Hazards Flashcards
Lithosphere
The solid top layer of crust in which plates are formed, consists of crust and upper mantle
Asthenosphere
Soft plastic like rock in the upper mantle just below the lithosphere
Core temp of earth
5000-7000 degrees c
Evidence of tectonic theory
Jigsaw fit Glacial deposits fossil evidence geological fit tectonic fit
thickness of continental crust
35 - 40 km
thickness of oceanic crust
7 - 10 km
slab pull
when the oceanic crust is pulled into the mantle - at subduction zones (so destructive plate margins)
ridge push
(constructive margins) where magma forces upwards, pushing plates apart
age of continental crust
2 billion
age of oceanic crust
no more than 200 million
types of destructive boundry
collision
oceanic/oceanic
oceanic/continental
density of continental crust
2.7g/cm3
example of a fault line
san andreas
density of oceanic crust
2.9g/cm3
potential cost of an earthquake along the san andreas fault
$33 billion
mineral content of continental
Si Al and oxygen
mineral content of oceanic
Si Mg and oxygen
what plate boundary do fault lines form
conservative
what plates are involved in the san andreas fault
pacific and north american
why are conservative boundaries the most deadly
little warning given and very powerful
landforms associated with constructive boundaries
mid ocean ridge
rift valleys
example of a rift valley
east african rift valley
landforms of an oceanic/continental destructive boundary
oceanic trench
composite volcanoes
earthquakes
fold mountains
features of oceanic/oceanic destructive boundary
earthquakes n tsunamis
ocean trenches
island arcs
which plate subducts in an oceanic/oceanic destructive boundary
the faster moving or marginally denser
example of collision fold mountains
himalayas
features of collision boundaries
powerful earthquakes
fold mountains
example of island arc
caribbean islands
example of oceanic/continental destructive boundary fold mountains
the andes in south america
types of volcano
composite
shield
Why is a continental/continental boundary a collision?
Bc they cannot subduct
Features of a composite volcano
Narrow base Steep sides High Viscous lava Ash
Volcanic hazard types
Lava flows Gases Lahars Ash fallout Pyroclastic flows Acid rain
Features of a shield volcano
Wide base
Non viscous lava
Steam
Gentle slopes
Hazard
a natural event which does (or have the potential to) cause people harm
Lava flows
A mass of flowing or solidified lava
least hazardous
Gases emitted in a volcanic eruption
sulphur dioxide and carbon monoxide are the main ones
Lahars
kinda like mudflows, a mix of water and ash that flows like a river and sets like concrete
Ash fallout
Rain of airborne ash from an eruption
Pyroclastic flows
Flows at high speeds consisting of ash and lava
Most deadly
Acid rain
Gases released from eruption mix with atmospheric water
hazard risk
the probability that a natural hazard may take place
Monitoring volcanoes
Gas emissions
Seismic activity
Geological observations
Gas emission monitoring volcanoes
Sulphur dioxide emitted before eruption it’s easily detectable
Seismic monitoring volcanoes
Seismographs put activity on Richter scale
Geological monitoring volcanoes
Tilt meter measures changes in slope
EDM measures horizontal movement
geophisical hazard
driven by the earth’s own internal energy forces
atmospheric hazard
driven by processes at work in the atmosphere
hydrological hazard
driven by water bodies, mainly the oceans
hazard perception
the way we see and react to hazards, it’s determined by economic and cultural factors
fatalist response
the losses are accepted as inevitable as there is little we can do to control the hazard - may be due to lack of alternatives (economic)
prediction response
as technology increases, the methods of predicting hazards are better
adaptation and adjustment response
natural events are inevitable so by adjusting our lives, the losses can be reduced
This is a realistic n cost effective response for governments
frequency
how often the hazard occurs
magnitude
how strong the hazard is
relief phase
immediate
search and rescue
what does the park model show
the country can improve after an event
rehabilitation phase
weeks or months
infrastructure restores
temporary structures
to allow the reconstruction phase to begin as quickly as possible
reconstruction phase
restoring to the same or better quality of life as before the event
spell the volcanic case study
Eyjafjallajokull
plates involved in icelandic eruption
american plate moved west while eurasian plate moved east at a rate of 2.5cm/year
plate boundary of icelandic volcano
constructive
when was the icelandic eruption
april 2010
rating of icelandic eruption on the vei
4
how thick was the ice cap that melted due to the icelandic eruption
150m thick causing widespread flooding
how many tonnes of co2 was emitted per day into the atmosphere by the icelandic volcano
30 000 tonnes
how much money did airlines and associated businesses lose due to the icelandic eruption
£130 million per day
