1
Q
Black Saturday
A
7th February March 14th 2009
Series of fires that started over the course of a months
Causes
- area covers in eucalyptus which ignites easily aiding the fire explosive flammable fuel
- temperature peaking at 45.1 degrees C
- V low humidity
Heatwave and drought causes by El Niño and Indian Ocean Dipole
Impacts
- Kinglake fire = largest of many fires burning on Black Saturday destroying 1,800 houses
- 173 does
- 7000 displaced from homes
- 4.4 billion USD damage
- looting happened to abandoned properties
Mitigation and response
- More than 4,000 firefighting personnel mainly from CFA deployed
- bush fire appeal raised over 350 million USD
- fire breaks, bulldozing vegetation to break course of flames
- offered families therapy to deal with trauma
- replanted trees in burnt down areas (helps stabilise hills and prevent mud slides
- Aus gov released ‘rebuilding together’ scheme to replace major facilities damaged in the flames
- 80 millions relief funding over next 30 years from Aus government
Prevention of future fires
- can’t prevent natural hazard (debatable global warming)
- controlled managed burning= less dead dry vegetation but disrupts ecosystems
- public awareness ‘smokey bear’ educated people about leaving bbqs and campfires unattended to
- fire ban at times of high risk
2
Q
Example of earthquake ? Poor
A
Hati
- 13th Jan 2010
- in Caribbean
- lies between two fault zones, conservative play boundary (NA plate and Caribbean plate)
- fatalistic perception
- 70% live on 2 dollars or less a day
- life expectancy in Hati
- 7 on Richter scale
- epicentre 25km of Port au Prince
- 52 after shocks above 4.5
Perception
- fatalistic
- 86% live in slums
Cause
- Epicentre close to capital
- few earthquake resistant buildings
Primary impacts
- 220,000 dead
- several hospitals collapsed
- airport damaged
- businesses destroyed
- gas mains ruptured
secondary impacts
- 1 in 5 lost their jobs
- 1.3 homeless
- morgues overflowed with dead bodies = contamination in street of Hati= cholera outbreak
- aid obstructed as airport damaged
- many months later cholera outbreak and has killed 10,000 since event
Primary responses
- emergency rescue teams from Iceland
- 8000 temporary field hospitals set up by Red Cross
- UN troops and police sent to help distribute aid
- 100 mill given by USA
Secondary responses
- money pledged by organisations and governments but slow progress
- but after 1 year
1 mill still without a home
Cash for work programmes, still rubble
Schools being rebuilt and teachers trained
3
Q
Volcanic activity example ?
Eyjafjallajokull
A
Iceland
On huge fissure
- on a Atlantic ridge
- April 2010
- constructive divergent plate boundary
- 4 VEI scale
Causes
- 2 bodies of magma meeting
Primary impacts of eruption
- ice cap melted on volcano = mass flooding
- pyroclastic flows
- interaction of water and gas= explosive plume of gas + volcanic ash caught in high altitude winds 10km high then carried south east
- deaths
- destruction of main roads
Secondary impacts of eruption
- air spaces in Europe which meant all air space shut down temporarily
- 100,000 flights cancelled effected tourism and trade
- 25% increase in respiratory illness across Iceland
- 11% decline in tourism following eruption
- fertile soils reported record yields following year
- coach and cruise ship companies benefited helping get people home
Primary response
- due to constant monitoring of the volcano sites the IVO suggested all people on the southern coastal towns be evacuated
- live stock moved
- sections of embankment deliberately breached to allow flood water to run to the sea and preventing expensive bridges being destroyed
- successful response as no one lost their lives
Secondary responses
- had to import more food as large areas of land not fit for agriculture
- ‘future volc’ improves technology and sensors so Icelandic officials be prepared in event of another eruption
- rebuilding damaged infrastructure
- Eyjafjallajokull = no popular tourist site= brings thousands in
- air fares increase to recoup losses
- families had to temporarily relocate
- research aims to improve forecast methods
4
Q
Tropical storm example ?
