Challenges of Natural Hazards (Tectonic Hazards) Flashcards
Define hazard risk
probability that a natural hazard may take place
Define natural hazard
natural event with chance to threaten or damage
Define conservative plate margin
tectonic plate margin where tectonic plates slide past each other
Define constructive plate margin
tectonic plate margin where rising magma creates new materials between diverging plates
Define destructive plate margin
tectonic plate margin where two plates are converging
Define earthquake
sudden or violent movement within Earth’s crust followed by a series of shocks
Define rift valley
steep valley where land has dropped as plates have moved apart
Where are rift valley’s found?
where two continental plate margins meet
Define immediate responses
reaction of people as disaster happens and immediate aftermath
Define long term responses
later reactions that occur weeks, months and years after the event
Define monitoring
recording physical changes to help forecast natural hazard
Define plate margin
margin between two tectonic plates
Define planning
actions taken to enable communities to respond and recover from natural disasters
Define prediction
attempts to forecast when and where a hazard will strike
Define primary effects
initial impact of natural event on people and property
Define protection
actions taken before hazard strikes to reduce its impact
Define richter scale
measurement of earthquakes
Define secondary effects
after effect that occurs as indirect impacts of natural hazard
Define shield volcano
wide base and gentle slopes
erupt frequently but non explosive
Where are shield volcanoes found?
constructive plate margins
Define tectonic hazard
natural hazard caused by movement of tectonic plates
Define tectonic plates
rigid segment of Earth’s crust
Define economic impact
effect of event on wealth
Define environmental impact
effect of event on landscape and ecology
Define social impact
effect of event on lives of people or community
Define a natural hazard
natural event that threatens people or has potential to cause damage, destruction or death
Define an atmospheric hazard
created in atmosphere by movement of air and water
Define terrestrial/geological hazard
created by movement of Earth’s tectonic plates or surface rock and soils
Define weather based hazards
created by rivers, sea or oceans
Define biological hazards
biological substance that poses threat to the health of people
Give examples of atmospheric hazards
hurricanes
tsunami
forest fire
drought
Give examples of terrestrial hazards
earth quakes
landslides
Give examples of water base hazard
flooding
tsunami
Give examples of biological hazards
diseases
What factors effect the impacts of a natural hazard?
frequency
location
magnitude
development
3 Ps
How does frequency affect impacts of a natural hazard?
frequently vs. infrequently
How does location affect impacts of a natural hazard?
geology
relief of land
How does magnitude affect impacts of a natural hazard?
size and strength
area impacted
What are the three Ps?
preparation
prediction
prevention
What is the crust?
solid layer, further part from inner core
How thick is the crust?
between 10 km and 60 km
What is the mantle?
hard at top but magma nearer middle
What occurs in mantle?
convection current
How thick is the mantle?
2900km
What is the outer core?
liquid area of iron and nickel
How hot is the outer core?
5,500 degrees Celsius
What is the inner core?
solid layer in centre
Why is inner core solid?
immense pressure
How thick is the inner core?
6,378 km thick
How hot is the inner core?
5,500 degrees Celsius
What are convection currents?
hot core causes magma to rise and sink
What is the effect of convection currents?
builds pressure and carries plates with it
What is slab pull?
denser plate pulls back to mantle under influence of gravity
What is the effect of slab pull?
pulls rest of the plate along with it
What is ridge push?
magma rises to form new plate material
What is the effect of ridge push?
tectonic plates move away from each other
What is continental drift?
continents pushed apart because of tectonic plates moving
What are the two types of crust?
continental
oceanic
Which type of crust is newer?
oceanic
Which type of crust is older?
continental
How thick is oceanic crust?
less than 10km thick
Which type of crust is more dense?
oceanic
Which type of crust is less dense?
continental
How thick is continental crust?
between 25km and 70km
Which type of crust sinks?
oceanic
Which type of crust does not sink?
continental
How old is oceanic crust?
most is less than 200 million years old
How old is continental crust?
most over 150 million years old
Why do destructive plate margin plates move together?
