Seismic hazards (with case studies) Flashcards
What is Retrofitting?
Where buildings and other structures are fitted with shock absorbers and cross-bracing
How is the magnitude of earthquakes measured?
Richter scale
What are primary effects of seismic hazards
- Ground shaking
- Ground rupture (visible breaking of grounds surface)
What are secondary effects of seismic hazards
- Soil liquefaction
- Landslides/avalanches
- Tsunamis
- Fires
- Effects on people and the build environment
What is soil liquefaction?
When ground shakes soil with high water content lose their mechanical strength and behave like fluid
Names ways to protect against seismic hazards
- Hazard resistance structures
- Education
- Fire prevention (cut of gas)
- Emergency services
- Land-use planning
Which LIC had a seismic hazard (earthquake)?
Haiti
January 2010
7.0 MMS
Effects of Haiti earthquake
- Around 160,000 deaths, 300,000 injured
- 2.3 mil homeless
- Roads, airport and harbour blocked
- All hospitals in Port-au-Prince destroyed
- collapse of water supplies, outbreak of cholera (8000 died)
Response to Haiti earthquake
- US deployed 3,500 soldiers
- UK sent dogs to look for survivors
- Given aid but had little heavy lifting equipment so hard to look under buildings
- Slow recovery 3/4 years
Which HIC had a seismic event (earthquake)?
Christchurch (New zealand)
February 2011
6.3 MMS
Effects of Christchurch earthquake
- 185 deaths, 7000 injuries
- Harbour facilities damaged
- NZ$40 billion damage cost
- 100,000 dwellings destroyed
- Soil liquefaction
Why is New Zealand vulnerable?
Lies of ‘Pacific ring of fire’
Why is Haiti vulnerable?
Lies North American/Caribbean plates and between 2 fault lines
How can you prevent fires as a result of seismic events?
Smart meters - cut off all gas
How can emergency services be prepared for a disaster?
-Heavy lifting gear
-First aid training given
-Provide - tents, medical services, water purification,
search and rescue equipment
