Location of earthquakes and vocanoes: world divided into 7 plates. Two types of plate oceanic and continental. In the seperation of plates if where activity occurs as the earth is unstable here.
Destructive plate margins: plates move together. Two types : collision and subduction zones. Collision is where they hit head on and buckle going up forming a volcanoe. Subduction is when the oceanic goes under continental. Build up magma. pressure. Volcano.
Constructive Plate margins: plate move apart and magma fills the gap.
Conservative: two plate slide past each other causing pressure. Earthquake!
Why live in hazardous areas?
- Good physical and economic activities - climate and jobs
- fertile soils - volcanic rock
- mineral extraction - volcanic areas
- opportunitty to geneerate geothermal energy - volcanic
- development of tourism
Earthquakes: measured on Mercalli Scale, determines how much the earth is shaking and its likely effects and the Ricter Scale measure the energy on a scale of 1 to 10.
Effects: Primary = deaths, injury, damage to buildings, infraastructure
Secondary = fires, spread of disease, food, water, shelter, medical facilities
Why do earthquakes effect areas in different ways?
- distance to epicenter
- type of land
- how prepared an area is
Preparing For Earthquakes:
- train fire services
- stronger buildings - rubber shock absorbers
- gas electricity etc in flexible pipes
Volcanic eruptions produce:
- lava flows
- ash falls
- toxic gas
How can they be predicted?
- small tremors
- bulging cracks in volcano
- ground temperature increases
- small ash eruptions
- changes in gases
- hazard zoning
Colombian Earthquake Jan 1999
- homes lost
- water electricity cut off
- roads destroyed
- hospitals damaged
- fleet of fire trucks destroyed
- outbreaks of disease
- Sent for aid from other countries
- Effects so great because: poorly built buildings, unexpected, untrained, poor area, no water for days, homeless, industries destroyed
MT ST HELENS 18 MAY 1980
- dESTRUCTIVE PLATE MARGIN
- monitoring gave a warning
- landscape flattened
- farmland lost but better long term fertile soils
- forestry flattened replanted trees later
- communications lost
- fish died in lava flows
- tourism brings money
KOBE 7.2 ON RICTER SCALE JAN 1995
- 600 after shocks
- 6000 deaths
- 35000 injuries
- homes destroyed
- water, gas electricity disrupted
- high rise building demolished
- jobs lost
- more jobs made in rebuilding city
hazard zoning, strong buildings, fire resostant, increased monitoring of earthquake.