convection currents
Give an example of a destructive plate margin
Nazca and South American
What does subduction of oceanic plate at destructive margin cause?
pressure
- earthquakes
Why do earthquakes occur at destructive plate margins?
pressure created by oceanic plate being subducted
- suddenly released
Which plates cause a destructive plate margin to occur?
oceanic and continental
OR
two continental
What does a destructive plate margin form from an oceanic and continental plate?
volcanoes
ocean trenches
What does a destructive plate margin form from two continental plates?
ridge mountains
Give examples of features created by destructive plate margins
Atacama trench
Andes mountains
What are constructive plate margins?
two plates moving away from each other
What type of plates create a constructive plate margin?
two constructive plate margins
What occurs at a constructive plate margin?
magma rises meaning mantle fills gap and new crust is created
Give an example of a constructive plate margin
North American and Eurasian plate moving part
Give an example of a feature formed by a constructive plate margin
mid Atlantic ridge
What is a conservative plate margin?
two plates moving parallel at different speeds
What is created at conservative plate margin?
nothing
Give an example of a feature created by a conservative plate margin
San Andreas Fault
Give an example of a conservative plate margin
Pacific plate and North American plate
Where do volcanoes occur?
destructive and constructive plate margins
Where do earthquakes occur?
all types of plate margins
What is melted rock called?
magma
Why does melted rock rise?
less dense
What type of eruption occurs at destructive plate boundary?
violent
dramatic
explosive
What is melted rock called when it erupts?
lava
Where is a destructive plate boundary found?
when a continental plates meets an oceanic plate
Why are plates moving apart at a constructive plate margin?
ridge push
convection currents
Are earthquakes high magnitude or low magnitude at a constructive plate margin?
low magnitude
What type of magma cools between Eurasian and North American plate?
basaltic magma
Why are volcanoes not found on conservative plate boundary?
land is not created or destroyed
Why do earthquakes occur at conservative plate boundaries?
friction and pressure build when plates stick
- vibration released
Where do volcanoes form, if not on a boundary?
hotspots like Hawaii
How do volcanoes form at destructive plate boundaries?
denser plate moves into mantle, where it melts
rises through cracks called vents
erupts forming volcano
How do volcanoes form at constructive plate boundaries?
magma rises into gap
forming volcano
What does a volcano emit when it erupts?
lava
gases
ash
What are pyroclastic flows?
super heated currents of gas ash and rock
How are earthquakes formed?
tension building up at plate marign
How do earthquakes form at destructive plate margin?
tension builds as one plate gets stuck to the other
How do earthquakes form at constructive plate margin?
tension builds along cracks in plates as they move away from each other
How do earthquakes form at conservative plate margin?
tension builds up when plates that are grinding past each other get stuck
What is the epicentre?
point on earths surface above focus
What is the focus?
the point where earthquake starts in the Earth
What is a collision plate margin?
when to continental plates move towards each other and collide
Why are the plates a collision margin moving together?
convection current and slab pull
Give an example of a feature formed by collision plate margin
Himalayas
Give an example of a collision plate margin
eurasian plate and indian plate
Why do fold mountains occur at collision plate margin?
neither plate can be destroyed
What occurs at collision plate margin?
earthquakes
What does not occur at collision plate margins?
volcanoes
Why do earthquakes occur at collision plate margins?
build up of friction and pressure
Why do volcanoes not occur at collision plate margins?
no land destroyed or made
Why do volcanoes occur on hotspots?
thin plate
Where do volcanoes form?
boundaries of tectonic plates
hotspots
What are the three types of volcano?
cinder cone
shield
composite
What forms when magma cools?
igneous
What type of volcano is the most dangerous?
composite
- forceful
- ash and lava
- pressure - earthquake
Define active volcano
can still erupt
Define dormant volcano
wont erupt in near future
Extinct volcano
wont erupt again
How do volcanoes originate?
molten rock originates in mantle - powered by Earth’s inner heat
How does magma enter magma chambers?
buoyancy and gas pressure molten rock - forces way upward
What causes the surface to bulge when forming a volcano?
material accumulates and exerts pressure on surface
What effect does bulge in surface have on the earth?
