Saving lives in earthquakes: successes and failures in seismic protection since 1960

Abstract

This paper will look at what we have and have not achieved in reducing the risks to human life from earthquakes in the last 50 years. It will review how success has been achieved in a few parts of the world, and consider what needs to be done by the scientific and engineering community globally to assist in the future task of bringing earthquake risks under control. The first part of the talk will re-examine what we know about the casualties from earthquakes in the last 50 years. Almost 80% of about 1 million deaths turn out to have been caused by just ten great earthquakes, together affecting a tiny proportion of the territory at risk from heavy ground shaking. The disparity between richer and poorer countries is also evident, not only in fatality rates, but also in their rates of change. But the existing casualty database turns out to be a very poor basis for observing such differences, not only because of the small number of lethal events, but also because of the very limited data on causes of death, types and causes of injury. These have been examined in detail in only a few, recent events. All that can be said with certainty is that a few wealthier earthquake-prone countries or regions have made impressive progress in reducing the risk of death from earthquakes, while most of the rest of the world has achieved comparatively little, and in some areas the problem has become much worse. The second part of the paper looks in more detail at what has been achieved country-by-country. Based on a new expert-group survey of key individuals involved in earthquake risk mitigation, it will examine what are perceived to be the successes and failures of risk mitigation in each country or group of countries. This survey will be used to highlight the achievements of those countries which have successfully tackled their earthquake risk; it will examine the processes of earthquake risk mitigation, from campaigning to retrofitting, and it will consider to what extent the achievement is the result of affluence, scientific and technical activity, political advocacy, public awareness, or the experience of destructive events. It will ask to what extent the approaches pioneered by the global leaders can be adopted by the rest. The final section of the talk will argue that it can be useful to view earthquake protection activity as a public health matter to be advanced in a manner similar to globally successful disease-control measures: it will be argued that the key components of such programmes—building in protection; harnessing new technology and creating a safety culture—must be the key components of earthquake protection strategies also. It will consider the contribution which the scientific and engineering community can make to bringing down today’s unacceptably high global earthquake risk. It will be suggested that this role is wider than commonly understood and needs to include:

Building-in protection

• Improving and simplifying information available for designers and self-builders of homes and infrastructure.

• Devising and running “building for safety” programmes to support local builders.

Harnessing new technologies

• Developing and testing cost-effective techniques for new construction and retrofit.

Creating a safety culture

• Involvement in raising public awareness.

• Political advocacy to support new legislation and other actions.

• Prioritising action on public buildings, especially schools and hospitals.

Examples of some of these actions will be given. International collaboration is essential to ensure that the resources and expertise available in the richer countries is shared with those most in need of help. And perhaps the most important single task for the engineering community is work to counter the widespread fatalistic attitude that future earthquakes are bound to be at least as destructive as those of the past.