HIC
A
USA Hurricane Katrina
Formed 200 miles SE of Bahamas
Caribbean sea around 28*c
-intensified to category 5 exceeding wind speeds of 175mph
-late August hit New Orleans
New Orleans
-high density population due to urbanisation
Advances warning given out on 26 August
- mayor or New Orleans ordered city be evacuated shortly after Kathrine was upgraded to cat 5
Primary impacts
Storm surge hitting Louisiana 10m high Desiree’s gulf coast
- more than 1 million became refugees
- demolished 30 oil platforms
- effected breeding grounds of endangered species e.g brown pelican
- Louisiana super Dome overcrowded, capacity 800 and 30,000 showed up= rape and crime
- 1.8 k died= low death toll as USA has good infrastructure
Secondary impacts
- refugees still in all 50 states
- racial tensions exposed
- oil prices rose, uk petrol increase by £1 per litre
- 200 billion USD damage
- businesses failed as couldn’t pay for damages
Primary responses
- most population left in cars
- 150 thousand remained, mainly by choice and arguably poorer who may not have had home insurance (illustrates how behaviour responses are determined by potential economic losses
- 1.8 billion donated to American Red Cross
- troops sent out to keep law and order
- Louisiana super dome offered as shelters
Secondary responses
- state criticises for poor effort for planning for event
- most effected by Katrina of black ethnicity and urban dwellers (poorest and most disadvantaged) in American society
- alleged authorities would have responded differently had it been white people majority effected by Katrina
5
Q
What is a hazard
A
Threat of substantial loss of life that substantially impacts life and property that’s caused by an event either naturally caused or through humans
6
Q
What is a disaster?
A
Is a result of a hazard, e.g living on a fault line= hazard but the earthquake effecting property and people is a disaster
7
Q
What is a risk?
A
Exposure of people to hazardous event presenting a potential threat to themselves
8
Q
Vulnerability ?
A
Potential for loss
9
Q
Mitigate ?
A
Any sustained action to reduce/ eliminate risk of life/ property
10
Q
3 types of hazard ?
A
Geophysical- driven by earths internal energy
Atmosphere- driven by processes in the atmosphere
Hyrdrological- driven by water bodies
11
Q
Common features of hazards ?
A
- origins clear
- allow short earning before event
- requires emergency response
- results in loss of life
12
Q
Resilience?
Capacity?
Community preparedness?
A
Resilience- ability of communities/ individuals to respond/ recover effects
Capacity- resources and strengths within a community that help them withstand/prepare for mitigate/ prevent/ recover from natural disaster
Community- prearranged measures that aim to reduce the loss of life and property damage through e.g education and food and shelter supplies
13
Q
Explain the hazard management cycle ?
A
- illustrates the process which governments plan for and reduce the impact of natural disasters, following stages correctly results in greater future preparation and practical action company used this model
4 sections of the cycle?
(2 pre-event, 2 post event)
- preparedness, education and awareness can reduce human causes and adjust behaviour to minimise likely impact of a hazard
- response, speed of a response depends on effectiveness of emergent plan put in place
- recovery, restoring affected area to something approaching normal
Mitigation, actions aimed at reducing the severity of an event
14
Q
Describe park impact response model
A
Describes 3 phases following a hazard
Relief
- immediate response in form of aid, expertise, search and rescue
Rehabilitation
- infrastructure restored temporarily to allow construction phase to begin
Reconstruction
- restoring to same or better quality of life as before event took place, likely to include measures to mitigate against similar level of disruption of event occurs again
15
Q
2 types of plate ? And their characteristics?
A
Oceanic-
- basaltic rock, thinner but more dense
- 200 million yrs old
Continental
- granitic rock, thicker and less dense than oceanic
- 1.5 billion years old
- won’t sink into asthenosphere
16
Q
What’s the Mohorovic discontinuity
A
The sharp divide between the upper mantle and crust
17
Q
Lithosphere ?
A
Crusts and upper mantle where tectonic plates are formed
18
Q
Asthenosphere?
