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Hazards Flashcards

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1
Q

forms and nature of natural hazards

geophysical

A

caused by land processes

including earthquakes, landslides, volcanic eruptions and tsunamis

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2
Q

forms and nature of natural hazards

atmospheric

A

caused by climatic processes

include tropical cyclones, storms, draughts, extremes of hot/cold weather and wildfires

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3
Q

forms and nature of natural hazards

hydrological

A

caused by water movement

include floods and avalanches

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4
Q

hazard perception

A

some believe they will never experience a particular hazard, others adapt their lifestyle to minimise risk and others accept that hazards are beyond their control

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5
Q

economic/social/cultural factors determining hazard perception

A

wealth: rich can afford to move away from hazard/built homes resistant
religion: hazards as acts of god to punish
education: better education = better understanding of risks/able to reduce or mitigate impacts
past experience
personality: fear/excitement

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6
Q

human responses

fatalism

A

hazards cannot be avoided so they must just be accepted

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7
Q

human responses

prediction

A

working out when and where a hazard might occur which allows people to respond to it by evacuating therefore reducing impacts

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8
Q

human responses

adaption

A

reducing impacts through adaption e.g. adding earthquake resistant features to buildings

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9
Q

human responses

mitigation

A

reducing the impacts of a hazard, e.g. through adaption or prediction

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10
Q

human responses

management

A

governments may coordinate responses to a hazard to manage it correctly

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11
Q

human responses

risk sharing

A

sharing the costs of reducing a hazard, benefits or it or the costs of not preventing it, e.g. insurance

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12
Q

responses in relation to hazard incidence

magnitude/intensity

A

how powerful the hazard is

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13
Q

responses in relation to hazard incidence

level of development

A

less developed countries may lack the wealth and technology to manage hazards effectively

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14
Q

the park model of human responses to natural disasters

stages

A

pre disaster: normal, before event

disruption: during/directly after disaster, destruction of property/loss of life
relief: saving people/preventing further damage
rehabilitation: resolve longer term probs, temporary shelter/aid
reconstruction: re building houses/infrastructure, same standard/higher

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15
Q

the hazard management cycle

A

mitigation: before or after, minimising impacts e.g. flood defences or fire resistant roofs
preparedness: planning how to respond, e.g. warning systems
response: how people react when a disaster occurs e.g. emergency services rescuing
recovery: getting the effected area back to normal, e.g. repairing/rebuilding houses.

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16
Q

the park model of human responses to natural disasters

A

shows how responses progress during a disaster which may help planners predict what resources will be needed at each stage
also help planners to prepare for future hazard events, mitigating impacts

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17
Q

natural hazards potential impacts

A

emergency responses, e.g. evacuating area

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18
Q

disaster definition

A

when a hazard actually seriously affects humans

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19
Q

hazard defintion

A

something that is a potential threat to human life or property
natural hazards are caused by natural processes

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20
Q

risk definition

A

the likelihood that humans will be seriously affected by a hazard

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21
Q

vulnerability definition

A

how susceptible a population is to damage caused by a hazard

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22
Q

responses in relation to hazard incidence

distribution

A

the areal extent of a hazard

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23
Q

responses in relation to hazard incidence

incidence

A

how often a hazard occurs

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24
Q

the park model of human responses to natural disasters

A

shows how responses progress during a disaster which may help planners predict what resources will be needed at each stage
also help planners to prepare for future hazard events, mitigating impacts

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25
Q

what is the earth’s structure

A

inner core, outer core, mantle, asthenosphere, lithosphere, crust

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26
Q

about the core

A

inner: solid ball containing iron and nickel
outer: semi molten containing iron and nickel

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27
Q

about the mantle

A

most made of silicate rocks
nearest core: quite rigid
layer above that: asthenosphere, semi molten
top: rigid

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28
Q

about the crust

A

rigid top part of mantle + crust: lithosphere
continental crust: thicker and less dense
oceanic: thinner and more dense

