the hotter mantle beneath it, this contrast in density causes the plate to sink into the mantle.
32
How does ridge push move tectonic plates- extended
at **constructive plate margin**- magma rises to surface and **forms a new crust.**
This **heats** the **surrounding rocks** which expand and rise above the surface of the surrounding rocks forming a slope
as the new crust cools and becomes denser- gravity causes the denser rock to move down slope away from plate margins
this puts pressure on plate margins- causing them to move apart
33
What is seafloor spreading
as tectonic plates diverge, magma rises up to fill in the gap created- this then cools to form new crust
over time the new crust is dragged apart to form more new crust
whe this happens at a plate margin under the sea the plate margin gets wider
34
what does seafloor spreading create
mid ocean ridges
35
3 types of plate margins
constructive, destructive and conservative
36
what type of plate margins do volcanoes occur?
constructive and destructuve
37
Economic factors that influence perceptions of hazards
-quality of housing and infrastructure is likely to be higher in wealthier areas- this may mean that people feel safer
- increased spending and preparation and prediction- this may mean that people are more aware of the risks and are able to evacuate
-more investment in education- this may mean that people understand the potential dangers and are more likely to take action to minimise risk
38
Cultural factors that influence perception os hazards
-cultural values and beliefs may affect whether people trust scientific and government officials- this may mean they underestimate the risk
-some cultures believe that hazards are an act of god- may mean they dont wan to evacuate
people who have previously experienced a hazard may be more fearful- may mean they are more prepared
39
What type of landforms are formed at destructive - continental/ continental plates
40
What type of landform are formed at destructive plate boundaries - oceanic/oceanic
41
What landforms are formed at destructive plate boundaries- continental / oceanic
42
What type of landforms are formed at conservative plate boundaries
43
What type of landforms are formed at constructive plate boundaries - oceanic / oceanic
44
What type of landforms are formed at constructive plate boundaries- continental/ continental
45
What is the incidence
Frequency of a hazard
46
What is intensity
the power of a hazard - ie how strong it is
47
what is magnitude of a hazard
the size of the hazard, usually this is how a hazard's intensity is measured
48
What is the distribution of a hazard
where hazards occur
49
How does level of development affect response to hazards
economic development will affect how a place can respond to a hazard,
so a hazard of the same magnitude may have very different effects in two places of contrasting levels of development
50
What is perception
people different viewpoints of how dangerous hazards are and what risk they pose.
51
What are preceptions dependent on
lifestyle factors- such as economic and cultural facors
eg a wealthy person- less likley to view hazard as dangerous as they have money to respond to it
52
What is fatalism
the viewpoint that hazards are uncontrollable natural events, and any losses should be accapted as there is nothing that can be done to stop them
53
What is risk sharing
a form of community preparedness, whereby the community shres the risk posed by a natural hazard and invests collectively to mitigate the impacts of future hazards
54
Continental and oceanic- destructive plate boundary
how does it occur
-denser oceanic plate subducts below continental
- the plate subducting leaves a deep ocean trench
- built up pressure from the melting plate cause explosive volcanoes bursting through the continental plate
55
What happens at Oceanic and oceanic crust - destructive plate boundary
- Heavier plate subducts leaving an ocean trench
- built up pressure causes underwater volcanoes bursting throuht the oceanic plate
- lava cools and creates new land called **island arcs**
56
Continental and continental - destructive plate boundary
-both plates are not as dense as oceanic so lots of pressure builds
-ancient oceanic crust is subducted slighlty, but there is no subduction of continental crust
- pile up of continental crust on top of lithosphere due to pressure between plates
- Fold mountains formed fom piles of continenal crust
57
What happens at Oceanic and oceanic- constructive plate boundary
**-magma rises inbetween the gap** left by the two plates seperating, **forming new land when it cools**
-**less explosive underwater volcanoes formed** as magma rises
-new land roming on the ocean floor by lava filling the gaps is known as **sea floor spreading**
58
Continental to continental- constructive plate boundary
-any land in the middle of the seperation is forced apart, causing a rift valley
-volcanoes form where the magma rises
-eventually the gap will most likely fill with water and seperate from the main island
59
Forces influencing how convergent boundaries occur- RIDGE PUSH
Ridge push- the slope created when plates move apart has gravity acting upon it as it has a higher elevation
60
Forces infuencing how convergent boundaries occur- Slab pull
When a plate subducts, the plate sinking into the mantle pulls the rest of the plate (slab0 with it, causing further subduction
61
What happens at a conservitive plate boundary
parralel plates move in different directions or at different speeds
no plates are destroyed so no landforms are created
62
What are hotspots
**Areas of volcanic activity that are not related to plate boundaries**
Hot magma plumes from the manta rise and burn through weaker parts of the crust.
