Hazards Flashcards
What is a hazard?
A potential threat to human life/ property.
What is a natural hazard?
Caused by natural processes.
What is a man-made hazard?
Caused by human actions.
What is a disaster?
When a hazard seriously affects humans.
What is a risk?
Likelihood humans will be affected by a hazard.
What is vunerability?
How susceptible population is to damage caused hazard.
What are short term impacts?
Immediate effects of a disaster.
What are long term impacts?
Long lasting effects of a disaster.
What are short term responses?
Immediate reactions to emergency situations.
What are long term responses?
What is doneto restore the country.
What does mitigation mean?
To minimise the severity and impacts of a hazard.
What does exacerbate mean?
To make worse.
What is a geophysical hazard?
Caused by land processes. Examples= earthquakes, volcanic eruptions, landslides and tsunamis.
What is an atmospheric hazards?
Caused by climatic processes. Examples= tropical cyclones, storms, doughts, extreme weather, wildfires
What are hydrological hazards?
Caused by water movement. Examples= floods and avalanches
Hazard perception of a wealthier economic background…
Richer are able to afford to move to areas less prone to hazards or build homes to withstand hazards so perceive risk to be less smaller.
Hazard perception of those with an educated background…
More education= better understanding or risks= ability to mitigate
Hazard perception of those with a past experience of hazards…
If been affected before they are more likely to be concerned.
Hazard perception of those with different personality…
Some people fear whilst others find it exciting
Hazard perception due to religion…
Some view that God sent hazards as an act of God whilst others view that its sent to punish people.
What is a fatalistic perception of hazard?
It is inevitable so they accept the risk and stay where they are.
What is prediction?
Using available technology to predict and prepare for event. Examples= weather forecasts and seismic monitoring. Can lead to prevention.
What is adjustment/adaptation?
Implementing strategies to live with hazards. Example=earthquake buildings
What is mitigation?
Reducing impacts of the disaster. Example= sandbags in a flood
What is management?
Planned and coordinated responses for when it does happen.
What is risk sharing?
Being prepared by sharing the costs of reducing the damage done by a hazard with insurance.
What is capacity?
A combinaton of all strengths and resources avaialble within a community, soceity or organisation that can reduce the level of risk, or the effects of a disaster.
Risk Equation
(Frequency or magnitude of hazard(H) x Vunerability(V))/ Capacity to cope or adapt(C)
What does the ‘pre-disaster’ phase show in the Park model?
Shows the quality of life is ats its normal equilibrium.
What does the ‘disruption’ phase in the Park Model show?
During and directly after= destruction/damage and that people have not responded yet.
What does the ‘relief’(hours-days) phase show in the Park model?
Aftermath, rescue, saving people and preventing further damage.
What does the ‘rehabilitation’ phase(days-weeks) show in the Park Model?
That once the area is stable they can resolve long term problems such as shelter/aid for victims.
What does the ‘construction’ phase (weeks-years) show in the Park Model?
Rebuilding permanent features.
If reconstruction takes quality of buildings/infrastructure back to pre-disaster…
Normality resumes and vunerability stays the same.
If reconstruction takes quality of buildings/infrastructure to better than pre-disaster…
Area improves and vunerability decreases
If reconstruction takes quality of buildings/infrastructure worse than pre-disaster…
Area declines and vunerability increases.
What are the four subsections in the Hazard Management Cycle?
Mitigation, preparedness, response, recovery
Outline the concept of the Hazard Management Cycle.
The hazard management cycle is a continuous loop which explains an approach to managing a known hazard.
Preparedness is concerned with using evidence and data from previous events to plan for hazards associated with the event.
Responsse is concerned with deploying services and resources to save people and property from harm.
Recovery this is concerned with post disaster reconstruction and restoration of the local built and natural environment.
Mitigation is an extension to recovery. This is active steps taken to minimise the negative impacts associated with the hazard.
What is the crust fractured into
Tectonic plates
What is moving and made of molten silicates?
Mantle
What is the cooled down pieces of mantle?
Crust
What crust is denser and newer?
Oceanic
What crust is older, thickde and less dense?/
Continental
What is the upper part of mantle called?
Asthenosphere
What makes the crust move?
Convection currents
What is the junction between mantle and crust?
Moho discontinuity
What is the layer underneath mantle with less pressure?
Outer Core
What is the layer underneath mantle that is 3700 degrees celsius?
Solid core
What are the edges of tectonic plates called?
Plate margin
What is the name of our local plate?
Eurasian plate
What theory did Alfred Wegener publish?
Published 1912 that he belived a single continenent called Pangea existed about 300 million years ago. Theory of continental drift.
Evidence of Tectonic Theory?
Rock sequences in northern Scotland closely agree with those found in eastern Canada indicating were laid down under the same conditions in one location.
Fossiled remains of a plant which existed when coal was being formed have been located only in India and Antarctica.
Evidence of sea-floor spreading?
Alternating polarity of the rocks that from the oceanic crust. Iron particles in lava erupted on ocean floor aligned with Earth’s magnetic field. Lava solidifies providing permanent record of Earth’s polarity at time of eruption (paleomagnetism).
Convection currents
Plate dragged by convection current in the mantle.
Ridge push
Plate pushed by the weight of a mid-ocean ridge
Slab pull
Plate pulled by the weights of its cold, dense subducting section
Descriube the process of ridge push associated with plat emovement?
At constructive plate boundaries upwelling hot magma generates a buoyancy effect causing mid-ocean ridges to form. Gravity acts down the slope of this ridge meaning the plates experience a force that acts away from the plate boundary.
What is a destructive plate boundary?
Two plates are pushed together (converging).
What happens betweeen an oceanic and continental plate at a destructive plate boundary?
The denser oceanic crust is subducted beneath the less dense continental crust. Subduction zone= deep ocean trench
What forms at a destructive plate boundbary between an oceanic plate and a continental plate?
Pressure builds and this energy is released as earthquakes whilst due to the buckling of plateds fold mountains are also caused. Volcanoes occur as the mantle starts to melt the subducted oceanic plate.
What happens with two oceanic plates at a destructive plate boundary?
The denser of the two will subduct. Volcanic eruption occur creating volcanic island arcs. Eg. Hawaii
What will occur to two continental plates at a destructive plate boundary?
No suduction but the edges will buckle up to form fold mountains. No volcanoes and only earthquakes.
What is the main characteristic processes operating at destructive plate boundaries?
Suduction occurs where two plates converge. Subduction can lead to the formation such as deep sea trenches and island arcs.
What is an island arc?
As plates diverge, magma is forced to the surface. After subsequent underwater eruptions, eventually island arcs are formed along ridges, such as in the Mid Atlantic.