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29
Q

the earth’s internal energy sources

A

the main source of internal energy is the core and the mantle as they are very hot
some of the heat is left over from when the world was formed and some comes from radioactive decay of elements such as uranium

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30
Q

plate tectonic theory:

tectonic plates

A

the lithosphere is divided into slabs called tectonic plates which move in relation to each other
the places where the plates meet are called plate boundaries/plate margins

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31
Q

plate tectonic theory:

ridge push/gravitational sliding

A

at constructive plate margins magma rises to the surface and forms new crust which is very hot, this heats the surrounding rocks which expand and rise above the surface of the surrounding crust forming a new slope
the new crust cools and becomes denser, gravity causes the new crust to move downslope, away from the plate margin
this puts pressure on the tectonic plates causing them to move apart

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32
Q

plate tectonic theory:

slab pull

A

at destructive plate margins denser crust is forced under less dense crust
the sinking of the plate edge pulls the rest of the plate towards the boundary

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33
Q

plate tectonic theory:

convection currents

A

the earth’s mantle is hottest closest to the core so lower parts of the asthenosphere heat up, become less dense and slowly rise
as they move towards the top they cool down, become more dense and slowly sink
these circular movements of semi molten rock are known as convection currents
they create drag on the case of the tectonic plates, causing them to move

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34
Q

plate tectonic theory:

sea floor spreading

A

as tectonic plates diverge magma rises up to fill the gap created, then cools to form new crust
over time the new crust is dragged apart and even more new crust forms between it
when this happens at a plate margin under the ses the sea floor gets wider: sea floor spreading
it creates mid ocean ridges: ridges of higher terrain on either side of the margin

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35
Q

what are destructive plate margins

A

when two margins are moving towards each other (converging)

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36
Q

what are constructive plate margins

A

two plates are moving apart (diverging)
the mantle is under pressure from the plates above, when they move apart pressure is released at the margin
the release of pressure causes the mantle to melt producing magma

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37
Q

what are conservative plate margins

A

where two plates are moving past each other, the two plates get locked together in places and pressure builds up

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38
Q

conservative plate margins
characteristic processes
seismicity and vulcanicity

A

pressure build up causes plates to jerk past each other or to crack forming fault lines
releasing energy as an earthquake
e.g. pacific and north american plates: san andreas fault line in california

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39
Q

magma plumes

A

a magma plume is a vertical column of extra hot magma that rises up from the mantle
volcanos form above magma plumes
as the tectonic plate moves the volcanic activity subsides but the magma plume remains in the same place causing a chain of volcanic islands, e.g. hawaii

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40
Q

magma plumes

A

a magma plume is a vertical column of extra hot magma that rises up from the mantle
volcanos form above magma plumes
the magma plume remains stationary over time but the crust moves above it
the volcanic activity in the part of the crust the was above the magma plume decreases as it moves away
new volcanos form in the part of the crust that is now above the magma plume
as the crust continues to move a chain of volcanos is formed
e.g. hawaii

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41
Q

destructive plate margins

oceanic-continental

A

where continental crust and oceanic crust converge, the more dense oceanic crust is subducted under the less dense continental crust
this forms a deep sea trench
fold mountains also form where the plates meet, made up of sediments that have accumulated on the continental crust which are folded upwards along with the edge of the continental crust
the oceanic crust is heated by friction and contact with the upper mantle which melts it into magma
the magma is less dense than the continental crust and will rise back to the surface to form volcanos
as one plate moves under the other they can get stuck which causes pressure to build up, when the pressure becomes too much the plates jerk past each other causing an earthquake

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42
Q

destructive plate margins

oceanic-oceanic

A

most of the same processes as oceanic-continental,
denser of the two will be subducted forming a deep sea trench and triggering earthquakes and volcanos
volcanic eruptions that take place underwater (when oceanic-oceanic converge) they create island arcs, clusters of islands that sit in a curved line, e.g. mariana islands

