Understanding earthquakes: from myth to science

摘要

This paper is an explanation of how earthquakes have been interpreted by our predecessors since written records began. Before that we can only surmise that different societies had deities associated with mythological creatures able to cause earthquakes on one pretext or another. Here I have used the Japanese catfish—or ‘namazu’—creature to a large extent, partly because it is well-documented, but also because it is still used as a metaphor for earthquakes in official Japanese disaster prevention activities. Both the Bible and the Koran explain that earthquakes are God’s punishment for committed sin, and this idea was used until the seventeenth century, particularly by the Christian Church, in explaining their occurrence. The earliest rational approach appears to have come from the founding of Scientific Societies in Europe, beginning in Naples in 1560 and followed quickly by others in many European capital cities including London, where the Royal Society, founded in 1660, had the almost unique benefit of knowledge about earthquakes brought to London by its trade with many parts of the known world. Its Fellows had an opportunity to develop a more balanced approach, producing ideas which often centred on subterranean fire in the earth. Even so, the notion that God was the immediate cause had not disappeared. The 1755 the Great Lisbon earthquake was a seismic event in the religious and philosophical explanation of its cause. European philosophers, led by Leibnitz and Voltaire held contrary views about God and the world, with the latter concluding that earthquakes were caused by natural events with an unknown cause, about which the sins of the people had no influence. Rousseau was another philosopher of influence, initiating the concept of risk, arguing that it was the actions of people which turned an event into a disaster. These philosophers had the benefit of scientific knowledge about the world, originating with Copernicus and subsequently developed by those Scientific Societies referred to above which were created as early as the sixteenth century.