HAZARDS Flashcards
examples of atmospheric hazards…
hailstorms lightening tropical storms hurricanes tornadoes
examples of sesimic hazards…
tsunamis ground shaking fault ruptures lateral spreading liquefaction seiches
other geological/hydrological hazards…
debris avalanches expansive soils landslides rockfalls submarine slides subsidence
hydrologic hazards…
river flooding coastal flooding desertification salinization drought
volcanic hazards…
pyroclastic flows mud flow lava flow gasses tephra projectiles
wildfire hazards…
savannah
forest
grass
brush
what is adaptation?
the attempts of people or communities to live with hazard events
what is fatalism?
people cannot influence or shape the outcome therefore nothing can be done to mitigate against it
what is fear?
the perception that people will feel so vulnerable to an event that they will no longer be able to face living in the environment
what are primary impacts?
the effects of a hazard event that result directly from the event
what are secondary impacts?
the effects that result from the primary impact of the hazardous event.
what is a hazard?
the threat of substantial loss of life, substantial impact upon life or damage to property that can be caused by an event
what are natural hazards?
events which are perceived to be a threat to people, the built environment and the natural environment
what is a disaster?
a disaster occurs as a result of a hazard
common characteristics of natural hazards…
clear origins and distinctive affects
little or no warning
exposure to risk may be involuntary
the scale and impact requires an emergency response
what is perception?
the way in which an individual or group views a hazardous event
factors which influence the perception of hazards…
family situation past experiences socio-economic status employment status religious, cultural background
what is resilience?
the ability to use available resources to be able to respond and withhold the effects of a natural hazard
hazard incidence?
the larger the hazard the more human response would be needed
intensity?
the higher the intensity the more management strategies would be needed.
distribution
refers to the spatial coverage of the hazard
frequency
refers to the distribution of the hazard through time
magnitude
assesses the size of the impact
what is the structure of the earth?
inner core
outer core
crust
mantle
what are the two internal energy sources of the core?
primordial heat
radiogenic heat
what is primordial heat?
left over heat from the earths formation
what is radiogenic heat?
produced by the radioactive decay of isotopes
how many tectonic plates is the earths crust separated into?
12
what is Wilson’s theory about hotspots?
in certain locations around the world volcanism has been active for very long periods of time
this could only happen if relatively small long lasting hot regions called hotspots existed below the plates
what are examples of hotspots?
african plate
iceland
the azores
galapogos islands
describe the global distribution of active volacnoes?
located in long chains along destructive and constructive plate boundaries. The mid atlantic ridge and the pacific ring of fire are examples of where volcanoes are in chains.
what is an active volcano?
a volcano which has erupted recently
what is a dormant volcano?
a volcano which has erupted in the last 2000 years but not recently is dormant
what are are extinct volcanoes?
a volcano which is unlikely to erupt ever again
what is lava?
magma above the surface
what is magma?
molten rock underneath the surface
what are the three types of lava?
basaltic flows
andestic flows
rhyolites
what is being done to predict volcanoes?
ash fall meters strain sensors gps electrical field sensors gas sensors water flow satellites infrasound devices
what is mitigation?
any action taken to reduce or eliminate the long term risk to human life and property from natural hazards
what are prevention methods?
warn the population
evacuate
produce hazard maps
what are primary volcanic hazards?
ash lava flows nuees ardentes pyroclatic events tephra volcanic gasses
secondary volcanic hazards?
acid rain climate change lahars landslides flooding tsunamis
what are primary waves?
waves move the fastest - can move through solids liquids and air
what are secondary waves?
they can only move through solids
what are tsunamis?
giant sea waves generated by shallow focus underwater earthquakes involving movements of the sea bed
how are tsunamis formed?
rapid movement of the ocean floor displaces a column of water
a series of waves travels outwards at heights believed to be less than 3 feet on the ocean floor
as a wave approaches land, it’s energy compresses into a smaller space forcing it to gain height.
what are mitigation against a seismic hazard?
hazard resistant structures education fire prevention emergency services land use planning insurance aid tsunami protection
Describe the distribution of tropical storms?
form along the equator
get them between 5 and 20 north and south of the equator
once generated they tend to move westwards
what are the conditions needed for a tropical storm?
ocean temp of 27 degrees ocean depth of at least70m 5 degrees north or south of equator low level convergence air atmospheric instability latent heat and moisture supply
what is the scale for measuring the magnitude of TS?
the saffir simpson scale
social impacts of tropical storms?
death and injury waterborn diseases looting insurance premiums may rise stress and trauma
economic impacts of tropical storms?
repairing the damage properties damaged people become homeless crops damaged oil prices may rise businesses close
environmental impacts of a tropical storm?
sea fish may be killed as a result of a storm surge flooding landslides mudslides damaged ecosystems
what can be done to predict tropical storms?
geostationary sattelites
24hr surveillance by aircraft of storms that are likely to become hurricanes
allows time for evacuation
protection methods when tropical storms occur?
evacuation emergency services on full alert drills heavier roofs mitgation
what determines the severity of a hazard?
duration magnitude predictability regularity frequency speed of onset spatial concentration areal extent number of hazards
what is risk?
the exposure of people to a hazardous event presenting a potential threat to themselves
what is vulnerability?
geographical conditions that increases the susceptibility of a community to a hazard
why do people put themselves at risk?
hazard events are unpredictable
cost/benefit
lack of alternatives
changing the level of risk
what does the hazards of place model show?
the risk and vulnerability and the factors that contribute to it.
what is perception?
the way in which an individual or group views the threat of a hazard event
what are the factors that influence the perception of hazards?
family situation socio-economic satus level of education employment status religion,cultural background personal values past experience
what is HIC?
high income country
what is LIC?
low income country
what is relief?
the immediate local and possibly global response in the form of aid, expertise and search and rescue
what is rehabilitation?
a longer phase lasting weeks/months when infrastructure and services are restored
what is reconstruction?