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43
Q

destructive plate margins

continental-continental

A

neither is subducted so no

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44
Q

destructive plate margins

continental-continental

A

neither is subducted so no volcanos but pressure build up between them can cause earthquakes
fold mountains form e.g. himalayas

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45
Q

volcanic hazards

at constructive margins

A

basaltic lava: very hot and low viscosity so flows easily and quickly, eruptions are frequent and go on for a long time but they’re not violent
if the margin is underwater magma rises to fill the space left by plates moving apart forming ocean ridges
if the margin is on land as plates pull apart forming rift valleys they become thinner and magma is able to break through the surface

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46
Q

volcanic hazards

at destructive margins

A

adesitic and rhyolitic lavas are formed here, they are cooler and more viscous than basaltic lava so they flow less easily. andesitic and rhyolitic lavas usually erupt intermittently and the eruptions are short lived
at subduction zones where one plate is pulled underneath another, melting of the plate forms magma, which rises to the surface as volcanos. because the lava is viscous, it forms blockages in volcanic events causing pressure to build. the blockage is cleared by a violent eruption

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47
Q

volcanic hazards

at hot spots

A

few volcanos form away from plate margins at hot spots above magma plumes
most hot spots have basaltic lava that flows quickly, forming volcanos with gentle slopes (shield volcanos)

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48
Q

volcanic hazards
primary hazards
pyroclastic flows/nuee artendes

A

a mixture of super heated gas, ash and volcanic rock that flows down the side of a volcano, travels and high speed and a flows long way
because they travel fast and happen with relatively little warning, pyroclastic flows can cause widespread death and destruction through e.g. burning and burial

49
Q

volcanic hazards
primary hazards
lava flows

A

can flow from a volcanic vent down the side of a volcano
the speed of the flow and distance travelled depends on the temp and viscosity of the lava as well as the steepness of the slope
most flows are relatively slow so people have time to evacuate areas that will be affected, however laval flows destroy anything in their path including buildings and vegetation, by burning, burying or knocking down

50
Q

volcanic hazards
primary hazards
volcanic gases

A

lava contains gases such as carbon dioxide and sulfur dioxide which are released into the atmosphere when a volcano erupts
some of these gases can be harmful to humans and animals if they’re breathed in e.g. sulfur dioxide can cause breathing difficulties

51
Q

volcanic hazards
primary hazards
pyroclastic and ash fallout

A

pyroclastic fallout is material that has been ejected from a volcano during an eruption and falls back to the ground
when fallout consists of mostly ash, it is called ash fallout
range of sizes, from large pieces of rock to ash particles, can travel thousands of kms, heavier particles are deposited earlier than light ones so material ends up well sorted
larger pieces of falling tephra can damage buildings and kill or injure people. finer material can form a layer several metres thick which can kill vegetation, hinder road and rail transport and cause buildings to collapse. ash can be harmful if it is breathed in

52
Q

volcanic hazards
secondary hazards
mudflows/lahars

A

occur when volcanic material mixes with large amounts of water from rainfall or ice melt, flows move quickly and can travel 10’s of kms
mudflows can bury or destroy natural habitats, settlements and infrastructure

53
Q

volcanic hazards
secondary hazards
acid rain

A

volcanic gases can react with water vapour in the atmosphere which then falls as acid rain, e.g. sulfur dioxide reacts with water to form weak sulfuric acid
this can damage ecosystems and can also cause stone and metal to deteriorate damaging buildings, bridges and statues etc

54
Q

volcanic hazards

magnitude

A

small slow lava flows to huge eruptions of lava, ash and gas
magnitude can be measured using the volcanic explosivity index which grades volcanos 0-8 based on the amount of material ejected and how high material is blasted

55
Q

volcanic hazards

frequency

A

how often they erupt, less frequent are larger in magnitude and more damaging

56
Q

volcanic hazards

randomness vs regularity

A

some erupt at regular intervals whereas some remain dormant for years then erupt several times in quick succession

