Hazard Flashcards
Hazard risk factors
Geographical location
Population density and distribution
Time
Natural factors
Frequency
Magnitude
Education
Level of development / wealth
name 3 types of tectonic natural hazards
earthquakes
volcanic eruptions
tsunamis
what is the difference between natural hazards and natural disasters
natural disasters are when the natural hazards actually affect people or their property
what caused the tectonic natural hazards
the movement of the tectonic plates
describe the inner core of the earth
a ball of solid iron and nickel
describe the outer core of the earth
very hot liquid
what is the mantle
semi molten rock moving very slowly around the earths core
what is the outer layer of the earth called
the crust
how thin is the crust
20km approximately
what are tectonic plates
areas of the crust divided into slabs
what do the tectonic plates float on
the mantle
what are the two main types of natural hazards
- geological hazards: caused by land and tectonic processes eg. volcanoes and earthquakes
- meteorological hazards: caused by weather and climate
eg. tropical storms and other extreme weather (heatwaves)
factors that affect hazard risks from natural hazards
.vulnerability: 1.the more people that are in the area exposed, greater probability they will be affected, 2. for example high population density on a flood plain is very vulnerable
.capacity to cope: 1.the better a population can cope with a extreme event, the lower the risk of them being effected, 2. for example hic are able to cope with flooding because they can afford defences
.nature of natural hazards: 1.type- the risk for some hazards at greater than others, 2.frequency- natural hazards that occur more often may carry a higher risk, 3.magnitude- more severe natural hazards tend to have the greatest effects
what is a primary effect
are the immediate impacts cause by the hazard itself:
.buildings and roads are destroyed
.people are injured or killed
.crops and water supplies can be damaged or contaminated
.electricity cables, gas pipes and communication networks can be damaged
what is the secondary effect
happen later on often as a result of the primary effects
.initial hazard can trigger other hazards eg. earthquakes-> tsunami
.aid and emergency
.a shortage of clean water lack of sanitation
.food shortages can occur if crops are damaged or livestock killed
.the country’s economy can be weakened, damage to business can cause unemployment and reconstruction can be expensive
what are examples of immediate responses
.evacuate people
.treat the injured and rescue
.recover dead bodies
.provide suppliers electricity and gas
.provide food,drink and shelter
.foreign governments or charities may send aid ,suppliers or financial donations
what are examples of long term responses
.repair homes or rehouse people
.repair buildings, roads, railways, bridges
.reconnect broken electricity, water , gas and communication connections
.improve building regulations so the can withstand similar hazards
.boost economic recovery eg. by promoting tourism
the earths crust is divided to tectonic plates, what do they float on ?
the mantle
what are the three types of plate margins?
. destructive margins
. constructive margins
. conservative margins
what direction do destructive margins move
toward each other
the plates meet, one is forced down into the the mantle and destroyed. volcanoes and ocean trenches occur here
what direction do constructive margin plates go?
move away from each other
magma rises from the mantle to fill the gap and cools, creating new crust.
what direction do the conservative margin plates go ?
sideways past each other orrr moving the same direction but at different speeds. creating friction. crust isn’t created or destroyed.
what plate margins do volcanoes appear on ?
destructive and constructive
what is magma when it reaches the surface
lava
how do earthquakes occur
- they are cause by tension that builds up at all three types of pants margins
- the plates eventually jerk past each other sending shock waves. theese vibrations are earthquakes
- the shock waves are spread out from the focus- the point in the in the earth where the earthquake starts. waves are stronger near the focus and cause more damage
- the epicentre is the lint on the earths surface straight above the focus
- earthquakes are measured using the moment magnitude scale
