Hazards Flashcards
1
Q
What are the three nature of hazards
A
Geophysical, hydrological, atomspherical
1
Q
What is risk
A
chance or probability of being affected by a natural event
2
Q
what is vulnerability
A
potential for loss due to exposure to physical hazards
3
Q
what is resilience
A
ability to prevent short term hazards from turning into a long term issue
4
Q
what is a hazard
A
threat that has potential to cause injury or loss of life resulting in economic and environmental issues
5
Q
what is hydrological nature of hazards
A
caused by occurrence movement and distribution of water and surface e.g flooding hail and droughts
6
Q
what is geophysical
A
tectonic e.g earthquakes volcanic eruption’s tsunamis rockfall
7
Q
what is atmospherical
A
processes operating in our atmosphere resulting in extreme weather e.g blizzards tournados sand storms bush fires
8
Q
What are the three perception of hazards
A
Fatalism, Adaptation, Domination
9
Q
what is fatalism
A
fatalistic tendencies. People seeing hazards as natural and part of life and acts from god ( religious ) events are random and we have to respond to them and loss of life and injury is expected
10
Q
what is domination
A
perception of hazard that believes in science and that they are predicable and magnitude can be predicted. And we can control them through engendering and technology
11
Q
What is adaptation
A
mixture of both 2 belief that hazards will happen and are influenced by human activity. Magnitude + frequency can be estimated based on past events
Pic populations are fatalistic due to lack of education
12
Q
Factors affecting perceptions
A
socioeconomic status
education
employment
religion cultural ethinic background
family
past experiences
values and expectations
13
Q
what does parks model show
A
the impacts on quality of life and how quickly it recovers
14
Q
What is the hazard risk management cycle
A
pre disaster post disaster and response
15
Q
what’s in pre disaster of the hazard management cycle
A
risk assessment mitigation
16
Q
what’s in response of the hazard management cycle
A
warning evacuation saving people assessing damnage providing emergency services
17
Q
what’s in post disaster of the hazard management scheme
A
reconstruction mitigation economic recovery infulstruture rebuilt assistance
18
Q
what is:
frequency?
Magnitude?
Distribution?
A
Frequency= amount of times a hazard occurs in an area
Magnitude= strength of event
Distribution= where the hazard takes place, special coverage of hazard and its geographic location
19
Q
Features of continental crust
A
lower density (lighter)
30-50km deep (thicker)
Over 1500 million years old (older)
20
Q
features of oceanic crust
A
High density (heavier)
6-8km (thinner)
less than 200 million years old (younger)
21
Q
what happens at a constructive plate boundary
A
- plates are moving away
- new crust created
- basaltic rocks
- shield volcanos (icelcand)
22
Q
what happens at destructive plate boundaries
A
- plates move towards eachother
- oceanic crust destroyed
- island arcs
- earthquakes
23
Q
what happens at conservative plate boundaries?
A
plates move sideways along eachother and rub causing earthquakes
24
how are fold mountains formed?
continental vs continental
collide not dense enough to subduct
crust folds and pushes up
25
how are volcanos formed
destructive plate boundary
oceanic vs continental collide
oceanic more dense so subducts less dense continental plate driven down to athstenesphere plate melts due to heat and friction
maga rises up to surface and cools
26
how is a deep ocean trench formed
destructive plate boundary
oceanic vs continental
more dense oceanic plate subducts under continental plate
pulling front of less dense plate down creating a trench
27
how is a mid ocean ridge formed
constructive boundary
2 oceanic plates pull apart moving away from eachother
allowing magma to rise
magma reaches ocean turns into lava and cools
28
how is an island arc formed
destructive plate boundary
oceanic plate vs oceanic plate
one is lighter than the other so is sub-ducted under and melting it rising it
as the plates move this happens repeatedly forming island arcs beneath the water
29
how are rift valleys formed
conservative boundary
2 continental plates pull apart moving away stretching out the crust until it breaks
as it stretches wider the valley drops deeper leading to a new body of water at the bottom of it
30
how is a hotspot formed
when a tectonic plate moves over an unsually hot part of the earths mantle it causes magma to rise
it’s a stationary plume of hot magma that rises from deep within the earth’s mantle and creates volcanos on surface
31
evidence for tectonics
seafood spreading
geological evidence
biological evidence
alfred wergner
plateomagnatism
convection currents
ridge push
slab pull
32
what is sea floor spreading
if it spreads is implied the earths getting bigger
33
what is geological evidence
jigsaw fit of south america and west africa
glacial deposits in south america india and antarctica
structural faults in brazil and west africa