This can create volcanoes and islands
The plume stays in the same place but the plate continue to move, which sometimes causes a chain of islands (such as Hawaii)
63
Spatial distribution of volcanic hazards
Along constructive or destructive plate boundaries or located on hotspots
64
How to measure the maginitude of a volcano
Vulcanicity is measured using the Volcanic Explosivity Index.
The more powerful- the more explosive
65
Frequency of volcanic hazards
Volcanoes are classed as either active, dormant or extinct.
Estimated 50-60 volcanoes erupt each month
66
Regularity of volcanic activty
Eruptions are regular in that the eruption on each type of boundary are similar
(eg eruptions on destructive boundaries will regularly be more explosive than at constructuve boundaries)
however some can be irregular and not fit patterns
67
Predictabilty of volcanic eruptions
Regularity of eruptions can help estimate when eruptions willl take place
Seismic activty, gases releasing can all indicate an imminent eruption
NO DEFINITE way to predict volcanic eruption
68
What types of hazards are causes by volcanoes
Lava flows
Lahars
Floods
Tephra
Toxic gasses
acid rain
Nuees aredentes/ pyroclastic flow
69
What are lahars and reason for them
(mudflows)
usually caused by melting ice at high latitudes
70
What is tephra
any type of rock that is ejected by a volcano
71
What are Nuees ardentes/ pyroclastic flows
clouds of burning hot ash and gas that collapses down a volcano at high speeds
72
Primary and secondary effects of volcanic hazard-
Environmental
-PRIMARY
ecosystems damaged through various volcanic hazards
-wildlife killed
SECONDARY
-water acidified by acid rain
-gases contribute to greenhouse effect (global warming
73
Primary effects and secondary of volcanic hazard-
Economic
PRIMARY-
Businesses and industries destroyed or disrupted
SECONDARY-
Jobs lost
-profit form tourism lost
74
Primary
and secondary effects of volcanic hazard-
Social
PRIMARY
-people killed
-homes destroyed
SECONDARY
-fires can start
-trauma
homelessness
respiratory diseases
75
Primary
and secondary effects of volcanic hazard-
Poltical
PRIMARY
-government buildings disrupted or damaged
SECONDARY
-conflicts concerning govt. response eg food shortages insurance etc
76
Management to volcanic hazards
PREVENTION
AND
PREPARDENESS
Prevention- cant be prevented, only the risk to people can be prevented (eg not building near volcanoes)
Preparedness- monitoring increases notice of eruptions- warnings can be given out,
education on what to do- protects people
evacuation procesdures
training response teams
77
Management to volcanic hazards
MITIGATION
AND
ADAPTATION
Mitigation
-direct intervention eg concreate blocksto steer lava away from areas at risk
-strenghten buildings
-evacuation zones
-mitigating health effects by having emergancy services, aid and rescue
ADAPTATION
-capitalise on opportunities such as tourism
78
Spatial distribution of seismic hazards
along ALL BOUNDARIES
79
how is Magnitude of seismic hazards measured
Seismicity is measured using the RICHTER SCALE- measure of the strength of seismic waves
Mercalli scale also used- measures rate of destruction caused
80
Frequency of seimsic hazards
earthquakes are frequent around the world and occur every day
Hundreds of smaller magnitude earthquakes that cannot be felt by humans occur everyday
- but larger ones are less frequent
81
Regularity of seismic hazards
earthquakes follow no pattern and are random so there is irregularity between events
82
Predictability of seismic hazards
almost impossible to predict
Microquakes may give some indication but the magnitude cannot be predicted as how strong they are is random
83
Hazards caused by seismic events
Shockwaves
Tsunamis
Liquefaction
84
What are shockwaves
(seismic waves) - energy released from the sudden jolt that vibrates through the ground
85
What are Tsunamis
Caused when water is displaced from plates moving underwater, creating a large wave
86
What is liqefaction
when soil is saturated, the vibrations of an earthquake cause it to act like a liquid.