what percentage of kenya’s economy was discarded due to the icelandic eruption
20% (based on the export of cut flowers and green veg)
how much did shares in air travel and tourism agencies drop by due to the icelandic volcano
4%
how much money did london’s tourism lose due to the icelandic volcano
£120 million
how many farms were destroyed due to the icelandic volcano
20
how many people were evacuated due to the icelandic eruption
800
what was distributed to prevent people choking on ash in the icelandic eruption
face masks
name two short term responses to the icelandic volcano
immediate grounding of air traffic and cut off parts of roads and bridges to prevent further damage from lahars and lava flows
how much did the EU spend in researching the dangers of flying in ash following the icelandic eruption
€6 million
what did the french red cross do to help after the icelandic eruption
set up two emergency shelters to help 400 people
what did the netherlands red cross do after the icelandic eruption
gave 1500 beds for stranded people
why did we study the icelandic volcano
it is hemispheric in scale
what earthquake did i study
nepal
why did i study the nepal earthquake
the magnitude and poor country
what number on the richter scale was the nepal earthquake
7.9
where was the epicentre of the nepal earthquake
between the capital of kathmandu and the city of pokhara
what is the gdp of nepal
$2465/year
which plates were involved in the nepal earthquake
eurasian plate moving towards the indo-australian plate
how rich is nepal
157/185
what tropical storm did i study for a mic
hurricane sandy
where did hurricane sandy begin
western caribbean on 22nd october 2012
where did hurricane sandy move to after developing in western caribbean
travelled north hitting haiti and cuba before hitting the east coast of america
why did i study hurricane sandy
unusual location - too far north
name some factors that influence people’s perception of a hazard
Socio-Economic status Personality Religion / ethnic background Level of Education Past experience Occupation
3 main ways to perceive a hazard
Fear- feel vulnerable
Adaptation- prepare- prevent and protect
Fatalism- part of the area- God’s will
two internal energy sources
Primordial Heat
Radiogenic Heat
primordial heat
Heat left over from Earth’s formation
radiogenic heat
Heat produced by the decay of isotopes like Uranium 238
By far the greatest source, but slowly diminishing
Explain Alfred Wagner’s theory (1912)
Continental Drift- 300 million years ago Pangea existed
Formation of shield volcanoes
Plates move apart
Magma rises to surface, cools = new crust
Sea floor spreading
Layers built by eruptions
shield volcano boundary
constructive
shield volcano example
Eyjafjallajokull, Iceland
formation of composite volcano
Plates move towards eachother Oceanic, denser, subducts Beinoff Zone Less dense molten material rises Layers of ash and lava build
composite volcano boundary
destructive
composite volcano example
Mount Etna, Italy
volcanoes in rift valleys formation
Brittle crust fractures
Areas drop down between parallel faults
Thin crust- forms magma
Magma forces its’ way to the surface
volcanos in hotspots formation
Concentration of radioactive elements below crust
Plume of magma rises
Breaks through surface
vei
volcanic explosivity index Logarithmic scale (0-8) measuring magnitude of eruption by height of eruption column and volume of tephra erupted
disadvantages of the vei
Doesn’t consider climate impact
Ash, lava and lava bombs all treated alike
location of icelandic volcano
Southern Iceland, beneath an ice cap
icelandic volcano how high was the ash plume
11km
where was the dominant lava flow of the icelandic volcano
to the west
why wash the ash from the icelandic volcano distributed at a high velocity
due to the jetstreams above iceland
seismicity
Earth shaking, which can be human induced through fracking, mining and reservoir construction
p waves
Fast moving, first to reach the surface
Travel through solids and liquids (crust, mantle, core)
High frequency
Like a ‘push’ from one end
s waves
Second waves to reach the surface
Travel through liquids (mantle)
Sideways movement, shaking earth at 90° to direction of travel
Do more damage than P waves
love waves
Slowest moving
Do most damage because of sideways movement
rayleigh waves
Radiate from epicentre in complicated, low frequency rolling motions
landslide
movement of rock, debris, or earth down a slope
landslide formation
ground shaking due to earthquake detablishes cliffs and steep slopes causes landslides and rockfalls
also caused by heavy rainfall
what factors make landslides worse
Steep gradient
High relief rainfall (saturates ground = unstable)
Shallow soil
Unstable rock
liquefaction
jelly like state of silts and clays resulting from intense ground shaking
liquefaction formation
Sand or soil mixes with ground water
Becomes very soft, causing subsidence and building collapse
acts like quicksand
what factors make liquefaction worse?
