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EQ2 tectonic processes and hazards - Coggle Diagram
EQ2 tectonic processes and hazards
natural hazard - a natural event ehich has the potential to harm people and property.
natural disaster the realisation (great impacts) of the hazards - harm that has occured, damage that has been done
risk - this is the potential or probability of a natural hazards causing harm and damage
resilience - the ability of a community or individuals to cope with the impacts of hazards.
the PAR model
- the framework for the vulnerability of places to natural hazards. it calculates the risk overall and vulnerability to the impacts of a disaster or a natural hazard.
root causes - are underlying issues a place faces such as limited access to food, power etc. as well as political and economic problems
dynamic pressures - include raped chance and low capacity to keep up with that change, such as urbanisation, investment etc.
unsafe conditions - include factors such as poor local economies, the physical environment etc.
haiti
root causes
per capita GDP US $1200, 50% of the population is under 20 years old
dynamic pressures
lack of education, training and investment, rapid population change and urbanisation
unsafe conditions
25% of people live in extreme poverty, 80% of port-au-Prince's housing is unplanned, informal slums
measuring earthquakes
MMS
- earthquake magnitude is measured by the moment magnitude scale, and 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, meaning that a magnitude 6 earthquakes has ten times more ground shaking than a magnitude 5
mercalli
the Mercalli scale measures earthquake intensity on a scale of I-XII. this older clase measure what people actually feel during an earthquake, i.e. the intensity of the shaking effects not the energy releases. it cannot be used to easily compare earthwuakes as shaking experienced ddpends on building typed and quality, ground conditions and other factors
measuring volcanoes
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 gas (ash, gas, tephre) erupted and duration of eruption.
hazard profiles
these are very useful way in which to map out the characteristics of hazard events - such as speed, extent and frequency.
the key to these is that it shown the relationships and correlations between different events.
hazards with the following characteristics present the highest risk
high magnitude low frequency events - these are the least 'expected' as, by definition, they are unlikely to have occured in living memory
rapid onset events with low spatial predictability - they could occur in numerous places and without warning .
regional areal extent - affecting large numbers of people in a wide range of locations
problems
unpredictability of hazards makes these models less effective at accurately representing human responses to hazards.
time frame is not represents well
quite vague in treating every hazards the same way.
2011 tohoku , Japan earthquake and tsunami
physical causes - underseas subduction zone - pacific and eurasian plates destructive).
people - 16,000 deaths , 6,000 injuries, 130,000 displanced
economy - $235bn cost, industrial production suspension.
environment - 40m wave tsunami, coastal subsidence of 0.6 metres, liquefaction
inequality - 0.910 HDI, well developed nation, good education system
governance - well prepared for tectonic events, planning and preparation complete.
geographical factors - epicentre 70 km off coast, 1 minute Tokyo warning signal, quake lasting 6 minutes.
2010 Haiti earthquake
physical causes - caribbean and North american plates (conservative - 7.0m
people - over 220,000 dead, 3000,000 injured, further 30% in poverty
economy - $8.5 billion damage, one third of commercial buildings destroyed
environment - water pollution, rubble lay on the landscape for months
inequality - 50% population in poverty before the quake, infrastructure poor quality
governance - historic debt problems, government legislations weak.
geographical factors - epicentre 25km from port au prince, no warning signals.