similar rock sequences in canada and scotland
34
alfred werner belief
earth used to be all the same super continent called pangea which broke 200 million years ago
35
what is plateomagnatism
polarity of ancient magnetic partials in rocks that found the same patterns and rhat crust is moving away from plate boundaries
36
what are convection currents
heat driven cycles that occur in the earths mantle and cause of movement of tectonic plates
37
what are the 3 states of volcanoes
active, dormant , extinct
38
features of a composite volcano
destructive boundaries
taller
viscus (thick)
narrow base due to slow moving lava
steep sides
acidic due to gas bubbles
explosive eruptions
made up of layers of ash and lava
andesetic lava
39
features of a shield volcano
constructive boundaries
gentle eruptions
less viscus (runny)
lava escapes through vents meaning lots reaches surface
can cover long distances
large base shallow sides
basaltic lava
40
features of andesetic lava
viscus
cooler (800 degrees)
high silica content
flows short distances large base and cools
looses gas’s quickly so more viscus
steep sided
les frequent eruptions
pyroclastic flows
41
features of basaltic lava
Hot (1200 degrees)
less viscus (runny)
low silica content
flows take longer to cool
gas content kept so more mobile
gentle but more frequent eruptions
42
features of a pilinan eruption
magma has high silica content
highly explosive
lots of tephra
high viscus magma with high gas content
shoots 46km in air
eruptions last for days
pyroclastic flows
43
features of a hawaiian eruption
basaltic lava + their features
not so explosive
few pyroclastic flows rather than flowing lava
fire fountains formed
44
features of strombolian eruption
not dangerous
small quantities of magma
high velocity
high gas levels
morbidly lava flows but normally excess ash can lead to eruptions
45
primary effects of volcano and what are they
tephra - rock fragments and partials ejected into air
pyroclastic flows - fast moving hot volcanic hazard made up of ash gas and rock at 800 degrees
lava flows - stream of molten rock that pours out of volcano
volcanic gasses - carbon monoxide hydrogen surface and co2 emitted
46
secondary effects of a volcano and what are they
lahars - volcanic mudflow that’s a mixture of water mud and rock that flow quickly down slopes of volcano that’s hot and dense
flooding - eruptions melt glaciers causing rising sea levels
tsunami - ling high sea wave caused by under water eruptions and earthquakes and displacement of sea floor
climate change - volcanic ash reflects sunlight cooling earth
47
what are longitudinal waves
vibrations are along same direction as direction of travel they are also primary
48
what are transverse waves
vibrations are at a right angle to direction of travel and are secondary
49
what’s the difference between primary and secondary waves
primary waves are seismic waves that travel straight through the earths solids and liquids they also are detected first they are longitudinal waves where vibrations are along the same direction of travel. Secondary waves are slower and are deflected second as they travel at half the speed of primary. Secondary waves are also transverse meaning that vibrations are at a right angle to direction. The shadow zone is caused by S waves as P waves travel though the center of core however S waves cannot and travel around the core causing a P wave shadow zone
50
advantages and disadvantages of the richter scale (measures magnitude of EQ)
advantages: easy to understand
disadvantages: can’t give clear calculations to earthquakes
not accurate over 8
51
Advantages and disadvantages of moment magnitude scale
(based on total momentum release of EQ)
advantages: can describe very small earthquakes
disadvantages: confusing between this and the richter scale
52
mericali scale advantages and disadvantages
(based on damage of the EQ)
advantages: easy to under stand and no calculations required
disadvantages: personal opinion
53
what is liquefaction
when a violently shaken soil with high water content loose their mechanical strength and start to behave like liquid
54
what is slab pull
a force that results from denser oceanic plates sinking beneath less dense continental plates along a destructive boundary and subduction zone
55
what is ridge push
a force that drives tectonic plates down at mid ocean ridges where newly formed oceanic plates are warmer and less dense than surrounding plate material
57
58
what is a wildfire
an uncontrolled rural fire
59
3 types of fires
crown fire
ground fire
surface fire
60
what is a crown fire
spreads across tree canopy and affects forest areas
61
what is a surface fire
burns across surface vegetation
62
what is a ground fire
burns beneath the ground in layers of organic heat
63
triangle of fire
fuel
ignition
climatic weather conditions
fuel
oxygen
heat
64
human causes of wildfires
-discarded cigs
- failing power lines
- agricultural fires
- bbq
- campfires
- deliberate
65
physical causes of wildfires
- lightening
- volcanic lava
- earthquakes
- meteorite
66
