Hazards Flashcards
what is a hazard by definition?
potential threat to human life and property caused by an event.
what is a natural disaster?
when a vulnerable population is exposed to a hazard
who’s model represents hazards and disasters?
Degg’s model
what are the three main types of geo hazard?
geophysical- land processes
atmospheric- atmospheric processes- weather
hydrological- water bodies and movement
what are hazards that are both atmospheric and hydrological?
hydrometeorological hazards
what can cause people to have different viewpoints of how dangerous hazards are and what risk they impose?
- lifestyle
- £
- cultural
how can wealth effect affect how a person might perceive a hazard?
wealthier people may perceive a hazard to be smaller as they are less vulnerable. yet they may also see the risk as greater as there is more risk of property damage and financial loss.
how can experience affect someones hazard perception?
someone who has experienced more hazards more likely to understand full effects of hazards. OR have a ‘lightening never strikes the same place twice’ mindset
how can education affect someones hazard perception
?
A person who is more educated about hazards may understand their full effects on people and how devastating they can be and have been in the past.
how can religious beliefs affect someones hazard perception?
Some may view hazards as put there by God for a reason, so may not perceive them to be negative.
how can mobility affect someones hazard perception?
Those who have limited access to escape a hazard may perceive hazards to be greater threats than they are
what is fatalism?
- uncontrollable natural events
- any losses should be accepted
- nothing that can be done to stop them
“what ever happens happens”
what are 5 active responses to hazards?
RAMMP
- prediction
- adaption
- mitigation
- management
- risk sharing
what is prediction?
using scientific research and past events to know when a hazard will take place, send out warnings, impacts reduced
what is adaption?
attempting to live with the hazards by adjusting lifestyle choices so vulnerability is lessened
what is mitigation?
strategies carried out to lessen the severity of hazard
what is management?
coordinated strategies to reduce a hazards effects. includes (prediction, adaption, mitigation)
what is risk sharing?
community preparedness, community shares risks, invests collectively to mitigate the impacts of future hazards
give a case study of where risk sharing has worked?
New Zealand- Multi hazard environment (earthquake, volcano, tsunami), Canterbury hazard cost 20% of national GDP, now risk share by insurance investment so strategies can be put in-place before the disaster.
what is incidence?
frequency of a hazard, not affected by strength
what is an issue with low incidence hazards?
harder to predict and have less management strategies put in place = more catastrophic.
some characteristics of low incidence hazards?
- usually more catastrophic/ intense, only 36 earthquakes since 1500 were a magnitude of 8.5+ but millions of earthquakes that are too weak to be recorded.
what effects will have high magnitudes, high intensity hazards have?
worse effects require more management
are magnitude and intensity interchangeable?
NO
why are magnitude and intensity not interchangeable?
the magnitude is usually definable and can be a number- THIS DOES NOT CHANGE.
Intensity is effects on a person and can change dependent on distance from hazard or management strategies
how level of development effect how a place reacts to a hazard?
LIC= less effective mitigation strategies= efforts= more catastrophic
HICS that are less prepared= lack of management strategies
case study for a HIC not being prepared for a hazard?
Canada, where wildfires have been increasing less money and resources have been available for earthquake and tsunami preparation. even detailed Evacuation routes and tsunami siren are not available in pop tourists beaches such as Vancouver island. Text message systems are available tho.
what is the pate tectonic theory?
the lithosphere us broken up into large slabs of rock called tectonic plates
why do the plates move?
due to convection currents in the asthenosphere, which push and pull plates in different directions. convection currents are caused when less dense magma rises, cools, then sinks
what are the three types of plate boundaries?
constructive (away from each other)
destructive (towards each other)
conservative (parallel to each other)
what land forms are created at constructive (continental)
- rift valleys
- earthquakes
- volcanoes
what land forms are created at constructive (oceanic)
- ocean ridges
- earthquakes
- volcanoes
what land forms are created at conservative plate boundaries?
earth quakes
what land forms are created at destructive (continental)
- fold maintains
- earthquakes
what land forms are created at destructive (oceanic)
- ocean trenches
- island arcs
- earthquakes
- volcanoes
what land forms are created at destructive (continental/oceanic)
- fold maintains
- volcanoes
what are destructive plate boundaries?
oceanic crust sub-ducts under the continental plate. leaves a deep ocean trench.
what are the three different types of destructive plate boundaries?
continental and oceanic
oceanic and oceanic
contiental and conteinetal
what are the two types of plates at constructive plate boundaries?
oceanic and oceanic
continental and continental
what are two forces that inflencent how convergent boundaries occur?
rideg push
slap pull
what happens at a conservative plate boundary?
- parallel plates move in different directions
- the oceanic crust movement can displace a lot of water
- continental crust, fault lines occur where the ground is cracked by movement.
what are hotspots?
areas of volcanic activity that are not related to plate boundaries. Hot magma plumes from the mantle rise and burn through weaker parts of the crust. create volcanoes and islands. plame stays in same place but plates continue to move with sometimes cause a chain of islands
what happens on plate boundaries where volcanoes form?
plates melts and magma erupts through plate
name three hazards associated with volcano eruptions? LMT
lava flows- silica makes lava viscous and slow, common inn explosive eruptions
mudflows- caused by ice melting at high latitudes
tephra - any type of rock that is ejected by a volcano
what is the ring of fire?
an area of high volcanic and earthquake activity located in the pacific and the majority of large volcanoes occur within 25,000 mile belt
what is vulcanicity measured in?
volcanic explosivity index (VEI)
what are intense high magnitude eruptions known as?
explosive
what are calmer, lower magnitude eruptions known as?
effusive
what are the three classifications of volcanoes known as?
active, dormant or extinct