Restoring to the same or better quality of life as before the event took place.
what can you do pre-disaster?
risk management
mitigation/prevention
preparedness
what can you do as a response to a disaster?
warning/evacuation saving people providing immediate assistance assessing damage ongoing assistance
what can you do post-disaster?
reconstruction
ongoing development activities
economic and social recovery
what does the disaster/risk management cycle show?
shows the ongoing process by which governments businesses and society plan for and reduce the impacts of disasters.
what did the theory of plate tectonics help us to understand?
the distribution of the worlds major land forms
where natural hazards can strike
the distribution of minerals and energy supplies
when does a destructive plate margin occur?
occurs when an oceanic and continental plates moves together. the oceanic plate is forced under the continental plate (lighter)
what do you get at destructive plate margins?
cone compisite volcanoes
fold mountains
ocean trenches
conservative plate boundary?
A conservative plate boundary, sometimes called a transform plate margin, occurs where plates slide past each other in opposite directions, or in the same direction but at different speeds.
Friction is eventually overcome and the plates slip past in a sudden movement. The shockwaves created produce an earthquake.
constructive plate margin?
A constructive plate boundary, sometimes called a divergent plate margin, occurs when plates move apart. Volcanoes are formed as magma wells up to fill the gap, and eventually new crust is formed.
what are deep sea trenches?
- mark where one plate begins to desend between the other
- found at two types of destructive plate margins
- oceanic and oceanic
- continental and oceanic
- the subducting of the denser oceanic plate forms a very deep part of the ocean known as an ocean trench.
what is an island arc?
- as the oceanic plate desends the heat and friction begins to melt the plate in the part of the subduction zone known as the benioff zone
- magma that is less dense rises forming volcanoes
- if the eruption takes place offshore a line of volcanoes known as an island arc can appear
what are rift valleys?
- form in continental areas due to fracturing of brittle crust.
- areas of crust drop between the paralell faults to form this feature
formation of tropical storms…
- the sun sends incoming solar radiation to the earth which warms our oceans
- this warms this oceans to a critical 27 degrees
- the high sea temp causes the warm moist air to rise from the ocean
- the evaporated air cools as it rises condesing to form towering thunderstorm clouds
- as the air condenses it releases heat which powers the storm and draws up more and more water from the ocean
- several smaller thunderstorms join together to form a giant spinning storm
- the storm develops an eye at the center where air desends rapidly. the outer edge pf the eye wall is where the strongest winds occur
- as the storm is carried accross the ocean by prevailing winds it continues to gather strength from the warm moist air.
why does management vary in HIC’S and LIC’S ?
poorer countries cannot support themselves
HIC’S can have better protection methods resources and information
lack of education in LIC
HIC’S have more money
what is a wildfire?
the term used for an uncontrolled fire fueled by natural vegetation
when do fires occur?
when oxygen combines with carbon, hydrogen and other organic materials in a rapid chemical reaction.
what are the 3 main types of wildfires?
surface fires
ground fires
crown fires
conditions needed for a fire?
fuel-dry vegetation
ignition source
climatic/weather condition
natural causes of wildfires…
wood much reach 300 degrees hot volcanic lava earthquakes lack of precipitation lightening strike meteorites very dry vegetation
human causes of wildfires…
power lines guns increase in human activity campfires not disposing of cigarettes properly arson burning debris accident or equipment failure
what do the natures of wildfires depend on?
types of vegetation space between fuels wind strength topography times and seasons temperature
what are the primary environmental impacts of wildfires?
destruction of habitats and ecosystems
death and injury of animals
short term surge of Co2 due to burning of fossil fuels
atmospheric pollution
what are the primary social impacts of wildfires?
loss of life and injuries
displacement of people
disruption to power supplies
damage to mobile phone lines
what are the primary economic effects of wildfires?
damage/destruction of infrastructure
financial losses
destruction of businesses
loss of crops and livestock
what are the primary political impacts of wildfires?
actions of emergency services
responses of local and national government
pressure on local authorities and emergency services
what are the secondary environmental impacts of wildfires?
lack of trees and vegetation
increased carbon emissions have an impact on climate change
effects on ecosystem development
temporary changes to weather
what are the secondary social impacts of wildfires?
possible need for new employment
behavioural adaptations based on wildlife experience- people have to abide by new rules and regulations
what are the secondary economic impacts of wildfires?
cost of rebuilding or possible relocation
replacement of infrastructure
cost of future preparedness and mitigation strategies
tourism can be affected
what are the secondary political impacts of wildfires?
develop strategies for prepardness and mitigation
desicions about replanting forests
what is the prepardness strategies for managing wildfires?
- rural firefighting teams staffed by volunteers
- warning released through social media
- fire bans introduced
- a red flag warning issued when weather conditions are extreme
what are the prevention strategies for managing wildfires?
-public awareness in campsites and public areas where rules regarding the use of campfires and barbeques have to be strictly enforced
“fire bans” during times of high risk
what are the mitigation strategies for managing wildfires?
- cameras,infrared sensors and sattelites can detect thermal radiation
- NASA is developing drone technology
- disaster aid and fire insurance
what attitudes have the people of the phillipines taken to living in a multi-hazardous environment?
implemented management strategies
trained volunteers in disaster management
have co-operative partnerships with the government
willing to adapt
