Tectonics Flashcards
what is the definition of a natural hazard?
a natural event that threatens or actually causes injury and death, as well as damage or destruction to property
what is the definition of a natural disaster?
when hazards have a significant impact on vulnerable populations, a hazard officially becomes a disaster when 100+ people are killed/ 100+ people are affected
what is vulnerability?
the ability of a community to cope with the impacts of a hazard e.g. quality of warning systems, emergency responses (& other factors) determine ability
what is risk?
the exposure of people to a hazardous event, probability of a hazard leading to loss of life/ livelihoods
what is the hazard risk equation?
risk = (hazard x exposure x vulnerability) / ability to cope
what is resilience?
ability of a community/country exposed to hazards to resist, absorb & recover from impacts of a hazard
what are the three main factors of the PAR model and what are their sub-categories?
- root causes (limited access to, ideologies)
- dynamic pressures (lack of, macro-forces)
- unsafe conditions
what factors influence the economic impacts of a tectonic event?
- level of development, per capita GDP
- total number of people affected
- speed of recovery from hazardous event
- degree of urbanisation
- amount of uninsured losses
what does the richter scale measure?
the amplitude of the waves produced by an earthquake , an absolute scale - it will measure the same on the richter scale wherever an earthquake is recorded
what does the modified mercalli scale measure?
the experienced impacts of an earthquake, a relative scale because people experience different amounts of shaking in different places, based on a series of key responses e.g. people awakening, movement of furniture, damage to structures
what does the MMS scale measure?
describes earthquakes in terms of energy released, magnitude is based on ‘seismic moment’ of earthquake (calculated by amount of slip on fault, area affected & Earth-rigidity factor)
what does the VEI measure?
relative measure of explosiveness of a volcanic eruption, calculated from volume of products released, height of eruption cloud, qualitative observations, logarithmic: increase of 1 index indicates a 10x more powerful eruption
what is a hazard profile?
a factor determining the social and economic impacts of an event, can be compared with profiles of other events
what criteria are used to build a hazard profile?
magnitude, speed of onset, duration, areal extent, spatial predictability, frequency
what non-economic aspects of development are also significant in affecting vulnerability and resilience?
access to education , access to healthcare, housing and governance
how do non-economic aspects affect vulnerability and resilience?
education: means people can be made more aware of hazard risks of living where they do and what to do in a hazard event
healthcare: the better the people’s health, the better they are at withstanding health and food risks resulting from hazard
housing: poorly built housing is usually unable to withstand earthquake shockwaves, leading to serious injury/death
governance: quality of governance can be critical
what is governance?
the way a country, city community, company etc is run by the people in control. good governance embodies recognition and practise of a range of principles e.g. transparency, rule of law, equity, consensus & participation
what three concepts are governance based on?
authority, decision making and accountability
what is poor governance and how does it increase vulnerability?
corruption, weak political organisation:
- failing to properly invest in infrastructure that might mitigate impacts of tectonic hazard e.g. failing to invest in warning systems, ‘hazard-proofing’ buildings etc
- being ill-prepared to deal with emergency situation immediately following a hazard
what geographical factors can increase hazard vulnerability?
- population density
- urbanisation
- isolation and inaccessibility
- community spirit
what factors in the 2003 Iran and 2015 Nepal earthquakes resulted in them becoming disasters?
- poorly constructed & vulnerable housing/other buildings
- poor emergency response - lack of equipment & specialised rescue & medical training (Bam, Iran: destruction of 3 main hospitals, Nepal: inaccessibility of stricken areas - remote mountainside locations with road rendered impassable by huge landslides)