High ground water
Reclaimed soil
Sandy soil (loosely packed grain = more pore spaces to fill with water)
how far away from the capital of nepal was the earthquake
80km northwest
how long did the nepal earthquake last for
2 mins
what did the nepal earthquake measure on the richter scale
7.8 - 7.9
when was the nepal earthquake
25th april 2015
which plate was subducting under the eurasian plate in the nepal earthquake
indian
what’s the annual movement of the eurasian plate and indian plate (nepal earthquake case study)
45mm north-northeast
what has the plate movement between the eurasian and indian created (nepal case study)
the himalayas
why did the buildings in nepal collapse reasily
due to lack of suitable foundations and poor construction
name an ancient monument that collapsed in nepal
dharahara tower
how many dies roughly in nepal
8 000
how many people were killed at a base camp after the nepal earthquake triggered an avalanche
18 climbers and sherpas
where were communication lines and roads destroyed in nepal making the area totally isolated
ghorka region
how many were made homeless from the nepal earthquake
2.8 million
how many were injured in nepal
14 500
how many years has nepal been put back
100 years
what were there outbreaks of in nepal
cholera
how many children were deprived on a normal childhood in nepal
1.1 million
tropical storm
a violent rotaing storm which occurs in the mid lataitudes
tropical storm formation
Strong upward air movement draws water vapour from ocean surface
Air rises and cools- condensing= clouds
Condensing air releases energy, powering storm to draw up more water
Thunderstorms combine to form a giant storm
Eye develops
Storm gathers strength and energy from warm ocean
why does a storm develop an eye
as air rapidly descends in the centre
where are the strongest storm winds found
in the eye wall
what happens when a storm reaches land
energy cut off
friction slows in down
why do storms need oceans
stroms derive their moisture and energy from em
why do storms need high temps
the sea surface temp needs to exceed 27 degrees c
why can storms be formed at lower latitudes in the summer
bc it’s hotter meaning sea surface temp increases
why does there need to be atmospheric instability for a storm to form
as this is where storms are more likely to form as warm air is forced to rise
Why’s the rotation of the earth important? (Coriolis Effect)
A certain amount of ‘spin’ is needed to initiate the rotation of a storm
Why does there need to be a uniform wind direction at all levels for a storm to form
As different wind directions at different altitudes prevents the storm from attaining height and intensity
4 Hazards associated with storms
High winds (250km/h)
Storm surge
Coastal / River flooding
Landslides
Effects of high winds
Tear off roofs
Break windows
Damage communication networks (power cuts and fires)
Debris picked up by high winds- block roads, injure people, transport disruption
What causes storm surge?
Intense low atmospheric pressure and powerful surface winds- creating high waves
Effects of storm surge
Floods in low lying areas Death Freshwater pollution Destroys homes and infrastructure Agricultural land inundated with water- useless
When did Sandy begin as a tropical depression?
22nd oct
what path did sandy take
Northwards- Haiti and Cuba
Moved along the East Coast of America before turning west to strike New York
factors that caused sandy
low wind shear and warmer than usual waters
When did Sandy develop an eye and become upgraded to hurricane status?