57
Q

volcanic hazards

predictability

A

the regularity with which a volcano erupts can help scientists to predict when it might erupt again.
they also monitor tiny earthquakes and changes in the shape of the volcano which suggests that an eruption is imminent

58
Q

volcanic hazards

primary impacts

A

a direct result of the eruption, e.g. people being killed by falling tephra

59
Q

volcanic hazards

secondary impacts

A

occur as a result of the primary impacts e.g. pyroclastic flows can melt glaciers and cause flooding

60
Q

volcanic hazards
impacts
social

A

people are killed
buildings and infrastructure destroyed by pyroclastic flows and fallout
pyroclastic flows and lava flows can start fires that damage buildings
mudflows and flooding from ice melt can cause further damage and deaths

61
Q

volcanic hazards
impacts
environmental

A

ecosystems damaged/destroyed by flows and fallout of volcanic material
acid rain can cause acidification of aquatic ecosystems, killing some plants and animals. also damages leaves of trees and removes nutrients from the soil, damaging forests
volcanic gases contribute to the enhanced greenhouse effect and can add to global warming
clouds of ash and volcanic debris can reduce the amount of sunlight reaching earth, decreasing temperatures over large areas

62
Q

volcanic hazards
impacts
economic

A

eruptions can destroy businesses and ash clouds can prevent aircraft flying and damage crops which damages the economy
damage to buildings and infrastructure is expensive to repair
eruptions and the scenery they form can attract tourists, boosting the economy

63
Q

volcanic hazards
impacts
political

A

damage to agricultural land can cause food shortages, leading to conflict and political unrest
governments may have to spend money on repairing damage to buildings and roads rather than hospitals and schools so countries may not develop as rapidly

64
Q

volcanic hazards
responses
short term

A

normally occur immediately before, during or immediately after the hazard begins, includes evacuating people from areas at risk and providing emergency food supplies.

65
Q

volcanic hazards
responses
long term

A

designed to reduce the impacts of future eruptions by managing risks

66
Q

volcanic hazards
responses
long term
prevention

A

not possible to prevent a volcanic eruption

possible to prevent eruptions posing a risk to people, e.g. authorities prevent land around a volcano being developed

67
Q

volcanic hazards
responses
long term
preparedness

A

when happens before an eruption to minimise risk or vulnerability, e.g.
monitoring systems to predict when an eruption may occur and make plans for how they will evacuate people
if an eruption is imminent authorities can stop people entering the area
individuals can find emergency shelter/make emergency kits
search and rescue teams or fire response units

68
Q

volcanic hazards
responses
long term
adaption

A

changing behaviour or surroundings to minimise risks amd maximise benefits of living near a volcano
buildings can be strengthened to reduce the chance of collapse if a layer of ash lands on them
people can capitalise on opportunities of living near a volcano e.g. by farming or working in the tourist industry

69
Q

seismic hazards

earthquakes

A

the primary hazard associated with a seismic event
caused by tension that builds up at all 3 types of plate margin
when the plates jerk past each other it sends out shockwaves; these shockwaves are the earthquake
shockwaves spread out from the focus, could be the fault line. near the focus the waves are stronger and cause more damage
the epicentre is the point on the earth’s surface where the earthquake is felt first, it is directly above the focus
earthquakes cause the ground to shake and sometimes rupture along the fault

70
Q

seismic hazards

tsunamis

A

large waves caused by the displacement of large volumes of water
can be triggered by underwater earthquakes, they cause the seabed to move which displaces water. waves radiate out from the epicentre of the earthquake. the greater the movement of the sea floor, the greater the volume of water displaced and the bigger the wave produced
usually more powerful if it starts closer to the coast because waves lose energy as they move towards land
waves travel very fast in deep water so they can hit the shore without much warning meaning they can cause a high death toll

71
Q

seismic hazards

landslides and avalanches

A

shaking of the ground can dislodge rock, soil, or snow causing landslides or avalanches that move downslope quickly
shaking can also loosen ground material, making it easier for water to infiltrate. the weight of extra water may trigger a landslide even after ground shaking has stopped

