natural hazards

Created by

ellie

Cards (36)

Factors affecting hazard risk: 
-Development= HICs have better infrastructure than LICs
-Climate Change= The strength of frequency
-Urbanisation = Densely populated areas are more at risk(cities)
-Land use= changes in land use (deforestation, urbanisation) can increase risk
Primary and secondary effects= immediately after the hazard occurs
Immediate and long term responses= responses to the hazard overtime
Primary effects to tectonic hazards: 
-people injured or die
-Homes are destroyed
Secondary effects to tectonic hazards: 
-The economy slows down
-Burst water pipes
-contaminated water, disease (cholera)
immediate responses to tectonic hazards: 
-Rescue teams search for survivors
-provide treatment for injured people
long term responses to tectonic hazards: 
-rebuild and repair properties
NEE case study: Chile 
-occurred under sea, triggering a tsunami
Primary effects= 525 died, 1200 injured , 370000 homes destroyed, food prices rose by 10%
Secondary effects = roads destroyed, airports shut
Responses= 30,000 emergency shelters , housing reconstruction plan
LIC case study: Nepal 
Primary effects= 9000 died, 20000 injured, 3 million homeless , 30 hospitals destroyed
Secondary effects= ground shaking triggered landslides, outbreaks of cholera
Responses= 500,000 tents provided to shelter homeless, 7000 schools rebuilt
Why do people live in areas at risk of tectonic hazards? 
-Housing may be cheaper
what is the direction of plate movement at a constructive plate margin? 
-move away from each other
-earthquakes and volcanic activity
what is the direction of plate movement at a conservative plate margin? 
-slide past each other
-earthquakes only
what is the direction of plate movement at a destructive plate margin? 
-move towards each other
-Oceanic plate is subducted underneath the continental plate causing earthquakes and volcanic activity.
extreme weather 
weather that is not normal for an area and has negative impacts
low pressure = created at the surface where air is rising. Low pressure is associated with rain and cloud.
high pressure = created at surface where air is sinking. Associated with clear skies
coriolis effect = deflects wind to the right
hadley cell = transfers air and heat between the equator
ferrel cell = returns cooler air towards the equator but moves warmer air towards the poles
polar cell = the amount of solar insulation at the poles leads to cold air which sinks
conditions which cause a tropical storm:
-low latitude
-between 5-30 degrees North and South of the equator
-originate over oceans with temperatures above 26 degrees
-occur between summer and autumn
why do these conditions cause tropical storms? 
-being near the equator means temperatures are higher, so the air and sea is heated quickly. Air pressure is low and air rises.
-high ocean temperatures provides heat and moisture , warm air rises rapidly.
-summer and autumn are warmer months so there's low pressure.
the sequence of storm formation:
-ocean warms to a critical 26 degrees
-warm air rises, cools and condenses to create clouds (cumulonimbus clouds)
-this creates an area of low pressure. Air therefore rushes towards the storm (high pressure to low pressure). This creates strong winds.
-cool air sinks in the middle creating a low pressure eye. (calm conditions in eye of storm)
-the storm spins due to the earth's rotation.
tropical storm case study: Typhoon Haiyan 
Primary effects:
-6,000 killed , thousands of homes destroyed, 90% of city Tacloban destroyed.
Secondary effects:
-agricultural land destroyed, food price rose by 11%
-water supplies contaminated by sewage.
What were the responses to Typhoon Haiyan?
immediate responses:
-800,000 evacuated , government provided medical supplies
long term responses:
-cyclone shelters built
what extreme weather effects the UK? 
extreme cold = 'beast from the east' = risks to frost of cattle & crops
droughts/heatwaves = temperatures in summer of 40 degrees
storm events = heavy rainfall lead to flooding
extreme weather in the UK : Somerset levels
causes:
-heavy rainfall
-lack of dredging = rivers filled up with sediment, reducing amount of water it could hold
what were the impacts of somerset levels?
economic:
-costs of flooding were £10 million
social:
-600 houses flooded
environmental:
-removed oxygen from rivers killing fish
tectonic hazard: LIC case study, NEPAL 
primary effects:
-9,000 died , 20,000 injured , 3 millions left homeless
secondary effects:
-ground shaking triggered landslides
-outbreaks of cholera due to contaminated water
LIC case study NEPAL : responses 
immediate responses:
tents provided to shelter homeless
long term responses:
roads repaired
schools rebuilt
tectonic hazard: NEE case study, CHILE 
primary effects:
525 people died , 1200 injured , 3 hospitals destroyed
secondary effects:
airports closed
NEE case study CHILE : responses 
immediate responses:
emergency responses responded quickly
long term responses:
housing reconstruction plan by government
management strategies
Prediction: mainly predict volcanoes, hard to predict earthquakes
Protection: earthquake proof buildings to reduce impacts
Preparation: evacuation plans , food supplies
Monitoring: small earthquakes can mean a big one could occur
constructive plate margin: Processes
-Two plates move apart from eachother
-this creates a gap in the earth's crust
-magma from the mantle rises to fill this gap and a volcanic eruption occurs.
-small earthquakes also happen due to the movement of the magma
-Mainly shield volcanoes.
conservative plate margin: processes
-Two plates slide past eachother
-As they move, they get caught on eachother
-pressure builds up and is released as an earthquake when the plates suddenly jolt free.
-no volcanoes occur here.
destructive plate margin: processes
-Two plates moving towards eachother
-as the oceanic plate moves towards a continental plate.
-The denser oceanic plate is subducted beneath the continental plate.
-friction between the plates as they move causes an earth quake
-the oceanic plate melts in the mantle, causing magma to rise causing a volcanic eruption.
-Mainly composite volcanoes