A
Upper part of mantle and below lithosphere
19
Q
What causes the earths magnetic field ?
A
Spinning of the outer core when the inner core rotates
20
Q
2 species of internal heat on our planet ?
A
Radiogenic- heat created by radioactive decay of isotopes
Primordial- heat left over from initial collision during formation of the the earth
21
Q
Evidence for continental drift as proposed by Alfred Wegener ?
A
Geological- minerals and striations match on different continents e.g Brazil and West Africa suggesting they were once pieces together
Climatological- glaciation in Africa, America and other countries all at same time around 300 millions years ago
Biological
- fossils of same species found in different continents separated by seas and plants e.g mesosaurus
22
Q
Criticise Alfred Wegener theory
A
- no mechanism for movement
- wind and currents could carry species of plants/fossils across seas
- theory wasn’t accepted by scientists at time
23
Q
Harry Hess’ plate tectonic theory ?
A
Studied age of rocks in Atlantic Ocean, confirmed newest rocks were in center of ocean and still being formed
(Said Atlantic ridge could be widening by 10cm a year)
24
Q
Strength of Harry Hess ?
A
We can measure plate movement through palaeomagnetism, scientists know the approx flip of earths magnetic field and using positions of the ions in the rocks we can find out the rate of movement in plates
25
3rd body of evidence for plate movement ?
US when testing nuclear weapons underground uncovered idea of rigid plates and set up network of seismic stations and produced a coherent theory of plate tectonics
26
What is ridge push ? As an alternative explanations for plate movement
Happens as constructive plate boundaries, upwelling at ocean ridges. Gravity abuses these ridges to slide down the moving plate
27
What is slab pull ?
At destructive plate boundaries gravity pullls the whole oceanic plate down = destructive subduction
28
What happens at oceanic continental convergence
Continental oceanic
Denser oceanic plate subducts under continental = oceanic trench e.g Peru Chile trench
-the continental land mass is uplifted and compressed creating fold mountains e.g Andes
- friction builds at Benioff zone, earthquake may release tension
- melted oceanic plate is less dense that surrounding magma and may find its way to surface through faults in oceanic plate = explosion be volcanic eruptions
29
What happens at oceanic oceanic
?
Convergence
Faster/denser plate subducts dcreatjng deep ocean trench, melting of oceanic plate = magma plumes = summarise volcanoes that may turn to island arcs e.g Mariana Trench and Mariana Islands
30
What happens at continental continental plate ?
Low density so subduction doesn’t occur, colliding plates create high food mountains e.g Himalayas
31
Rift valleys are ?
During continental divergence lithosphere stretches = fracturing into set of parallel fault lines
- land between these faults collapses into valleys e.g Great African Rift Valley
32
Mid-ocean ridges ?
Divergence at continental areas creates chain of sub-marine mountain ridges e.g Mid Atlantic Ridge, middle of ridges are marked by deep rift valleys
Valleys widened by rising nagana that cools and solidifies
- volcanic eruptions occur along ridges creating sub-marine volcanoes
33
Where are most tech tonic associated ?
95% world tectonics and volcanoes are located along plate margins e.g Pacific ring of fire
34
Explain how magma plumes are made ?
There may be concentrated radioactive decay in core creating hotspots around the core, hotspots heat lower mantle creating localised thermal currents where magma plumes rise vertically which occasionally happens in the centre of plates which then burns through the lithosphere = volcanic activity on the surface
The hotspot remains where it is, the movement of the overlying plate= formation of chain of active and subsequently extinct volcanoes e.g Hawaiian islands
35
Where are volcanoes common ?
Constructive plate boundaries and absent at conservative and some hits posts such as Hawaiian islands more than 3,300 km eats of nearest boundary
36
Magnitude of volcanoes, how are they measured
Measured on logarithmic scales from 0-8 called VEI
37
What is the frequency/regularity of volcanic eruptions ?