72
Q

seismic hazards

soil liquefaction

A

when soil is saturated with water, the vibrations of an earthquake can cause it to act like a liquid
this makes the soil weaker and easier to deform so it is more likely to subside, especially where it has a heavy weight on top of it, e.g. a building

73
Q

the nature and magnitude of an earthquake

margin type

A

biggest earthquakes occur at destructive plate margins
the subduction of a plate causes massive pressure to build up causing a huge earthquake when its released
earthquakes at constructive margins tend to be lower magnitude than destructive or conservative

74
Q

the nature and magnitude of an earthquake

rate of movement

A

tectonic plates move in relation to each other at different rates, 1-15cm per year
no clear relationship between rate of movement and earthquake magnitude

75
Q

the nature and magnitude of an earthquake

depth of focus

A

the focus can be close to earth’s surface or deep below it
deep focus earthquakes tend to be higher magnitude than shallow focus earthquakes. however, deep focus earthquakes generally do less damage than shallow focus earthquakes because shock waves generated deeper in the the earth have to travel further to reach the surface which reduces their power

76
Q

seismic hazards

magnitude and frequency

A

100’s of low magnitude earthquakes happen every day, earthquakes of high magnitude occur much less often, the number of earthquakes globally varies year to year

77
Q

seismic hazards

randomness vs regularity

A

occurrence is largely random

78
Q

seismic hazards

predictability

A

scientists can monitor the movement of tectonic plates to predict which areas are at risk from seismic hazards however it is currently impossible to tell when an earthquake will strike a particular place and what magnitude it is likely to be

79
Q

seismic hazards
impacts
social

A

buildings collapse, killing and injuring people and leaving others homeless
earthquakes and liquefaction cause gas and power lines to break, starting fires that kill more people.
broken pipes cause flooding and lack of water makes it hard to put out fires
lack of clean water can cause disease to spread
tsunamis can flood large areas killing people and causing widespread damage to property

80
Q

seismic hazards
impacts
environmental

A

industrial units including powerplants can be damaged by earthquakes and tsunamis causing leaks of chemicals or radioactive material that damages the environment
fires started by damaged gas and electricity lines can destroy ecosystems
tsunamis can flood freshwater ecosystems, killing plants and animals and salinising water and soil

81
Q

seismic hazards
impacts
economic

A

earthquakes can destroy business premises through ground shaking and liquefaction, this damages the economy
damage to industry may mean that the country has to rely on expensive imports of goods and energy
damage to buildings and infrastructure can be very expensive to repair

82
Q

seismic hazards
impacts
political

A

shortages of food water and energy can cause conflict and political unrest
governments may have to borrow money to repair damage, putting the country in debt
money that is earmarked for development may have to be spent on repairing damage rather than development

83
Q

seismic hazards
responses
prevention

A

not possible to prevent most seismic hazards
sometimes possible to prevent them posing a risk, e.g. authorities can prevent land that is prone to liquefaction from being build on or build giant sea walls to prevent tsunamis hitting land

84
Q

seismic hazards
responses
preparedness

A

earthquake warning system
individuals and businesses have plans of how to respond, e.g. staying away from buildings if possible, finding a strong door frame or desk to shelter under
tsunami warning systems and evacuation routes well signposted
search and rescue teams or fire response units

85
Q

seismic hazards
responses
adaption

A

adapt behaviour or surroundings to minimise risks
buildings designed to withstand earthquakes, e.g. strong or flexible materials
buildings designed to reduce vulnerability to tsunamis e.g. tall strong buildings allow people to escape the tsunami quickly, and buildings with raised, open foundations are less likely to be damaged

86
Q

how are earthquakes measured

A

1) the richter scale: measures how powerful the shaking is, doesnt have an upper limit and is logarithmic (mag of 5 is ten times greater than mag of 4) major earthquakes 7+
2) the moment magnitude scale: based on total amount of energy released, logarithmic and has no upper limit, more accurate than richter scale
3) the mercalli scale: measures the impact of the earthquake using observations of the event, e.g. reports and photos, scale is 1-12

