Putting the Theory Into Practice: These theoretical ideas and principles have been implemented in practice. Oliver-Smith (1979) referred to a 400-year earthquake in examining the 31 May 1970 earthquake and rock avalanche in Yungay, Peru which killed most of the city's inhabitants. That 400 years is not the geological return period of the seismic or avalanche event, but instead refers to the fact that the root causes of the vulnerability, which were exposed during the event, took 400 years to build up, because the vulnerability that caused the disaster can be traced back to the Spanish conquest of the region, in terms of demographics, settlement locations, and ways of living. With that rationale, were the 26 December 2004 Indian Ocean tsunamis, that killed over 250,000 people across more than a dozen countries, 100- or 200-year events or more? Or has coastal vulnerability built up much faster than that and they were 20- or 40-year events, even though the earthquake and tsunamis had century-scale geological return periods? As another example, Etkin (1999) describes how reliance on structural flood defenses increases vulnerability over the long-term in a process termed risk transference. Structural defenses stop smaller floods and permit people to live in floodplains while remaining relatively dry. As a result of this false sense of security, vulnerability to floods increases (See also: Appendix (1). Most structural defenses must fail at some point, often by an event which exceeds or has different characteristics from the design flood. Then, the damage incurred by the flood is much greater than it would have been without the false sense of security imposed by the structural defenses. Short-term flood risk has decreased, but long-term flood risk has increased. Risk is transferred into the future and augmented, hence the term risk transference. This discussion leads to the tenet, extensively published and supported with evidence (see Appendix (1), that no disasters are natural; the term natural disaster is a misnomer. The event from nature, whether it be a thunderstorm or wildfire or landslide, is perfectly normal - and in many cases has significant advantages. Human decisions over the long-term build up vulnerability and that vulnerability is exposed by the event to yield the disaster. This notion can be extended further, as per the discussion in the opening paragraph (See also: Appendix (1), to explain that no hazards are natural; the term natural hazard is a misnomer. Hazard is a judgment foisted onto a normal - and often ecologically essential - environmental process because humans have made long-term choices which make the event hazardous to them. Extracting such principles from absolute and quantitative metrics is difficult, suggesting the need to think beyond numbers - and beyond analyzing only what is observed in the present. The discussion regarding the naturalness of hazards and disasters, however, acknowledges that viewpoints tend to depend on the definition adopted. Definitional arguments are not just academic exercises - they are needed for insurance, liability, and constitutional processes amongst others - but they can also sometimes obscure deeper meanings. As well, events to which it is challenging to reduce vulnerability include basaltic flood volcanic eruptions, large meteorite strikes, and gamma ray bursts from nearby stars - although the counterargument is that we have not tried to reduce such vulnerability. For understanding vulnerability, the important ethos is to accept human responsibility for the observed disaster ills and to accept human ability to reduce these ills. In research and for practice, the vulnerability literature suggests this ethos as the starting point for understanding - and then reducing the risks and impacts of - disasters