fissures and cracks form - material forces way upwards
What causes a volcano to erupt?
magma breaks through weaknesses in surface in fissures and cracks
What creates sticky lava?
high gas pressure
What creates runny lava?
low gas pressure
What do composite cone volcanoes look like?
steep sides with layers of dust, ash and tephra
What do shield volcanoes look like?
flatter profile and layers of solidified magma
What type of lava erupts from composite cone volcanoes?
sticky lava
What type of lava erupts from shield volcanoes?
runny lava
Where are composite volcanoes found?
destructive
compressional
Where are shield volcanoes found?
constructive
hot spots
What type of volcanoes are more explosive?
composite
How far does lava travel from composite volcano?
2500m +
How far does lava travel from shield volcano?
5000m +
How are composite volcano shaped?
steep sided
contained
conical
How are shield volcanoes shaped?
flat
wide
long
What are volcanic gases?
released into atmosphere
- change global temperature
- fatal high concentrations
What are landslides?
section of volcano falls down side of mountain
What is lahar?
mixture of volcanic ash, rocks and debris with water
- destroy towns and move too fast to outrun
What is lava flows?
eruptions of molten rock from deep within
- slow and sticky OR
- runny and fast
What are pyroclastic flows?
mixtures of hot, dry ash, rock and gas from volcanic eruptions
- 80km per hour
- 200 to 700 degrees C
What is tephra?
anything blown from volcano into air
- ash particles to chunks of rock
What is jokulhlaup?
glacial outburst, glacier melts due to volcanic eruption
What are primary effects?
immediate impacts of eruption or ground shaking
What are secondary effects?
as a result of pimary effects
Give a social primary effect relating to people
people injured or killed by collapsed buildings or pyroclastic flows
Give a social primary effect relating to infrastructure
infrastructure broken - water, gas, electricity
What is affected by primary effects?
people
infrastructure
transport
buildings
Give a primary effect relating to transport
roads, railways, ports and airports damaged
Give a primary effect relating to buildings
buildings and bridges collapse
homes destroyed
Give a secondary effect relating to buildings
homelessness causes people to die from exposure
Give a secondary effect relating to transport
blocked transport hinders emergency services causing further casualties
How is business reduced a secondary effect?
unemployment increases
economy slows
money spent on repairing
What natural secondary effects come after an earthquake?
landslides
tsunamis
Give a secondary effect relating to disease
lack of clean water and proper sanitation means disease spreads
Give a secondary effect relating to tourism
tourists put off
When did the Iceland eruption happen?
2010
What type of plate margin is Iceland on?
constructive / divergent
Describe the location of Iceland
Atlantic ocean, between Eurasian and North American plate
What two plates is Iceland spread across?
Eurasian
North American
Where is Eyjafjallajokull located?
South coast on constructive/divergent boundary
Why does Iceland experience tectonic hazards?
constructive / divergent boundary
hotspot
How far is Iceland volcano from Reykjavic?
160km South of Rejkjavic
When did the Iceland eruption occur?
15 April 2010
What did the Iceland volcano cause for Europe?
ash cloud
How far away were people affected by volcano in Iceland?
100km east affected
How much volcanic material was produced in five days from Iceland volcano?
140 million cubic metres of volcanic material
What was the Iceland volcano’s volcanic explosivity index?
4 on volcanic explosivity index
What was the process of the eruption of volcano in Iceland?
magma ejected hit cold air and solidified as dust particles
How thick was the ice cap that melted on the Iceland volcano?
150m thick ice cap
What were the primary effects of Iceland volcano?
ice cap melted
ash cloud
How many visitors go to London by air per day?
30,000 visitors per day by air
How much do visitors to London normally spend?
£17 million per day
How much did 6 day disruption cost London?
£102 million for delay
What did ash cloud from Iceland volcano cause?
6 day delay in air travel in London
How much did hotel occupancy decrease by in London during ash cloud delay?
decreased by 25%
What were the secondary effects of Iceland volcano?
flights cancelled
6 day delay
travellers trapped
livestock lung problems
How many European flights were cancelled due to Iceland volcano?