87
Q

what is a tropical storm

A

huge spinning storms with strong winds and torrential rain
they develop over warm water, as warm moist air rises and condenses, it releases energy that increases wind speed
they are circular in shape, hundreds of kms wide and last 7-14 days
they spin anticlockwise in the northern hemisphere and clockwise in the southern hemisphere
at the centre of the storm there is an area of low pressure called the eye
rising air spirals around the eye in the eyewall, causing strong winds
near the top of the storm there is an outflow of moisture laden air so cloud cover extends for a long distance either side of the eye

88
Q

how are tropical storms formed

A

form in the tropics because the water is warm enough
occur in the caribbean sea: hurricanes
the bay of bengal: cyclones
the china sea: typhoons
and in northern autralia
tropical storms lose strength when they move over land because their supply of warm moist air is cut off
they initially move westwards due to easterly winds in the tropics e.g trade winds move cyclones west across the atlantic ocean
they move away from the equator because of the coriolis effect

89
Q

how is storm magnitude measured

A

using the saffir simpson scale which is based on wind speed. category 5 is the strongest and 1 is the weakest
also estimates how much damage a storm of a given magnitude will do, from limited to catastrophic

90
Q

storm hazards

frequency

A

tropical storms are quite frequent, around 100 per year
some never reach land so never develop into a major hazard
storms are more frequent in the northern hemisphere between june and november
and more frequent in the southern hemisphere between november and april

91
Q

storm hazards

regularity

A

lots of factors that affect when and where a tropical storm will form and where it will land so the hazards created by storms are largely irregular
follow no clear spatial or temporal pattern

92
Q

storm hazards

predictability

A

certain cloud formations in tropical areas can be identified from satellite imagery and used to tell when a tropical storm is forming. the storm can then be tracked using satellite imagery and models, helping scientists work out when and where it might hit land. the path of a tropical storm can therefore be predicted fairly accurately

93
Q

what are storm hazards

A

high winds: 300km/h+, destroy buildings, uproot trees, carry debris long distances and smash them into other objects
storm surges: a large rise in sea level caused by high winds pushing water towards the coast and by the low pressure of a storm
heavy rain: warm moist air cools and condenses it causes torrential rain
flooding: heavy downpours cause river discharge to increase suddenly causing rivers to overtop their banks and flood the surrounding area. heavy rain and storm surges can also cause flooding in coastal areas
landslides: water infiltrates soil and rock making it less stable and increasing the risk of landslides

94
Q

storm hazards
impacts
social

A

people may drown/be injured or killed by debris
houses are destroyed so people are left homeless
electricity cables are damaged and supplies are cut off
flooding causes sewage overflows, contaminating water
the lack of clean water can help diseases spread
damage to agricultural land can cause food shortages

95
Q

storm hazards
impacts
political

A

people may blame authorities for shortages of food/water/energy, leading to conflict and political unrest
expensive repairs limit the amount of money that can be spent on development

96
Q

storm hazards
impacts
economic

A

buildings and infrastructure are expensive to rebuild
business are damaged/destroyed so cant trade
agricultural land is damaged, affecting commercial farming

97
Q

storm hazards
impacts
environmental

A

beaches are eroded and coastal habitats e.g. coral reefs are damaged. sediment deposited in aquatic ecosystems may damage fish breeding grounds
environments are polluted e.g. by salt water, oil and chemicals spilled from damaged factories
landslides can block watercourses so they change course

98
Q

storm hazards
long term responses
prevention

A

storms cannot be prevented but they can be studied to help scientists understand which areas are most likely to be affected which means that future developments can be planned to avoid high risk areas

99
Q

storm hazards
long term responses
preparedness

A

emergency services train and prepare for disasters, governments plan evacuation routes to get people away from storms quickly and educate people about how to prepare about how to prepare for a storm e.g. stock piling water and food and boarding up windows

