In this chapter attention is centred on earthquakes and volcanic eruptions. These are highly energetic natural events that occur irrespective and independently of social action and any modification of the environment. We mention the significance of human action in relation to these natural trigger events in order to highlight not the insignificance of humanity in relation to these geological processes, but to underscore the fact that human action and inaction can nevertheless impact upon the outcomes of earthquakes and volcanic eruptions.
To illustrate this fact, we begin by comparing two hazard events which occurred 100 years apart. The first was on the island of Martinique (in the Caribbean), the second affected the city of Catas in the southern coastal region of Peru. At the most general level of root causes, there are familiar processes involved in determining unsafe conditions: the interests of the powerful, bureaucratic incompetence and ignorance. However, in the example of Catas, evacuation orders were given and there was some evidence of lessons having been learnt from experience.
The first eruption was in 1902, when an irresponsible and opportunistic political leader refused to order the evacuation of Martinique because of an impending election (in which he expected to benefit), despite the immediate threat of a volcanic eruption on the island. The consequence was the worst loss of life in a volcanic eruption in the entire twentieth century. One hundred years later, our second example relates to seismic hazard mapping in Peru, in the aftermath of an earthquake that led to an evacuation order to relocate a community, supposedly for their protection. But was public safety the reason for the order, or was there another motive to remove the community-of the discovery of oil on their land?
During the twentieth century around 98,000 people were reportedly killed in volcanic eruptions (CRED 2002). More than a third of this total occurred in just one event: the catastrophic 1902 eruption of Mount Pelée in Martinique (Caribbean), when the entire population of 29,000 in the town of St Pierre was killed in less than two minutes (Scarth 1997:138-141). This