950,000 flights cancelled
What were immediate responses to the Iceland volcano?
families evacuated
animals moved to barns
trenches dug
Why were trenches dug as an immediate response?
allow flood water
How many farming families were evacuated in Iceland volcano as a immediate response?
20 farming families evacuated
Where is L’Aquila?
Italy
Where is Gorkha?
Nepal
When did the earthquake occur in L’Aquila?
6 April 2009
When did the earthquake in Gorkha occur?
28 April 2015
What was the L’Aquila earthquake on the ritcher scale?
6.3 on ritcher scale
What was the Gorkha earthquake on the Ritcher scale?
7.8 magnitude
Give examples of immediate responses relating to people
issue warnings
rescue teams
treatment
Give example of immediate responses for environment
extinguish fires
recover bodies
Give examples of immediate responses for destroyed buildings
provide shelter food and drink
What do rescue teams aim to do?
search fo survivors
Give examples of secondary responses for destroyed buildings
repair and rebuild infrastructure
improve regulations
restore utilities
Give examples of secondary responses for people
resettle locals elsewhere
install increased monitoring technology
Give examples of secondary responses for economy
develop opportunities to recover economy
How many people were killed in the L’Aquila earthquake?
308 killed in L’Aquila
How many people were killed in the Gorkha earthquake?
8,841 killed in Gorkha
How many people were injured in L’Aquila?
1,500 injured in L’Aquila
How many people were left homeless in L’Aquila?
67,500 people left homeless
How many buildings collapsed in L’Aquila?
between 10,000 and 15,000
Give examples of primary effects in L’Aquila
deaths/injuries
homelessness
buildings destoryed
How much economic damage did L’Aquila do?
$11,434 damage
Give examples of secondary effects in L’Aquila
landslides/rockfalls
mudflow
house prices increased
city centre cordoned off
What caused a mudflow in L’Aquila?
burst water pipeline near Paganio
What effect did cordoning off city centre have on L’Aquila?
business reduced
How many people injured in Gorkha?
16,800 injured in Gorkha
How much economic damage was done in Gorkha?
$5 billion damage
Give examples of buildings destroyed in L’Aquila
National Museum
Porta Napoli
L’Aquila University
San Salvatore Hospital
How many people were left homeless in Gorkha?
1 million left homeless
How many buildings were destroyed in Gorkha?
7,000 schools destroyed
26 hospitals destroyed
Dharahara Tower
What happened at international airport due to Gorkha earthquake?
congested as aid arrived
How many schools were destroyed in Gorkha?
7000 schools
How many hospitals were destroyed in Gorkha?
26 hospitals
Give examples of primary effects in Gorkha
deaths / injured
homeless
buildings destroyed
airport congested
What are the primary effects of an earthquake?
buildings destroyed
deaths / injuries
transport infrastructure damaged
pipes and electric broken
What are the secondary effects of an earthquake?
business reduced
economy slows
emergency services delayed
fires started
diseases spread
What causes fires to start following an earthquake?
broken gas pipes and fallen electricity cables
What are the primary effects of a volcano?
buildings destroyed
air travel halted
water contaminated
What are the secondary effects of a volcano?
economy slows
ice melts
tourism increases
fertile farm land
emergency services struggle
What are the secondary effects of Gorkha?
landslides / avalanches
tourism declines
rice seed ruined
What did Gorkha earthquake cause on Mount Everest?
landslides and avalanches killing 19 people
What happened to rice seed in Gorkha?
ruined
- income lost
- food shortages
How many people were given hotel rooms in L’Aquila?
10,000 sheltered in hotels
How many people were given tents in L’Aquila?
40,000 tents given out
How many dog units were sent to look for survivors in L’Aquila?
7 dog units
What bills were suspended in L’Aquila?
mortgages and Sky TV bills suspended
What happened to mobile calls in L’Aquila?
free mobile calls
How much money was raised for L’Aquila by EU Solidarity Fund?