soil becomes weaker and more likely to subside when it has a large weight on it
Avalanches and landslides
87
Primary & secondary effects of seismic hazards- environmental
PRIMARY
Loss of ecosystems
-liquefaction
Pollution:
SECONDARY
-radioactive materials and other dangerous substances leaked from power plants
-saltwater from tsumanis flood fresh water ecosystems
-soil salinisation
88
Primary & secondary effects of seismic hazards- economic
Primary
- businesses destroyed
Secondary
-economic decline as businesses are destroyed
-high cost of rebuilding and insurance payout
-sources of income lost
89
Primary & secondary effects of seismic hazards- social
primary-
-buildings collapse
-injury/dealth
secondary
-gas pipes rupture- starting fires which can kill
-water supplies contaminated- spreading disease
Tsunamis- lead to damaging floods
90
Primary & secondary effects of seismic hazards- political
PRIMARY
-government buildings destroyed
SECONDARY-
-political unrest from food or water shortages
-can be initial chaos and lawelessness (eg looting)
91
RESPONSE AND RISK MANAGEMENT TO SEISMIC HAZARDS- prevention
**majority of seismic hazards cannot be prevented**- eg earthquakes and tsunamis
liquefaction of soils can be prevented through soil stabilisation
92
RESPONSE AND RISK MANAGEMENT TO SEISMIC HAZARDS- preparedness
earthquake prone areas such as japan have extensive awareness strategies and education im place - eg in schools Drop, cover, hold on.
earthquake and tsunami warnings systems
evacuation plans and training
93
RESPONSE AND RISK MANAGEMENT TO SEISMIC HAZARDS- mitigation
search and rescue, immediate emergency aid, evacuation (short term)
demolishing older, unsafe buildings
Tsunami wave breaks and sea walls
94
RESPONSE AND RISK MANAGEMENT TO SEISMIC HAZARDS- Adaptation
-Move away from at risk areas
-capitalise on opportunites, such as tourism
-insurance if living areas of risk
-changing lifestyle choices- eg moving valuabel items so they dont fall
-building speically desinged earthquake proof buildings
95
What is a tropical storm
a low pressure, spinning storm with high winds and torrential rain
96
Condtions for a storm to form
Temperature- ocean temp 26-27*C
rotation: forms around equator but no less then 5 dgerees on either side
air pressure- must be in areas of unstable air pressure- usually where areas of high pressure and low pressure meet (convergence) - so that warm air rises more steadilu and the clouds form
97
Spatial distribution of tropical cyclones
98
How is the Magnitude of tropical cyclones measured
Measured on the Saffir-simpson scale (1-5) based on windspeed and thus the power of the storm
99
Frequency of tropical storms
Northern-hemisphere from JUNE-NOVEMBER
Southern hemisphere- november to april
100
Regularity of tropical storms
are irregular because although they occur in same areas, their path does not follow a set routinen- route taken is dependant on the storm and climatic conditions
101
Predictability of tropical storms
form far away from land meaning satelite tracking of cloud formations and movement can occur and general route can be predicted
102
Hazards caused by tropical storms
high winds- over 300km/h
flooding- due to heavy rain and storm surges
landslides- soil heavy
storm surges- large rise in sea levels
103
Primary and secondary effect of tropical storms- environmental
PRIMARY
-beaches eroded
-coastal habitats such as coral reefs destroyed
Secondary
-river flooding- salt water contamination
-animals displaced
104
Primary and secondary effect of tropical storms- economic
PRIMARY
-businesses destroyed
-agricultural land damaged
Secondary
-high cost of rebuilding and insurance payout
-sources of income lost
-economic decline
105
Primary and secondary effect of tropical storms- social
Primary
- drowning
- -debris
- injury
- buildings destroyed
Secondary
-homelessness
poluted water supply- spread disease
-foodshortages- damaged by land
106
Primary and secondary effect of tropical storms- political
primary
-govt. buildings destroyed
secondary
- issues paying back international aid
- pressure for govt to do more about global warming
107
RESPONSE AND RISK TO MANAGEMENT TO TROPICAL STORM- prevention
cannot be avoided- however trying to mitigate climate change could prevent higher category storms
108
RESPONSE AND RISK TO MANAGEMENT TO TROPICAL STORM- preparedness
awareness through education
evacuation plans
satelite image tracking
storm warning and tv broadcasts
109
RESPONSE AND RISK TO MANAGEMENT TO TROPICAL STORM- mitigation
search and rescue, immediate emergancy aid etc
strengthing homes
clearing loose debris before storms
110
RESPONSE AND RISK TO MANAGEMENT TO TROPICAL STORM- adaptation
move away from area at risk
deisgn buildings to withstand high winds and flood damage
flood defenses such as houses on stilts, coastal walls etc
111
What is a wildfirw
A large, uncontrolled fire that quickly spreads through vegetation
112
Conditions favouring intense wildfires- vegetation type
Thick, close together vegetation allows fires to spread quickly and easily.
Trees and thick bushes lead to more intense wildfires
Grasslands do not burn as intensely.
Vegetatiion with flammable oils- like eucalyptus- causes more intense fires also.
