Flashcards
Hazards
Cards in this deck (69)
- 1What is a natural hazard?Is a perceived event that threatens both life and property (loss of life and built environment)
- 2What are examples of natural hazards?Volcanic activity
Seismic events
Tropical storms - 3What are the common characteristics of natural hazards and their effect on people?Their origins are clear and effects distinctive
Short warning time
Exposure to risk is involuntary
Most losses of life and damage to property occur shortly after event
Scale and intensity require emergency response - 4What is risk?Exposure of people to a hazardous event presenting a potential threat to themselves, possessions and built environment
- 5Why may people put themselves at risk?Hazards events are unpredictable
Lack of alternatives (homes, land employment)
Changing the level of risk - places could change from safe to at risk
Cost/benefit - advantage may outweigh risk
Perception - 6What does vulnerability to natural hazards mean?Potential for loss
- 7What can alter the impact of a hazard on an individual?Wealth and level of technology
- 8How can richer people and countries protect themselves?Building sea defences
Constructing earthquake resistant buildings
Better emergency services - 9How can education help?More prepared as aware of risks
- 10Why do people react to the threat of hazards in different ways?Way in which individuals receive and process information
- 11What factors influence perception? (7)Socio economic status
Level of education
Occupation and employment
Religion, cultural background
Family and marital status
Past experience
Values, personality and expectations - 12What does perception of a hazard will ultimately determine?Course of action taken by individuals in order to modify the event or the responses they expect from governments and other organisations
- 13How may people perceive hazards?Fatalism
Adaptation
Fear - 14What is fatalism?Acceptance - part of life - inevitable
- 15What is adaptation?See that they can prepare for and therefore survive event by prediction, prevention or protection
- 16What is fear?The perception of the hazard is such that people feel so vulnerable that they can no longer face living there and move away
- 17What is frequency?The distribution of a hazard through time
- 18What is magnitude?The assessment of the size of the impact of a hazard event
- 19What are examples of community preparedness?Education
Awareness programs
Evacuation procedures
Emergency medical,food, water, shelter - 20What is integrated risk management?Process of considering the social economic and political factors involved in risk analysis
- 21What are primary effects?Effects that result directly from the event
- 22What is resilience?Sustained ability of individuals or communities to be able to utilise available resources to respond to, withstand and recover from the effects
- 23What are secondary effects?Effects that result from the primary impact of the hazard event
- 243Ps?Prediction
Prevention
Protection - 25What is prediction?Ability to give warnings so that the action can be taken to reduce impact of the hazard evenrs
- 26What does the disaster/response curve show?To show that hazard events can have varying impacts over time
- 27What is distribution?Refers to the spatial coverage of the hazard
- 28What does effects of natural hazard events mean?The effects are the impact that an event has upon both physical and human environments
- 29What is the core made up of?Dense rocks containing iron and nickel alloys
- 30What is the core divided up into?A solid inner core, and a molten outer one.
- 31Whats the temperature of this?5000°
- 32How is this heat mainly produced?As the result of two processes:
Primordial
Radiogenic - 33What is Primordial heat?Heat left over from the Earths formation
- 34What is Radiogenic heat?Heat produced by the radioactive decay of isotopes
- 35What is the mantle made up of?Molten and semi molten rocks containing lighter elements such as oxygen
- 36What does the lithosphere consist of?The crust and the rigid upper section of the mantle and is approx 80-90km thick
- 37Where does the asthenosphere lie?Beneath the lithosphere and is semi molten on which plates float and move
- 38What is the thickness, age and density of continental crust?T - 30-70km
A - Over 1500 million years
D - 2.6 - 39What is the thickness, age and density of oceanic crust?T - 6-10km
A - less than 200 million
D - 3.0 - 40What was Alfred Wegeners theory? (1912)That a single continent existed about 300 million years ago, which later split into two continents ect
- 41What geological evidence is there for the theory?Fit of south africa and west africa
- 42What biological evidence is there for the theory?Fossil brachiopods found in India limestone are comparable with similar fossils in Australia
- 43What was the theory unable to explain?How continental movement had taken place and his ideas gained little ground
- 44The movement of plates its responsible for producing what landforms?Ocean ridges
Rift valleys
Deep sea trenches
Island arcs
Young fold mountains
Volcanoes - 45How are ocean ridges formed?When plates move apart in oceanic areas, space between is then filled with basaltic lava upwelling to form a ridge
- 46How are rift valleys formed?when plates move apart on continental areas
areas of crust drop down in between 2 faults to form valley - 47How are deep sea trenches formed?Where oceanic and continental plates meet, denser oceanic plate is forced underneath lighter continental one
- 48How are island arcs formed?During subduction, descending plate encounters hotter surroundings, this coupled with the heat generated from friction, begins to melt the plate. Begins to rise towards the surface as magma, which eventually reach the surface and form volcanoes
- 49How are young fold mountains formed?Two continental plates meet and edges and sediment between are forced up
- 50How are lahars formed?By volcanic ash mixing with water and flowing downhill
- 51What is lava?Molten rock flowing onto the surface
- 52How are pyroclastic flows formed?Formed from a mixture of hot gas and tephra
- 53What is tephra?Solid matter ejected by a volcano into the air
- 54Where can volcanoes form?Rift valleys
Subduction zones
Hot spots
oceanic ridges - 55What are the primary effects of volcanoes?Tephra
Pyroclastic flows
Lava flows
Volcanic gases - 56What gases do these include?Carbon dioxide
carbon monoxide
Suplhur dioxide
Chlorine - 57What are the secondary effects of volcanoes?Lahars
Flooding
Landslides
Tsunamis
Acid rain
Climate change - 58What is an earthquake?As the crust of the Earth is constantly moving, there tends to be a slow build up of stress within the rock. When this pressure is released, parts of the surface experience, for a short period, an intense shaking motion
- 59What is retro fitting?In earthquake prone areas buildings and other structures can be fitted with devices such as shock absorbers and cross-bracing to make them more earthquake proof
- 60What is the point at which the pressure (for an earthquake) is released called?Focus
- 61What is the point immediately above this called?Epicentre
- 62How much damage to shallow focus earthquakes cause?The greatest damage and account for 75% of all earthquake energy released
- 63What type of scale is the Richter scale?Logarithmic scale
- 64Why is the mercalli scale unreliable?Depends on time of day, population and perception so isnt accurate
- 65What are the primary effects of earthquakes?Ground shaking
Ground Rupture - 66The severity of ground shaking depends on?Magnitude
Depth
Distance from epicentre
Geological conditions - 67What is ground rupture?Visible breaking and displacement of the earths surface
- 68What are the secondary effects of seismic events?Soil liquefaction
Landslides
Tsunamis
Fires
Effects on people and built environment - 69—
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- A level Geography Flashcards on Hazards, created by Erin Vernon on 30/11/2017.
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- Erin Vernon
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