$552.9 million from EU Solidarity Fund
What were the immediate responses for L’Aquila?
shelter provided
rescue team
bills suspended
money raised
What were the long term responses for L’Aquila?
torch lit procession
no taxes
students fees reduced
guilt verdict overturned
What happens annually in L’Aquila?
torch lit procession with Catholic mass
When did residents not have to pay tax in L’Aquila?
2010 no tax for residents
How were students fees reduced in L’Aquila?
university fees waived
free transport
When did the guilty verdict for manslaughter get overturned?
2014 guilty verdict overturned for 6 scientists
What were the immediate responses in Gorkha?
international aid requested
rescues
shelter
field hospitals
Facebook feature
How many tents were provided in Gorkha?
500,000 tents provided in Gokrha
What did UN and WHO send to Gorkha?
medical supplies
What were set up in immediate response to Gorkha?
field hospitals
What did Facebook launch as an immediate response to Gorkha?
safety feature for uses to indicate safety
What were the long term impacts of Gorkha?
aid money
landslide material cleared
building regulations
Mount Everest
How much money was given as aid money to Gorkha?
$274 million
What happened to lakes and rivers following Gorkha?
cleared of landslide material
What happened to building regulations in Gorkha?
controls enforced
What happened to Mount Everest following Gorkha?
new routes opened by August 2015 and permits extended by 2 years
What does building density cause differences in?
effects
What does construction standards cause differences in?
effects
What does corruption cause differences in?
responses
What do hazard prone areas cause differences in?
effects
What does magnitude cause differences in?
effects
What does monitoring/prediction causes differences in?
responses
What does medical facilities cause differences in?
responses
What does population cause differences in?
effects
What do resources and finances cause differences in?
responses
What do secondary effects cause differences in?
effects and responses
What does time cause differences in?
effects
What does emergency services cause differences in?
responses
What does transport cause differences in?
responses
What does type of plate margin cause differences in?
effects
What reasons for variation are influenced by wealth?
construction
corruption
monitoring
medical
finances
emergency services
transport infrastructure
What reasons for variation are not influenced by wealth?
building density
hazard prone area
magnitude
population density
secondary effects
time
plate margin type
How many people lived on or close to volcanoes in 2000?
500 million people
How many are estimated to be living by volcanoes in 2025?
600 million people
How many people live in Naples, Italy and what volcano are they near?
961,000 people at foot of Mount Vesuvius
Why do people choose to live at risk from tectonic hazards?
advantages outweigh the risks
What is the most important reason as to why people choose to live at risk from tectonic hazards?
cannot afford to move away
What is another important reason as to why people choose to live at risk from tectonic hazards?
large settlements with job opporunities
Give an example of a large settlement on a seismic area
San Francisco
What is the GDP of the Bay Area?
$535 billion
Where does Bay Area rank in comparison with national economies?
19th in world
What is a final important reason as to why people choose to live at risk of tectonic hazards?
engineering gives confidence to people
Give an example of engineering that is earthquake proof
Bird’s Nest stadium in Beijing
What are some economic reasons for living at risk of tectonic hazards?
geothermal energy
nutrient rich soils
mining / tourism
cheaper to stay
How much of world’s population lives near a volcano?
8% of world’s population
How many Americans live near earthquake prone area?
50% of Americans
What are some social reasons for living at risk of tectonic hazards?
friends and family
don’t understand risk
confidence in engineering
Why does monitoring, prediction, planning and protection differ in each country?
economy of country
location of country
Which is most important out of prediction, protection or planning?
planning - know what to do
How does monitoring work with volcanic eruption?
tiltmeters - shape of ground
thermal heat sensors - temperature
gas trapping bottles - radon/sulphur
How does prediction work with volcanic eruption?
advance warning before erupting
How does protection work with volcanic eruption?
evacuation plans
How does planning work with volcanic eruption?
evacuation
exclusion zones
education
first aid training
How does monitoring work with earthquake?
seismometers and GPS
radon detecting devices
Does prediction work with earthquake?
extremely difficult to predict
How does protection work for earthquakes?
building/infrastructure design
sea walls for tsunamis
How does planning work with earthquakes?
practice drills
emergency supplies
securing objects/furniture