Can’t predict to a degree of accuracy
- volcanic periodicity seems random
Predicting
- seismometers and seismographs used to detect seismicity of coming eruptions then tell governments for planning and preparedness
- this can be aided by evidence from previous eruptions such as Lahar deposits, hazard maps can be produced to identify areas most at risk
Can’t rely on average volcanoes cycles e.g Vesuvius erupts in avarage every 70 years but erupted 6 times in the eighteenth century
- versuvius has only 2 weeks warming with 3 million people living within 15km to it
38
Primary impacts of eruptions ? And secondary
Lava flows and pyroclastic flows and ash
Lahars, flooding, volcanic landslides, tsunamis, acid rain (eruptions emits sufur which combines with atmospheric moisture) and climatic change through huge amount of debris in atmosphere having a global cooling effect
39
What are lahars and their causes ?
Volcanic ash mixes with water flowing downhill = volcano mudflows= most deadly volcanoes impacts
Caused by;
pyroclastic flows entering streams
And rapid melting of snow/Ice
40
What are fissure eruptions ?
Create huge lava plateaus
41
Type of lava in shield and composite volcanoes ?
Shield - runny lava (low viscosity)
Composite volcanoes- very viscous
42
How are shield volcanoes formed ?
Basalt runs down from crater and cools
43
How are composite volcanoes formed ?
When alternative eruptions of ash and tephra and lava build up volcanoes layers (destructive boundaries) rhyolitic lava
44
What are buses ardentes?
V hot gas and tephra mixed clouds that travel at a high velocity up to 700kmph
Pyroclastic flows
45
Causes of seismicity ?
Human
Fracking, mining, reservoir construction
Natural
- friction between plates builds stresses in lithosphere, stress builds up until rocks in plates fracture along cracks called faults sending a series of seismic shocks directly above (epicentre) the break in point (focus)
46
Type of shock waves/ seismic waves
Primary
- fastest and travel through whole earth like compressions
Secondary waves
- reach surface second, don’t travel all way through earth and shaped like a skipping rope
```
Surface waves (L)
- slowest waves, cause most damage up and down, side to side
```
Rayleigh
- radiate from epicentre moving up and down
47
Predictability of earthquakes ?
Can’t predict but can identify areas most at risk
Scientists identified a number of common events that occur before and earthquake;
Micro quakes, bulging of the ground, raised groundwater levels and curious animal behaviour
48
Mitigation against earthquakes ?
- infrastructure can be designed to withstand shaking, rolling weights on top, rubber shock absorbers between building and foundation, reinforced foundations
- geographic information systems used to prepare hazard maps showing areas at greatest risk, so prevent building plans there
- education can better prepare people for how to survive earthquakes e.g get under door ways
- contingency planning is possible
49
Mitigation for tsunamis ?
90% associated with seismic activity along Pacific Ring of fire
Pacific warning system based in Hawaii give many hours warning with floating boys as measures, and Japan sends out texts
50
Characteristic of a tsunami wave ?
Wave height around 1m out at sea but up to 25m in shore
- wave length= v long, up to 1000km
- travel up to 960kmh
51
What is the moment magnitude scale ?
A scale that’s applicable globally so preferred to Richter
- based on total moment release of earthquake (force and distance of fault moving)
- logarithmic scale
52
What is the mercalli scale ?
Uses observations of people who observed it to estimate intensity
- not as scientific
- subjective and damage doesn’t necessarily mean intensity
53
Primary and secondary impacts of earthquakes ?
Primary
- ground shaking
- infrastructures damages
- liquefaction of saturated soils
Secondary
- fires from broken gas pipes
- tsunamis
- disease spread from contaminated water e.g cholera in Hati
- education suspended= lost generation effecting economy
- buildings subside and kill people
54
Actors effecting impacts of earthquakes?
- Magnitude and depth of earthquakes
- distance from epicentre
- design of strength and buildings
- time of day
- population density, preparedness and education
55
Define tropical storm ?
Rapidly rotating storm system characterised by low pressure air and strong winds
56
Characteristics of TS?
