Tectonics EQ 2 Flashcards
Define hazard
The potential for a process to cause loss of life or property.
Define disaster
It is the realisation of a hazard when it causes significant impact on a population. A disaster is classified when a series of quantitative and qualitative levels have been reach.
Define risk and what is the equations for it
The probability of harmful consequences
Risk= Hazard x vulnerability
Define vulnerability
It is the ability to anticipate, cope, resist and recover from a natural hazard. Conditions are determined by physical, social, economic and environmental factors.
Define threshold
A set limit when a population has to adjust when the limit is broken.
What is the PAR model
It is a model that shows that a disaster is an interaction of two processes:
- Vulnerability
- Natural Hazards
What are the three parts of the PAR model
Root causes
Unsafe conditions
Dynamic pressures
These factors can be political, social or environmental
Give examples of root causes
- A corrupt government who lack commitment to improve infrastructure and standard of living. (Political)
- A lack of recourses (economic)
Root causes, cause unsafe conditions
Give examples of unsafe conditions
- Illegal housing built on unsafe land (social)
- Low GDP per capita so buildings were constructed cheaply and quickly (economic)
These unsafe conditions cause dynamic pressures
Examples of dynamic pressures
- A lack of disaster preparation, meaning that people or emergency services don’t know what to do (political/social)
- People still living in poverty so they don’t have resources to cope with hazards (social)
- A high population density so more people are affected (social)
Dynamic pressures increase the chance of a hazard happening
Japan earthquake/tsunami case study figures
Deaths- 15,000
Economic cost- $240bn
Magnitude- 9
Type of economy- developed
PAR model for Japan
Root cause- A nuclear power plant along the coast
Unsafe condition- Wasn’t built to withstand a tsunami
Dynamic pressure- A lack of basic safety procedures, planning, preparation at Fukushima power station
There was a high population density in cities
China earthquake case study figures
Deaths - 70,000
Economic cost - $125bn
Magnitude- 8
Economy- developing
PAR model for china
Root causes- corrupt government who ignored building codes and accepted bribes to allowed builders to make short cuts
Unsafe conditions- poorly built buildings
Dynamic conditions- Rapid urbanisation and rapid population growth
Haiti earthquake case study figures
Deaths- 220,000
Economic cost- $14bn
Magnitude- 7
Economy- undeveloped
Haiti PAR model
Root causes:
- Heavily in debt to US, German and French banks
- Corruption
Unsafe conditions:
- Houses built on unstable soil, a lot of illegal housing which was built on hill sides and was built cheaply and quickly
- Poor infrastructure
Dynamic pressures:
- High population density due to rapid urbanisation
- Lack of disaster management and preparedness
What does the moment magnitude scale measure
- Total amount of energy released
- Amplitude of seismic waves
- Amount of slippage
- Area of fault surface broken
- Resistance of affected rock
What does the Mercalli measure
Observations of people’s lived experiences of the disaster ranking them from 1 (hardly noticed) to 12 (catastrophic).
What does volcanic explosively index measure
Volume of ejecta (gas, rock, tephra, lava) and how high it is thrown into the atmosphere. Ranking from 0-8, where 0-4 is common and 4-8 high.
What is a hazard profile and examples
An analysis of different types of hazard, based in a range of criteria.
Bi-polar model
Which type of hazard is most severe as shown I hazard profiles
Tsunamis are the most severe having the highest magnitude, damage costs, highest average deaths, spatial area and slowest recovery rate.
Earthquakes have the fastest onset and coming second in deaths, magnitude, costs.
Then volcanoes having the longest duration but fewest deaths, cost onset.
What does the bi polar model measure
Magnitude Onset speed Duration Spatial area Frequency
Comparing hazard impacts in developing/emerging countries
Hazards in Developing countries are more severe as there vulnerability is higher due to dynamic pressure and don’t have resilience and coping capacity. This could be because of economic factors or natural hazards such as location .
Why is magnitude an important factor
Because even MEDC that have heavily invested into management strategies cannot cope with mega disasters.
However low magnitude earthquakes can be managed easily.
Why is areal extent an important factor
It affects the number of people affected also the large the area the more spread out your resources are such as emergency services. However small areas allow you resources to be concentrated
Why is frequency an important factor
The greater the frequency the more people are aware and educated on the hazard. If it is less frequent they might want to educate people as a management strategy.
