tectonics 2 Flashcards
define resillience
Resilience is the ability of a community to cope with a hazard; some communities are better prepared than others so a hazard is less likely to become a disaster. It also includes the ability to return to normal following a disaster.
what things will countries have in place if they have a high resilience and high capacity to cope
they have emergency evacuation,
rescue and relief systems in place
they react by helping each other,
to reduce numbers affected, hazard-resistant design or land-use planning have reduced the numbers at risk
For these communities the threshold for disaster will be higher than for ones with low coping capacity.
what is the The Disaster Risk and Age Index
The Disaster Risk and Age Index, compiled by the UNISDR highlights the trends of ageing populations and the acceleration of risk in a world that is increasingly exposed to a range of hazard types. It signals how age should be an important factor in understanding vulnerability and the coping capacity of older generations.
What does the PAR model suggest
The par model looks at underlying causes of disaster
The PAR model suggests that the socio-economic context of a hazard is important. In poor, badly governed (root causes) places with rapid change and low capacity (dynamic pressures) and low coping capacity (unsafe conditions), disasters are likely.
It show how root causes, dynamic pressures and unsafe conditions combine with a natural hazard to create a disaster.
what creates vulnerability in the PAR model
Root causes
Dynamic pressures
Unsafe conditions
what are the two opposing forces in the PAR model that interact to create disaster
on one side are the processes that create vulnerability (shown as root causes, dynamic pressures and unsafe conditions)
on the other side is the hazard event itself ( e.g earthquake)
what where the root causes on the PAR model for Haiti
-Haiti had debt and needed to repay other countries so spent less on improving infrastructure
-corruption in the government
-80% of the population below the poverty line
-30-40% of gov budget came from foreign aid
what where the dynamic pressures on the PAR model for Haiti
-lack of urban planning on how buildings were constructed and where people lived
-lack of effective education systems
-lack of disaster management systems
-rapid urbanization led to vulnerable slum-like housing
-high pop density
significant deforestation and soil degradation leading to earthquake related landslides
what where the unsafe conditions on the PAR model for Haiti
-many buildings constructed on soft soil which amplified seismic waves
-illegal housing built in risky areas
-low GDP per capita of US $1300 so buildings constructed cheaply
-poor infrastructure
-b4 earthquake only 39% of people had access to safe water
what were the hazards on the PAR model for Haiti
Earthquakes and Landslides
when did the Haiti earthquake occur
2010
what was the hazard in Japan on the PAR model
magnitude 9 earthquake in 2011
tsunami reached 10 meters high in places
what was the root cause for Japan on the PAR model
-oversight in government when building nuclear power plant
what was the dynamic pressures for Japan on the PAR model
-nuclear powerplant not made to withstand the impact of the tsunami
what was the unsafe conditions for Japan on the PAR model
- The Fukushima nuclear powerplant was vulnerable and unsecure
what was the hazard in China on the PAR model
magnitude 7.9 earthquake in 2008
what was the root cause for China on the PAR model
-corrupt government officials and law enforcement
what was the dynamic pressure for China on the PAR model
-corrupt gov officials ignored building codes
-gov officials accepted bribes to allow builders to take short cuts
what was the unsafe conditions for China on the PAR model
-the resulting poorly constructed buildings could not withstand the ground shaking
how did recent building practices in the middle east contribute to the disaster in 2003
-there were unbaked clay houses
-rapid urbanization has allowed cheap construction but not safety from earthquakes
how did the government in the middle east try to mitigate the impacts of future earthquakes
created a leaflet containing the seismic risk areas and advice on making homes safer such as fixing free standing furniture to walls
what does the Moment Magnitude Scale measure
Earthquake magnitude is measured by the Moment Magnitude Scale, an updated version of the Richter scale. It measures the energy released during an earthquake. This is related to the amount of slip (movement) on the fault lane and the area of movement on the fault plane. MMS uses a logarithmic scale
- what does the The Mercalli scale measure
The Mercalli scale measures earthquake intensity on a scale of I-XII. This older scale measures what people actually feel during an earthquake, i.e. the intensity of the shaking effects not the energy released. It cannot be used to easily compare earthquakes as shaking experienced depends on building type and quality, ground conditions and other factors.
