Processes
and Hazards
Enquiry Question 2: Why do some tectonic hazards develop
into disasters?
, 1.4 Disaster occurrence can be explained by the relationship between hazards,
vulnerability, resilience and disaster.
A perceived natural event that has the potential to cause loss of life and
Hazard
damage to property.
Risk The probability of a hazard event occurring and causing loss of life.
A high risk combined with an inability of individuals and communities to
Vulnerability
cope.
A hazard becoming a reality in an event that causes death and damage to
Disaster
property. UN defines it as over 500 deaths.
The ability of a community or society exposed to hazards to resist and
Resilience recover from the effects of a hazard. It is the ability to 'spring back' from a
hazard or disaster.
Mega-Disaster Over 2,000 deaths, or 200,000 homeless or GDP reduced by 5%.
A natural tectonic event is a physical occurrence resulting from the movement or
deformation of the Earth's crust that does not affect people.
As soon as the event disrupts normal daily lives it becomes a hazard, and the level of
severity may increase to cause destruction to property and death.
A natural hazard becomes a disaster or mega-disaster when the number of deaths and the
cost of damage (socio-economic impacts) increase to higher levels. The UN suggests 500 or
more deaths as a disaster, with a mega-disaster being when there is:
Over 2,000 deaths, or
Over 200,000 made homeless, or
The GDP of a country is reduced by at least 5%, or
Dependence on aid from abroad for a year or more after the event
The Tohoku 2011 tsunami in Japan was a mega-disaster because there were over 20,000
deaths but only a 3.5% fall in GDP. The Haiti 2010 earthquake was a mega-disaster because
it cost 100% of GDP, had 222,000 deaths and needed international air for several years.
Insured
Cost (US Tectonic Tectonic Losses (US
Tectonic Event Deaths
$m) Event Event $m) and % of
Total Losses
Tangshan,
Tohoku Tohoku
China 40,000
Tsunami 210,000 655,000 Tsunami
Earthquake (19%)
2011 2011
1972
Christchurch,
Kobe Haiti
New Zealand 16,500
Earthquake 100,000 Earthquake 222,570
Earthquake (69%)
1995 2010
2011