- Extend to 500km in diameter
- have average wind speeds of 75mph
- cause extensive damage and loss of life
- most powerful part of storm = eye wall
57
What helps create a tropical storm ? And where are they distributed
- 20* north or south of the equator in the ICTZ where climate is hot and trade winds meet
- rotation of the planet (certain amount of spin needed o initiate characteristic rotating motion of a TS = coriolis effect and increased with distance from equator explains why storms don’t usually form 5 degrees n or s of equator
Atmospheric instability, T storms are more likely to form as warm air rising encourage their formation
- must be formed over oceans as need moisture
- overall prevailing wind to push them in one direction
58
How are TS formed ?
Warm air rises rapidly in the centre to be places by air drawn in the centre, replacing it = central vortex, the centre of the storm is often characterised by a column of sinking air
As air rises rapidly it creates cumulus nimbus clouds, when condensation occurs, latent heat is released which can effectively power the storm
59
Hazards associated with tropical storms ?
Strong winds
Storm surges- typically 3 in height which inundate agricultural land with sea water and pollute fresh water supplies
Coastal river flooding
- torrential rainfall can occur, excess of 200mm in a few hours = coastal flash flooding up to 1 billion in damage in New Jersey USA Irene
Landslides
- 90% landslides each year are caused as a result of heavy rainfall and many triggered by TS, weakening material cohesion and slope failure
60
Predictably of TS?
- hard to predict
- no from evidence TS are becoming the frequent
- know what times of year they are most common
- know the main areas at risk
- NOAA uses a number of factors to predict Amount of TS expected in a year
- hurricanes usually follow same course but we can’t rely on this
Return period can be calculated
- frequency at which a certain intensity hurricane can be expected within a given distance of a location
61
Reducing impacts of TS? Preparedness, mitigation, insurance ?!
Preparedness
- most living at risk of TS are aware of dangers associated with it through public awareness campaigns and education
- instructions provided on what to do in event of TS e.g plan emergency route and reinforce doors
- satellites and radars can track TS and predict likely routes
- National hurricane centre in Miami uses SLOSH to predict hurricane storm surges
Mitigation
- structural responses,
Can protect through soft engineering e.g planting trees and coral reefs maintained
- USA provides grant money to make home more resilient to hurricane and wind damage, less damage = less insurance claims
Disaster aid comes in 2 forms;
Immediate relief e.g search and rescue
Or longer term reconstructional aid
AID can come from trading blocs, NGOs and charities, longer term aid money may come as a loan
Insurance
- widely used to mitigate against effects of TS
- people encouraged to take out insurance in wind damage
- social issues arise regarding this as rich can afford high premiums and poor can’t = weird behaviour such as poor in New Orleans staying home to safeguard property
- people parking cars facing the wind as insurance only covers wind mirrors
Prevention
- cloud seeding attempted but not successful
- focus now on forecast and adaptation
Adaptation
- land use zoning (low value property at coast)
- Florida coastal properties raised in stilts and bottom floor usually garbage (adaptation of functionality of houses)
- Wind resistance buildings e.g Afyer Darwin in Australia
62
Mitigation of impacts of TS in Bangladesh ?
Boha cyclone killed 500,000
- TS monitored by Bangladesh meteorological department and warning issued over Tv and radio
- cyclone shelters built
- concrete cyclone shelters been constructed= safe refuge and school in meantime
63
Wildfire ?
Generic name for an uncontrolled fire
64
What is El Niño?
Affects global temps and flood and wildfires
This is what usually happens
- trade winds blow from east to west
- pushes warm water to western side of ocean by Australasia
- cold water replaces warm that’s been pushed away by upwelling (South America)
- hot water in West creates warm rising air = unstable weather conditions and more cloud and rainfall
- creates atmospheric circulation with hot air rising one side and cool air descending the other side
During El Niño
- trade winds are weakened and warm water is pushed to west and less upwelling
- allows usually colder parts of ocean to warm
- changes locations of winds and precipitation
- Increased flooding risk in east and west
- due to extreme ocean heating releases vast amounts of energy into atmosphere during these years global temps increase
La Niña
- increased standard situation I.e increase trade winds and push while systems west
65
Indian Ocean Dipole
Warm water pushed from east to west and cool upwelling occurs by Australia
- less cloud forms above Australia meaning less ran over Australia
- creates v dry hot conditions
66
Conditions favouring wildfires ?