The relationship between magnitude and death toll is a weak one because:
some earthquakes cause serious secondary impacts, such as landslides and tsunami
earthquakes hitting urban areas have greater impacts than those in rural areas
level of development, and level of preparedness, affect death tolls
isolated, hard to reach places could have a higher death toll because rescue and relief take longer
a very high magnitude could not cause any deaths in an unoccupied area
what is the VEI (Volcanic Explosivity Index)
This measures that magnitude of a volcanic eruption. It ranges from 0-8 and is a composite index combining eruption height, volume of material (ash, gas, tephra) erupted and duration of eruption.
VEI eruptions from 0-3 are associated with shield volcanoes and basaltic eruptions at constructive plate boundaries and mid-plate hotspots. VEI eruptions from 4-7 occur at destructive plate margins, erupting high viscosity, high gas, high silica andestic magma. No modern human has ever experienced a VEI 8 supervolcano. caldera
what are hazard profiles
hazard profiles compare the characteristics of earthquakes, volcanoes and tsunamis (magnitude, speed of onset and areal extent, duration, frequency and spatial predictability). These allow for a better understanding of the nature of hazards and thus the risks associated with each
hazards with what characteristics display the greatest risk?
high magnitude, low frequency events - these are the least ‘expected’
rapid onset events with low spatial predictability -no warning
regional areal extent - affecting large numbers of people in a wide range of locations
what is the
Magnitude:
Speed of onset:
Areal extent:
Duration:
Frequency:
Spatial predictability:
for a Basaltic shield eruption
Basaltic shield eruption
Magnitude: small
Speed of onset: fairly slow
Areal extent: local
Duration: fairly long
Frequency: quite high
Spatial predictability: fairly precise
what is the
Magnitude:
Speed of onset:
Areal extent:
Duration:
Frequency:
Spatial predictability:
for an Andesitic composite cone eruption
Andesitic composite cone eruption
Magnitude: almost middling
Speed: middling
Areal extent: closer to local than regional
Duration: medium
Frequency: fairly low
Spacial predictability: fairly precise (but less so than basaltic shield)
what is the
Magnitude:
Speed of onset:
Areal extent:
Duration:
Frequency:
Spatial predictability:
for a Subduction zone earthquake
Subduction zone earthquake
Magnitude: more than medium
Speed: very rapid
Size: closer to regional than local
Duration: shortest
Frequency: closer to low than high
Spatial predictability: fairly random
what is the
Magnitude:
Speed of onset:
Areal extent:
Duration:
Frequency:
Spatial predictability:
for a Tsunami
Tsunami
Magnitude: largest
Speed of onset: rapid
Areal extent: largest
Duration: quite short
Frequency: high
Spatial predictability: highest
what are the factors that increase risk
-level of development
-density of people
-speed of onset
-education and preparation
Population growth
Urbanisation and urban sprawl
Environmental degradation
Loss of community memory about hazards
Very young, or very old population
Ageing, inadequate infrastructure
Greater reliance on power, water and communication systems
what factors mitigate risk
Warning and emergency-response systems
Economic wealth
Government disaster-assistance programmes
Insurance
Community initiatives
Scientific understanding
Hazard engineering
for the earthquake in Christchurch and Haiti, compare the number of deaths
Haiti= 300,000
Christchurch= 200
although magnitude was simmilar
why is Vanuatu considered to be at most risk
-its in a multihazard zone (composite cone volcanoes, eathquakes, tropical cyclones)
-isolated islands (no mobile phone service) spread over a large area
-poverty
-coping capacity and adaptive capacity is low due to lack of investment in education, healthcare and poor sanitation