100
Q

storm hazards
long term responses
adaption

A

buildings can be designed to withstand tropical storms e.g. by using reinforced concrete or by fixing roofs securely so they’re not blown off
buildings can also be put on stilts so they’re safe from floodwater
flood defences can be built along rivers and coasts

101
Q

what are wildfires

A

uncontrolled fires that destroy forests, grassland, and other areas of vegetation. usually occur in rural areas but if they reach inhabited areas they will also destroy agricultural land and settlements

102
Q

types of wildfire

ground fire

A

where the ground itself burns

it is a slow, smouldering fire with no flame and little smoke

103
Q

types of wildfire

surface fire

A

where leaf litter and low lying vegetation burn, fire can be low or high intensity

104
Q

types of wildfire

crown fire

A

where fire moves rapidly through the canopy (top layer of vegetation)
fires are more likely to be intense and fast moving

105
Q

conditions for an intense wildfire

vegetation type

A

thick undergrowth or closely spaced trees allow fire to travel easily
eucalyptus and pine contain a lot of oil so burn easily
eucalyptus trees shed strips of their bark which helps the fire to spread quickly

106
Q

conditions for an intense wildfire

fuel characteristics

A

fine, dry material catch fire and burn most easily

large amounts of fuel that form a continuous cover will help the fire burn for longer and spread

107
Q

conditions for an intense wildfire

climate and recent weather

A

rainfall must be sufficient for vegetation to grow so there’s plenty of fuel
the area usually has a distinct dry season when rainfall is low for a significant time. warm, dry weather causes water in the vegetation to dry up so its more flammable
strong winds provide more oxygen to help the fire burn and spread burning embers

108
Q

conditions for an intense wildfire

fire behaviour

A

creeping fire moves across the ground surface fairly slowly whereas a running fire spreads rapidly and is more intense
fires can throw out burning debris (firebrands) that help the fire spread and become more intense

109
Q

wildfires
causes
natural

A

fuel, oxygen, heat

heat: lightening especially without rain, volcanic eruptions produce hot lava, gas or ash which starts fires

110
Q

wildfires
causes
human

A

fuel, oxygen, heat
most fires are started by people
this can be accidental, e.g. by dropping cigarettes, allowing campfires or barbecues to get out of control, pr if fireworks/sparks from machinery land in vulnerable areas
can also be started on purpose: arson

111
Q

wildfires
impacts
social

A

people killed or injured if they don’t evacuate in time
homes destroyed so people left homeless
destroy powerlines and damage reservoirs, leaving people without electricity or clean water
health problems e.g. smoke inhalation

112
Q

wildfires
impacts
political

A

governments can face criticism when wildfires have severe impacts
governments may have to change their forest management practices to reduce the risk of wildfire e.g. clearing vegetation to limit fuel

113
Q

wildfires
impacts
economic

A

wildfires destroy businesses, leading to loss of jobs and income
insurance premiums increase drastically after a wildfire
cost of fighting wildfires is huge
wildfires may discourage tourists from visiting an area, reducing income

114
Q

wildfires
impacts
environmental

A

habitats are destroyed. some species may not return to an area after a wildfire, changing the ecosystem
soils are damaged as fire removes organic matter
smoke causes air pollution and water sources can be contaminated with ash
some ecosystems rely on wildfires to clear dead vegetation and some plant seeds need mire to germinate

115
Q

wildfires
responses
short term

A

trying to put out the fire, diverting it away from settlements, evacuating people from areas at risk and spraying water on to roofs of houses to prevent embers from setting them alight

116
Q

wildfires
responses
prevention

A

public education about the risks of using campfires and barbecues in vulnerable areas
authorities may provide fire beaters to put small fires out before they spread

117
Q

wildfires
responses
preparedness

A

households having an emergency plan and emergency supplies of food, water and medicine or authorities making emergency shelters available

118
Q

wildfires
responses
adaption

A

non flammable building materials and creating fire breaks (gaps in trees) around settlements to stop fire spreading

Geography (11 decks)

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