- Ready field supply
- favourable climatic conditions (positive IOD and El Niño)
- topography of landscape (fire burns faster in slopes)
- vegetation type, (moisture content), flammability (eucalyptus are highly volatile and explosive)- fire promoting
Strong dry winds from deserts exacerbate drying process/ creates ideal conditions for lightning storms which is a common form of wildfire ignition
Wind strength
67
Human causes of wildfires ?
Campfires
| Discarded cigarettes
68
Natural causes of wildfires ?
```
Lightning,
Fire brands (burning vegetation carried by wind, igniting isolated parts of woodland
```
69
Environmental impacts of wildfires
Destruction of habitats and ecosystems, death and injury of animals l, atmospheric pollution from smoke
- ash washed into water ways
- short term surge of carbon m
- sandy soils turning glass like therefore increasing run off
70
Social impacts of wildfires ?
Loss of life and injury
- displacement
- destruction
- disruption to power lines and communications due to strong winds
71
Economic impacts of wildfires ?
Destruction of structures and business like schools, findnacial loss, loss of crops and livestock
72
Secondary impacts of wildfires ?
Lack of trees and vegetation
- increased flooding and leaching risk
- increased C emissions me global warming
- possible need for new employment
- behavioural adaptations
73
Mitigation of wildfires
Early detection thought infrared sensors and drone surveillance
- NASA developing drone technology
- ways of controlling fire
using natural or unnatural fire breaks to break course of fire
- disaster aid and insurance
74
What are the 4 strategies to managing wildfires ?
- Preparedness
- mitigation
- prevention
- adaption
75
Preparedness in managing wildfires ?
- Rural firefighting teams staffed by volunteers
- fire warning released at times of high risk through social media and fire bans may be issued
- extreme caution issues during times of red flag warning
- fire weather watch at times of caution
- people make fire breaks
76
Prevention in managing wildfires?
- Controlled burning reduced fire fuel but this can get out of control E.g fire line explosive to fell trees
- public awareness campaigns in what causes WFs e.g BBQ and campfires strictly enforced
- ‘smokey bear’ campaign, in America that 70% know his message and has reduced land lost to wildfires dramatically
77
Adaptation to wildfires ?
- Let them take their course, natural processes that reform ecosystems
- building houses in areas of low risk
- building houses out of cheap materials and eco friendly
- keeping wood away from the house
78
Christchurch ?
Deaths- 185
- 22nd feb 2011
- aftershock of earthquake from September
- 6.3 on Richter
- epicentre 6km from city
- 12:51
Causes
- fault line on subductive and conservative plate boundary
Impacts
- 40% buildings damaged beyond repair
- 20 billion USD economic damage
- Canterbury TV building completely collapsed
Secondary
- landslides, rugby World Cup has to be moved affective future economic influence
Short term
- immediate aid for people effected
- demolishing old city and at risk buildings
Recovery and redevelopment plan
2 strategies
1) main gov initiative to improve and redevelop Christchurch
- 20 billion damage so ‘roadmap to recovery’ creates to repair damages
- 6 working principles involving working together to rebuild the city e.g leadership, economic growth and built environment improvement
2) Christchurch central development plan
- designed to reconstruct central part of city
- wanted to create ‘thriving heart of the city’ drawing in heritage and embracing change
- locals offered 106,000 ideas e.g requests for shopping and cycling
- redesigned to attract people
- sustainable city with large social areas to encourage social interaction
79
Multi hazardous environment ?
- archipelago of 7,000 islands
- population 100 million
Location
- western rim of
80
Management in Philippines ?
Focus on response and a reactive approach when. They need to mitigate e.g land use planning
- bottom up approach needed
- PNRC with Red Cross organisations starting at community levels
Geography
flashcards
Decks in class (11)
# Cards