24th oct
why did sandy turn west at the end
high pressure in greenland and jetstream
why was there significantly more chance of a storm surge from sandy
due to full moon in the area at the time
where did sandy begin
south of kingston, jamaica
how many dies in the usa bc of sandy
11
how many died in new york bc of sandy
41 1 woman from faling debris
which city’s famous broadwalk was shattered from sandy
atlantic city
what happened at one of the construction sites in nyc bc of sandy
a crane collapsed
which transport system was flooded bc of sandy
subway
how many gallons of diesel leaked bc of sandy
336 000 gallons
commuters in usa bc of sandy
stranded
hurricane sandy how many people were without power in the east coast of the usa
8.1 million
what was the diameter of typhoon haiyan
425km
what were the two natural causes of typhoon haiyan
low wind shear
warm pacific ocean
how did human interference make the formation of typhoon haiyan worse
Towns and cities on coastlines- high populations
Global warming- sea levels have risen by 20cm a year since 1990, and increased sea surface temperature
when was typhoon haiyan declared a typhoon
5th november 2013
typhoon haiyan is the … most intense tropical cyclone on record
4th
how many people died from typhoon haiyan
10 000
how many people were affected from typhoon haiyan
14 million
how many people were made homeless from typhoon haiyan
1.9 million
the day after typhoon haiyan
the philippines was declared to be in a state of national calamity and asked for international help
environmental effects from typhoon haiyan
oil and sewage leak into local ecosystems
what percentage of tacloban city government workers came into work
2.8%
how many homes were destroyed by typhoon haiyan
550 000
how many tons of rice were lost from typhoon haiyan
131 611
how much of the philippines agricultural exports do coconuts account for
50%
what happened to the coconut farms in the typhoon haiyan
they were completely flattened
why were there high levels of pollution in the following weeks of typhoon haiyan
because of poor sanitation
how many tons of sugar does the sugar regulatory administration reckon were lost from typhoon haiyan
50 000 - 120 000
why were fishing communities badly affected by typhoon haiyan
the storm destroyed all boats and fishing equipment
whats the 2 year wildfire project called that’s been launched in europe
IGNIS (2016)
what’s IGNIS aiming to do
improve the fire and rescue response by bringing together knowledge and expertise
example of a group involved in IGNIS
Northumberland Fire and Rescue Service
wildfire
any rural fire that’s uncontrolled and spreasing
three aspects of the fire triangle
oxygen heat and fuel
natural causes of wildfire
lightning and lava
human causes of wildire
falling power lines campfires fireworks arson agricultural burning (controlled fires)
el Nino effect
climate change in the pacific ocean where warm water in the western pacific ocean moves eastwards along the equator to south america
why does the el nino effect cause more inense burning
as it’s drier and hotter
why does drought favour more intense wildfires
low levels of retained water in plants - so burns more quickly
ladder fuel
live or dead vegetation allowing a fire to climb from the forest floor to the tree canopy, meaning the fire is more influenced by winds
two countries techniques on educating (preparedness for wildfires)
america - smokey bear and australia - tv adverts
what are computer simulations used to do for wildfires
model the fire’s track
two ways of spotting wildfires
aircraft survey large areas
satellites provide low resolution images
what do australia have on weather forecasts
fire danger ratings
two ways to prevent a wildfire
manage vegetation
manage built environment
where did the alberta wildfire start
a remote forested area to the south west of fort mcmurray
when did the alberta wildfire start
1st may 2016
when did the alberta wildfire meet the community of fort mcmurray
3rd may 2016
three reasons why the ground was dry in alberta wildfire
lack of winter snowfall
early snowmelt
warmer than average temperatures
two reasons why the vegetation in alberta was dry
april temperatures were high
low humidity
cause of alberta wildfire
idk probs human
why did the alberta wildfire become out of control
due to a shift in the wind direction - resulting in the blaze turning northwards towards for mcmurray
what caused fires to ignite in front of the main alberta wildfire, even jumping a 1km river
spotting (when the wind carries burning embers)
how many people were killed in the alberta wildfire
0 none
what percentage of homes in fort mcmurray were destroyed
15%
how many people were forced to flee from the alberta wildfire
90 000
how many of the 25 000 oil workers were evacuated bc of the alberta wildfire
1/3
what were homes left without bc of the alberta wildfire
basic services - electricity and water
why did mains water have to be boiled (secondary effect of the alberta wildfire)
as untreated water was allowed into pipes so firefighters could put out the fires
where were thousands of workers left unemployed and unpaid bc of the alberta wildfires
at oil sands
transport links were affected in the alberta wildfire including…
the nearby airport
alberta wildfire: how many major oil companies suspended operations plus give an example
9
e.g. Suncor
how many barrels of oil were lost per day in alberta
1.2 million for 14 days
give one reason for canada’s poor economic outlook in 2016
lost oil royalties
alberta wildfire secondary effects: why did world oil prices rise briefly? and when did they stabilise?
