seismic hazards Flashcards
focus
point underground where the earthquake originates from
epicentre
area above that is directly above the focus
liquefaction
saturated soil acts like a liquid due to vibrations of an earthquake, it become waker and more likely to subside when a large weight is on it
nature of seismic events
occur at plate boundaries
- san andreas fault in california
richter scale
frequency of an earthquake – the energy released is proportional to the magnitude
effects of seismic events
ground shaking
ground rupture
soil liquefaction
landslides
fires
effects on people and built environment
tsunamis
generated by shallow focus underwater earthquake
tsunamis effects depend on
- height of wave
- distance travelled
- coastal physical geography
- land use and population density
effects
drowning or injuries by water and debris
buildings and infrastructure washed away
fukushima quake 2011
9.0 magnitude
moved mainland 2.4m east
wave reached 40m
16000 death/6000 injured/2500 missing
managing seismic hazards - prediction
san andreas
- mapped areas on geographical information
- laser detec movement
prevention of seismic hazards
liquefaction can be prevented through soil stabilitisation
- avalanches can be prevented through controlled explosions
prepardness of seismic hazards
- awareness strategies
- warning systems
- evacuation plans and training
mitigation of seismic hazards
- search and rescue
- immediate emergency aid
- demolishing unsafe buildings
- tsunami wave breaks
adaptation of seismic events
- capitalise on opportunities
- insurance if risk
- changing lifestyle choices
- earthquake proof buildings
LIC - kathmandu nepal 2015 key information
- 8 magnitude
- epicentre 80km
- indo australian and eurasian plate boundaries
LIC - nepal 2015 primary effects
9000 died
20k injured
3m left homeless
electrcity, water, communication disconnected
1m need food, shelter and water
7000 crowded schools/hospitals
$5bn damage
LIC - nepal 2015 secondary effects
landslides and avalanches
mt everest killed 19 ppl
250 missing
70% live in temp shelters
LIC - nepal 2015 immediate responses
search and rescue
500k tents
financial aid pledged
300k migrated to seek shelter
social media used in search and rescue
LIC - nepal 2015 long term responses
roads repaired
7000 schools rebuilt
conference to discuss reconstruction
tourism to be boosted
HIC - christchurch NZ earthquake key info
14% live in rural areas
high life expectancy
- 6 magnitude
- focus 3.1 miles shallow
- epicentre 6 miles from christchurch
HIC - christchurch primary effects
180 killed
2000 injured
water and sewage pipes damaged
50% central city buildings destroyed
liquefaction damages roads
HIC - christchurch secondary effects
businesses out of action
emergency ervies interupted by road closures
lost benefits like tourism
$40bn damages
HIC - christchurch immediate responses
rescue from Japan, USA, UK and Austrialia
$5m aid money from australia
vulnerable people cared for
HICv - christchurch long term responses
- divided 4 zone
green: undamaged
orange: checks
white: unchecked
red: unstable - temp housing
- NGO helped with recovery