why is the slope of the land important
in the day they go up
at night they go down
67
3 stages of wildfire grown
stage 1: preheating - water expelled from plants by flames
stage 2: flaming combustion - wood burns fast and as hot gassed burn
stage 3: glowing combustion - wood burns more slowly and at a lower temp
68
factors affecting wildfires
fuel:
flammable material in area more = quicker moving fire less = slower moving fire
weather:
temp
wind
moisture dry ground temp caused fuels to ignite faster
wind blows fire
slope:
wind blows fire upslope in the day and downslope at night
fire spreads upslope because of the greater radiant and heat
69
what is el niño
- cyclical climatic condition that occurred in a random day every 6-8 years
- warming of the pacific ocean of west coast of south america
- leads to change in global patterns of temp + rainfall
- some places suffer from devastating floods while others are affected by prolonged periods of drought e.g australia
70
Planes and helicopters drop fire retardants pros and cons
Pros = good visual perspective and don’t have to veg too close. Cons = specialists dangerous expensive
71
smoke jumpers parachute into wildfire and place retardant gel
ads = get to inaccessible areas
cons = really dangerous and need highly skilled individuals
72
woodland fire engines use special equipment to spray water
ads = quick to area, acres of road places, cheap
dis = waste of water, limited water supply
73
control lines
ads = possible to predict direction of fire
dis = time consuming, requires lots of people
74
back burning
pros = removes fuel
dis = time consuming , risky
75
evacuation
ads = limits casualties, less stress on emergency services
dis = lots of planning required, doesn’t protect property
76
GIS ( geographical information systems )
ads = possible to prevent direct of fire
dis = time consuming, needs workers
77
volunteers to help remove fuel
ads = cheap , extra help , reduced stress on emergency services
dis = getting people to start up is hard and takes lots of time
78
what is the tropical storm?
A low pressure spinning storm with high wind and torrential rain
79
what are the conditions for tropical storm?
next one
80
temperature for tropical storm to form and ocean depth
26 to 27° ocean needs to be 50 m deep
81
Air pressure of a tropical storm to form
Tropical storms form over warm ocean waters when warm, moist air rises rapidly, creating low pressure and drawing in more air, which then cools and condenses, forming clouds and thunderstorms that power the storm
82
what does the rotation of the Earth need to be for a tropical storm to form?
5° on each side
83
what is the coridollis effect?
the pattern of deflection taken by objects not firmly connected to the ground as they travel long distances around Earth
84
How can countries adapt and prepare for a tropical storm hazard?
governments can plan evacuation routes to get people away from storms quickly
Emergency services, prepare for disaster through participating in regular intervals
Early warning systems can be used to reduce number of deaths for example Bangladesh loudspeaker to alert people of a storm
85
what is an MHE
Multi hazardous environment
86
how are tropical storms formed?
Sea surface temperature is 27°C
Water needs to be 70 m deep
Warm, moist rises and condenses releasing huge amounts of energy
The rising creates an area of low pressure which increases surface winds
Tropical storms move west because of the easterly winds
Earths rotation and the core effect cause storm to spin around the central eye where rapidly descending air forms the powerful eye wall with the storm is the strongest
When the storm passes over land, it loses heat and moisture eventually losing energy
87
what are the different types of earthquake prediction (siesmic)
- siesometers - redord siesmic waves to identify increasing activity
- foreshocks - smaller shocks could lead to bigger one
- siesmic gaps - areas that are on a boundary but haven't had an earthquake for a long peroid of time
88
what are the different types of earthquake prediction (physical change)
ground deformation - pressure buildup
groundwater levels
satelight imageary
fault lines - areas prone to earthquakes
historical records
89
limitations of earthquake prediction
uncertainty
lic cant afford technology to help them predict these hazards leaving them more prone to disaster
short term predictions are unreliable
90
what does the ritcher scale do and what are the advantages and disadvantages of it
measures the magnitude of the eq from 1-10
ads- easy to understand
dis- cant give clear calculations to large eqs over 8
91
what does the moment magnitude scale do and what are the advantages and disadvantages of it
measures total momentum release of the earthquake
ads - can describe very small eq
dis - confusion between this and the ritcher scale
92
what does the mericalii scale do and what are the advantages and disadvantages of it
shows the damage of an eq
ads - easy to understand and there is no calculations or science involved
dis - opinion based
93