as the fire could have hit the heart of the oil patch
stabilised after the fire missed the heart of the oil patch
how much will rebuilding add to albertas economy
$1.3 billion in real GDP
why does the philippines location make it vulnerable to so many natural disasters
it lies on the rim of the pacific belt making it prone to typhoons, earthquakes, and volcanic eruptions
hazards in the philippines
Drought Seismic Activity Epidemic Flood Insect Infestation Storms Volcanoes Wildfires
how much of the land in the philippines is exposed to hazards
60%
how much of the philippines population is exposed to hazards
74% of the population
which project involves establishing hazard maps in 27 provinces (the philippines)
READY funded by AusAID
how are philippines local authorities trying to improve building quality
by enforcing building codes
what does the national disaster coordinating council do in the philippines
Utilises Calamity Fund
Advises the President
Ensures all agencies follow the same plan
Recommends when an area should be declared a state of national calamity
Engages public through activities, workshops and consultations
how is the department of education trying to increase awareness in the philippines
by covering topics like disaster preparedness in the curriculum
what percentage of each local governments’ income has to be put aside for the calamity fund in the philippines
5%
where is caracas
venezuela
name the hazards caracas is prone to
Seismic
Landslides
Storms
Floods
why hasn’t the government implemented the building codes it was advised to in caracas
can’t afford to
couldn’t be done where the illegally constructed shanty towns are
what has the government in caracas been told to do when it comes to disaster response
Include government officials, the military, non-government organisations and the public
Future response could be more coordinated
More effective than current methods
what should the residents in squatter settlements in caracas be educated in
using safer building techniques
where should open spaces be introduced in caracas
between buildings as they provide important gathering and distribution areas during a disaster
stages of the hazard management cycle
response
recovery
prevention
preparation
how many hygiene kits did christian aid distribute to 50 000 people after the earthquake in nepal
10 000
islamic relief gave food for how many people after the earthquake in nepal
2500
how much money did the asian development bank pledge to nepal after the earthquake
$200 million for rehabilitation
saffir-simpson scale
used to measure tropical storms
1 to 5
4 and 5 are v bad
1 on saffir simpson scale
very dangerou winds will produce some damage
2 on saffir simpson scale
extremely dangerous winds will cause extensive damage
3 on saffir simpson scale
devestating dmage will occur
4 on saffir simpson scale
catastrophic damage will occur
5 on saffir simpson scale
the worst
response to hurricane sandy in cuba
response was unprepared as hadn’t seen a storm for 60 years
response to hurricane sandy in hati
red cross ineffective at delivering to cut off areas
Medicines Sans Frontiers opened a cholera treatment centre
how many us airports were shut immediately bc of hurricane sandy
3
size of storm surge in cuba bc of hurricane sandy
9m
bad thing about the response in america from hurricane sandy
red cross too focused on publicity
why was a grant of $822 million given to america
hazards mitigation grant following hurricane sandy
how many children were vaccinated from measles in the philippines after typhoon haiyan
108 000
the response in the philippines after typhoon haiyan
more focused on long term responses e.g. save the children educating children about good hygiene
how much was budgeted in alberta for wildfire prevention and management
$139 million
how many volunteers did the alberta volunteer firefighters have
450
the park model
considers how the standard of living and economic status of affected areas change after a hazard
adaptation to a hazard
reducing the impacts by doing things to address effects of a hazard (dealing with the impacts)
mitigation of a hazard
things done to reduce the change of an event happening (dealing with the cause)
convection currents
the currents in the mantle that moves the plates
earthquake
a sudden release of pressure built up from plate movement
rift valleys
the heating and updoming of the crust leads to fracturing and rifting, as the sides of the rift move apart, central sections drop down to form rift valleys
tephra
<2mm is ash
2-64mm is lapilli
>64mm is bombs
lapilli
sand and pebbles ejected from a volcanic eruption
plinian eruptions
the worst
highly explosive, large eruption columns (up to 45km), range of tephra and pyroclastic flows including lava flows
icelandic eruptions
the safest
low viscosity, highly effusive, may have water so phreatic
magma viscosity
how runny the lava is
basaltic lava
very runny
shield volcanoes
found in iceland and hawaii
rhyolitic lava
viscous lava
seismic waves
s waves, love waves, p waves, rayleigh waves
seismograph
measures motion of the ground cause by an earthquae puts it on the richter scale
richter scale
quantitative
seisometer
logarithmic (10x bigger each step)
MMI - mercalli scale
observations
qualitative
smokey bear
in america, an advertisement to education children abrout wildfires
