Natural hazards Flashcards
(72 cards)
Natural hazard definition?
Unexpected/uncontrollable natural event that has potential to affect lives of people
Hazard risk definition?
Probability of being affected by a natural event
What % people live in cities?
greater than 50%
4 factors increasing hazard risk?
Urbanisation, Level of development, Climate change, Building/farming on floodplains
How do tectonic plates move?
Convection currents + gravitational sliding
Oceanic crust?
Thin + dense
Continental crust?
thick + less dense
Constructive plate boundary?
Move apart- V+E
Destructive plate boundary?
Move toward-Oceanic (dense) subducts (forced down into mantle)-V+E
Conservative plate boundary?
Slide past along fault-E
Constructive example
Eurasian + North American
Destructive example
Nazca and south American
Conservative example
North American + Pacific (San Andreas Fault Line)
Earthquake primary effect
building collapse, ground split, ground shake
Earthquake secondary effect
Tsunami, fire, gas leak
Volcano primary effect
Lava flow, pyroclastic flow, ASH fall, fire
Volcano secondary effects
crop fail, livestock loss, water supply contamination
Earthquake immediate responses
Search + rescue
Volcano immediate responses
Evacuation, set up exclusion zone, medical care
Earthquake long term responses
rebuild schools, houses, hospitals, etc
Volcano long term responses
Rebuild infrastructure, resettle people, install monitoring equipment
ECONOMIC why do people live at risk of tectonic hazards?
Too poor to move, resources, jobs
SOCIAL why do people live at risk of tectonic hazards
Family and friends ties
Earthquake monitoring
Seismometers and lasers monitor earths movement