113
Conditions favouring intense wildfires- fuel characteristics
Vegetation should be dry to allow it to catch
Finer vegetation causes fires to spread quicker, but larger
Thicker forms of vegetation burns for longer and more intensely
114
Conitions favouring intense wildfires- climate and recent weather
Must be in a climate that has **enough rainfall to have sufficient plant growth**, but considerable dry spells and droughts to dry out the fuel
Areas with **dry seasons** such as California allow for intense wildfires
**Wind** also causes fires to **spread quicker**
**Recent temperature increases** have caused an increase in the number of wildfires
115
What is the behaviour of wildfires
fires spread quickly on HILLS as heat rises.
Fires can also 'jump' acorss rivers and inmto areas due to lit debris which causes it to spread
116
Causes of wildfires
Can be NATURALLY or HUMANS
Humans may start fires accidentaly or through arson- eg lit cigarets, BBQs, train lines or agriculture
Natural causes include, volcanoes and lightning
117
Primary and secondary environmental effects of wildfires
Primary
- air pollution
- water pollution
- habitats destroyed in fire
- toxic gases released in burning
Secondary
- removing invasive species and stimuklating seed germination
- migration patterns of animals affected
- increased CO2 from fires- heighten greenhouse effect
118
Primary and secondary economic effects of wildfires
Primary
- businessess destoyed
- agricultural land damaged
- cost of fighting fires (eg firefighters water etc)
Secondary
- high cost of rebuilding and insurance payout
- sources of income lost
- Discouraging visitors, losing tourism sector
- planes cancelled
119
Primary and secondary social effects of wildfires
Primary
- people killled or injured
- homes destroyed
- people go missing during evacuations
Secondary
- homelessness
- food shortages
- health problems such as asthma from smoke inhalation
120
Primary and secondary political effects of wildfires
Primary
- govt. buildings destroyed
Secondary
- borrowing money for international aid
- pressure for govt to do more about global warming due to increased frequency
121
Response and risk management to wildfire hazards- prevention
Cannot be avoided overall
however can prevent some human-caused wildfires through awareness
122
Response and risk management to wildfire hazards- preparedness
public awareness about why wildfires start (eg smokey bear campaign)
evacuation plans and training
sateite image tracking to manage the areas at risk
red flag wrning systems so people know areas at risk
123
Response and risk management to wildfire hazards- mitigation
search and resuce, immediate emergency aid, evacuation (short term)
removing flammable material such as dead leaves
spraying water and fire retardent onto risk areas
building materials that will not releaase toxic chemicals into the atmostphere
124
Response and risk management to wildfire hazards- adaptation
move away from area at risk
fire breaks (gaps in trees) to stop fires spreading
reducing carbon footprint to lower CO2 emmissons to lower frequency
insurance to cover damage
125
Alberta wildfires 2016- facts and causes
Mass evacuation
-**90,000 residents** of Fort McMurrary fled
Nickname **"the beast"**
**Cause**: unknown initial ignition but dry contions, strong winds and high temperatures worsened fires
- dry conditions due to El Nino- caused low precipitation and warm weather
size- **600,000 hectares** (about size of greater london
126
Primary effects of Alberta wildires 2016
***Mass evacuation***
90,000 evacuated
highway 63 became gridlocked
**Infastructure damage**
2,400 buildings destroyed
electricity supply disruoted for weeks
**Environemtnal impacts**
released tons of CO2
Toxic ash contaminated rivers and lakes
**Economic losses**
$9 billion in damages- Canadas costliest disaster
oil industry shut down for weeks- losing over $1 billion in production
127
Secondary effects of Alberta wildfires 2016
**Air pollution & health issues ***
- smoke spread as far as the US and Europe, causing poor air quality
- increased respiratory illnesses like asthma
***Economic disruption ***
- thousands lost jobs as oil production halted (Fort McMurrary is an oil hub)
-insurance claims his $3.58 billion
**Psycholpgical & social impacts**
- many suffered PTSD, anxiety and depression
- community displacement led to long-term stress
**Environmental recovery**
- fire sterilised soil- delaying regrowth
- wildlife populations suffered due to habitat loss
128
Immediate responses for the Alberta Wildfires 2016
mass evacuation- (90,000)
no direct dealths
Canadian govt. decleared state of emergency
3,000+ firefighters, helicopters an water bombs deployed
Canadian red cross raised $50 million in donations
Alberta govt. gave evacuees $1,250 per adult and $500 per child to help with living expenses
129
Long term responses to the Alberta wildfires
** stronger building regulation**
- must be fire-resistant
Public education campaigns
130
What is ridge push - simple
magma rises as the plates move apart. The magma cools to form new plate material. As it cools It becomes denser and slides down away from the ridge. This causes other plates to move away from each other.
131
What did robert kates in 1971 say about hazard perception on the east coast of usa
1971 Robert kates - found the most people who had experiences of storm damage previosuly pn the east coast of the US didnt expect such damage to happen agaiin
